* [Bug] KASAN: slab-use-after-free Read in zswap_decompress @ 2024-12-17 10:52 Sam Sun 2024-12-17 16:30 ` Yosry Ahmed 0 siblings, 1 reply; 5+ messages in thread From: Sam Sun @ 2024-12-17 10:52 UTC (permalink / raw) To: linux-kernel, linux-mm Cc: syzkaller-bugs, akpm, chengming.zhou, Nhat Pham, yosryahmed, hannes Dear developers and maintainers, We encountered a slab-use-after-free bug while using our modified syzkaller. Kernel crash log is listed below. ================================================================== BUG: KASAN: slab-use-after-free in zswap_decompress+0x7d7/0x810 mm/zswap.c:988 Read of size 4 at addr ffff888027874044 by task kswapd0/92 CPU: 1 UID: 0 PID: 92 Comm: kswapd0 Not tainted 6.12.0-09435-g2c22dc1ee3a1 #11 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1b0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xc0/0x5e0 mm/kasan/report.c:489 kasan_report+0xbd/0xf0 mm/kasan/report.c:602 zswap_decompress+0x7d7/0x810 mm/zswap.c:988 zswap_writeback_entry+0x1e9/0x860 mm/zswap.c:1058 shrink_memcg_cb+0x213/0x360 mm/zswap.c:1163 __list_lru_walk_one+0x15e/0x490 mm/list_lru.c:301 list_lru_walk_one+0x3e/0x50 mm/list_lru.c:338 list_lru_shrink_walk include/linux/list_lru.h:240 [inline] zswap_shrinker_scan+0x135/0x220 mm/zswap.c:1197 do_shrink_slab+0x44e/0x1190 mm/shrinker.c:437 shrink_slab_memcg mm/shrinker.c:550 [inline] shrink_slab+0xb61/0x12a0 mm/shrinker.c:628 shrink_one+0x4ad/0x7c0 mm/vmscan.c:4836 shrink_many mm/vmscan.c:4897 [inline] lru_gen_shrink_node mm/vmscan.c:4975 [inline] shrink_node+0x269a/0x3d60 mm/vmscan.c:5956 kswapd_shrink_node mm/vmscan.c:6785 [inline] balance_pgdat+0xbe5/0x18c0 mm/vmscan.c:6977 kswapd+0x6ff/0xd60 mm/vmscan.c:7246 kthread+0x2ca/0x3b0 kernel/kthread.c:389 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Allocated by task 1: kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4283 [inline] __kmalloc_noprof+0x212/0x530 mm/slub.c:4295 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] __acomp_request_alloc_noprof include/crypto/internal/acompress.h:75 [inline] acomp_request_alloc+0x46/0x110 crypto/acompress.c:131 zswap_cpu_comp_prepare+0x1f4/0x470 mm/zswap.c:840 cpuhp_invoke_callback+0x26d/0x9d0 kernel/cpu.c:204 cpuhp_issue_call+0x1c1/0x8d0 kernel/cpu.c:2375 __cpuhp_state_add_instance_cpuslocked+0x26a/0x3c0 kernel/cpu.c:2437 __cpuhp_state_add_instance+0xd7/0x2e0 kernel/cpu.c:2458 cpuhp_state_add_instance include/linux/cpuhotplug.h:386 [inline] zswap_pool_create+0x2c3/0x5c0 mm/zswap.c:288 __zswap_pool_create_fallback mm/zswap.c:356 [inline] zswap_setup+0x3a5/0x820 mm/zswap.c:1781 zswap_init+0x2d/0x40 mm/zswap.c:1817 do_one_initcall+0x111/0x6d0 init/main.c:1266 do_initcall_level init/main.c:1328 [inline] do_initcalls init/main.c:1344 [inline] do_basic_setup init/main.c:1363 [inline] kernel_init_freeable+0x5ae/0x8a0 init/main.c:1577 kernel_init+0x1e/0x2d0 init/main.c:1466 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Freed by task 25: kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:582 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x54/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2338 [inline] slab_free mm/slub.c:4598 [inline] kfree+0x14e/0x4d0 mm/slub.c:4746 zswap_cpu_comp_dead+0xe3/0x1c0 mm/zswap.c:874 cpuhp_invoke_callback+0x564/0x9d0 kernel/cpu.c:216 __cpuhp_invoke_callback_range+0x104/0x220 kernel/cpu.c:965 cpuhp_invoke_callback_range kernel/cpu.c:989 [inline] cpuhp_down_callbacks kernel/cpu.c:1382 [inline] _cpu_down+0x41d/0xef0 kernel/cpu.c:1443 __cpu_down_maps_locked+0x6f/0x90 kernel/cpu.c:1473 work_for_cpu_fn+0x55/0xa0 kernel/workqueue.c:6719 process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x677/0xe90 kernel/workqueue.c:3391 kthread+0x2ca/0x3b0 kernel/kthread.c:389 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 The buggy address belongs to the object at ffff888027874000 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 68 bytes inside of freed 96-byte region [ffff888027874000, ffff888027874060) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x27874 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801b041280 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000200020 00000001f5000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid 1 (swapper/0), ts 20389586985, free_ts 18720773637 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2e7/0x350 mm/page_alloc.c:1556 prep_new_page mm/page_alloc.c:1564 [inline] get_page_from_freelist+0xe4e/0x2b20 mm/page_alloc.c:3474 __alloc_pages_noprof+0x219/0x21f0 mm/page_alloc.c:4751 alloc_pages_mpol_noprof+0x2b6/0x600 mm/mempolicy.c:2265 alloc_slab_page mm/slub.c:2408 [inline] allocate_slab mm/slub.c:2574 [inline] new_slab+0x2d5/0x420 mm/slub.c:2627 ___slab_alloc+0xbb7/0x1850 mm/slub.c:3815 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3905 __slab_alloc_node mm/slub.c:3980 [inline] slab_alloc_node mm/slub.c:4141 [inline] __do_kmalloc_node mm/slub.c:4282 [inline] __kmalloc_noprof+0x2ac/0x530 mm/slub.c:4295 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] __acomp_request_alloc_noprof include/crypto/internal/acompress.h:75 [inline] acomp_request_alloc+0x46/0x110 crypto/acompress.c:131 zswap_cpu_comp_prepare+0x1f4/0x470 mm/zswap.c:840 cpuhp_invoke_callback+0x26d/0x9d0 kernel/cpu.c:204 cpuhp_issue_call+0x1c1/0x8d0 kernel/cpu.c:2375 __cpuhp_state_add_instance_cpuslocked+0x26a/0x3c0 kernel/cpu.c:2437 __cpuhp_state_add_instance+0xd7/0x2e0 kernel/cpu.c:2458 cpuhp_state_add_instance include/linux/cpuhotplug.h:386 [inline] zswap_pool_create+0x2c3/0x5c0 mm/zswap.c:288 __zswap_pool_create_fallback mm/zswap.c:356 [inline] zswap_setup+0x3a5/0x820 mm/zswap.c:1781 page last free pid 54 tgid 54 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_unref_page+0x714/0x10c0 mm/page_alloc.c:2657 vfree+0x17e/0x890 mm/vmalloc.c:3382 delayed_vfree_work+0x57/0x70 mm/vmalloc.c:3303 process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x677/0xe90 kernel/workqueue.c:3391 kthread+0x2ca/0x3b0 kernel/kthread.c:389 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Memory state around the buggy address: ffff888027873f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888027873f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888027874000: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff888027874080: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc ffff888027874100: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc ================================================================== We also find a similar bug report in function zswap_store(), listed as below: ================================================================== BUG: KASAN: slab-use-after-free in zswap_compress mm/zswap.c:925 [inline] BUG: KASAN: slab-use-after-free in zswap_store_page mm/zswap.c:1426 [inline] BUG: KASAN: slab-use-after-free in zswap_store+0x2307/0x25e0 mm/zswap.c:1533 Read of size 4 at addr ffff8880219f6b44 by task kswapd0/88 CPU: 1 UID: 0 PID: 88 Comm: kswapd0 Tainted: G U 6.12.0-09435-g2c22dc1ee3a1 #11 Tainted: [U]=USER Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1b0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xc0/0x5e0 mm/kasan/report.c:489 kasan_report+0xbd/0xf0 mm/kasan/report.c:602 zswap_compress mm/zswap.c:925 [inline] zswap_store_page mm/zswap.c:1426 [inline] zswap_store+0x2307/0x25e0 mm/zswap.c:1533 swap_writepage+0x3a8/0xe50 mm/page_io.c:279 pageout+0x3b9/0xa90 mm/vmscan.c:689 shrink_folio_list+0x2988/0x4340 mm/vmscan.c:1367 evict_folios+0x72b/0x1a10 mm/vmscan.c:4593 try_to_shrink_lruvec+0x62b/0xa60 mm/vmscan.c:4789 shrink_one+0x417/0x7c0 mm/vmscan.c:4834 shrink_many mm/vmscan.c:4897 [inline] lru_gen_shrink_node mm/vmscan.c:4975 [inline] shrink_node+0x269a/0x3d60 mm/vmscan.c:5956 kswapd_shrink_node mm/vmscan.c:6785 [inline] balance_pgdat+0xbe5/0x18c0 mm/vmscan.c:6977 kswapd+0x6ff/0xd60 mm/vmscan.c:7246 kthread+0x2ca/0x3b0 kernel/kthread.c:389 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Allocated by task 1: kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4283 [inline] __kmalloc_noprof+0x212/0x530 mm/slub.c:4295 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] __acomp_request_alloc_noprof include/crypto/internal/acompress.h:75 [inline] acomp_request_alloc+0x46/0x110 crypto/acompress.c:131 zswap_cpu_comp_prepare+0x1f4/0x470 mm/zswap.c:840 cpuhp_invoke_callback+0x26d/0x9d0 kernel/cpu.c:204 cpuhp_issue_call+0x1c1/0x8d0 kernel/cpu.c:2375 __cpuhp_state_add_instance_cpuslocked+0x26a/0x3c0 kernel/cpu.c:2437 __cpuhp_state_add_instance+0xd7/0x2e0 kernel/cpu.c:2458 cpuhp_state_add_instance include/linux/cpuhotplug.h:386 [inline] zswap_pool_create+0x2c3/0x5c0 mm/zswap.c:288 __zswap_pool_create_fallback mm/zswap.c:356 [inline] zswap_setup+0x3a5/0x820 mm/zswap.c:1781 zswap_init+0x2d/0x40 mm/zswap.c:1817 do_one_initcall+0x111/0x6d0 init/main.c:1266 do_initcall_level init/main.c:1328 [inline] do_initcalls init/main.c:1344 [inline] do_basic_setup init/main.c:1363 [inline] kernel_init_freeable+0x5ae/0x8a0 init/main.c:1577 kernel_init+0x1e/0x2d0 init/main.c:1466 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Freed by task 901: kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:582 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x54/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2338 [inline] slab_free mm/slub.c:4598 [inline] kfree+0x14e/0x4d0 mm/slub.c:4746 zswap_cpu_comp_dead+0xe3/0x1c0 mm/zswap.c:874 cpuhp_invoke_callback+0x564/0x9d0 kernel/cpu.c:216 __cpuhp_invoke_callback_range+0x104/0x220 kernel/cpu.c:965 cpuhp_invoke_callback_range kernel/cpu.c:989 [inline] cpuhp_down_callbacks kernel/cpu.c:1382 [inline] _cpu_down+0x41d/0xef0 kernel/cpu.c:1443 __cpu_down_maps_locked+0x6f/0x90 kernel/cpu.c:1473 work_for_cpu_fn+0x55/0xa0 kernel/workqueue.c:6719 process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x677/0xe90 kernel/workqueue.c:3391 kthread+0x2ca/0x3b0 kernel/kthread.c:389 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 The buggy address belongs to the object at ffff8880219f6b00 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 68 bytes inside of freed 96-byte region [ffff8880219f6b00, ffff8880219f6b60) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x219f6 anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801b041280 ffffea0000887d00 dead000000000005 raw: 0000000000000000 0000000000200020 00000001f5000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid 1 (swapper/0), ts 15792736110, free_ts 14433067061 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2e7/0x350 mm/page_alloc.c:1556 prep_new_page mm/page_alloc.c:1564 [inline] get_page_from_freelist+0xe4e/0x2b20 mm/page_alloc.c:3474 __alloc_pages_noprof+0x219/0x21f0 mm/page_alloc.c:4751 alloc_pages_mpol_noprof+0x2b6/0x600 mm/mempolicy.c:2265 alloc_slab_page mm/slub.c:2408 [inline] allocate_slab mm/slub.c:2574 [inline] new_slab+0x2d5/0x420 mm/slub.c:2627 ___slab_alloc+0xbb7/0x1850 mm/slub.c:3815 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3905 __slab_alloc_node mm/slub.c:3980 [inline] slab_alloc_node mm/slub.c:4141 [inline] __kmalloc_cache_noprof+0x280/0x410 mm/slub.c:4309 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] usb_hub_create_port_device+0xbb/0xde0 drivers/usb/core/port.c:743 hub_configure drivers/usb/core/hub.c:1710 [inline] hub_probe+0x1ceb/0x2fc0 drivers/usb/core/hub.c:1965 usb_probe_interface+0x314/0x9f0 drivers/usb/core/driver.c:399 call_driver_probe drivers/base/dd.c:579 [inline] really_probe+0x252/0xa90 drivers/base/dd.c:658 __driver_probe_device+0x1df/0x450 drivers/base/dd.c:800 driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:830 __device_attach_driver+0x1db/0x2f0 drivers/base/dd.c:958 bus_for_each_drv+0x14c/0x1d0 drivers/base/bus.c:459 page last free pid 25 tgid 25 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_unref_page+0x714/0x10c0 mm/page_alloc.c:2657 vfree+0x17e/0x890 mm/vmalloc.c:3382 delayed_vfree_work+0x57/0x70 mm/vmalloc.c:3303 process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x677/0xe90 kernel/workqueue.c:3391 kthread+0x2ca/0x3b0 kernel/kthread.c:389 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Memory state around the buggy address: ffff8880219f6a00: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc ffff8880219f6a80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc >ffff8880219f6b00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff8880219f6b80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc ffff8880219f6c00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ================================================================== If you have any questions, please contact us. Best Regards, Yue ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Bug] KASAN: slab-use-after-free Read in zswap_decompress 2024-12-17 10:52 [Bug] KASAN: slab-use-after-free Read in zswap_decompress Sam Sun @ 2024-12-17 16:30 ` Yosry Ahmed 2024-12-17 19:32 ` Yosry Ahmed 0 siblings, 1 reply; 5+ messages in thread From: Yosry Ahmed @ 2024-12-17 16:30 UTC (permalink / raw) To: Sam Sun Cc: linux-kernel, linux-mm, syzkaller-bugs, akpm, chengming.zhou, Nhat Pham, hannes On Tue, Dec 17, 2024 at 2:52 AM Sam Sun <samsun1006219@gmail.com> wrote: > > Dear developers and maintainers, > > We encountered a slab-use-after-free bug while using our modified > syzkaller. Kernel crash log is listed below. Thanks for reporting this! This seems to be the problem that Johannes pointed out in: https://lore.kernel.org/lkml/20241113213007.GB1564047@cmpxchg.org/. Would you be able to check if the following diff fixes the problem? diff --git a/mm/zswap.c b/mm/zswap.c index 0030ce8fecfc5..089d70dee3246 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -875,6 +875,21 @@ static int zswap_cpu_comp_dead(unsigned int cpu, struct hlist_node *node) return 0; } +static void acomp_ctx_get_cpu(struct crypto_acomp_ctx *acomp_ctx) +{ + /* + * Prevent CPU hotplug from freeing this CPU's acomp_ctx until + * acomp_ctx_put_cpu(). + */ + cpus_read_lock(); + return raw_cpu_ptr +} + +static void acomp_ctx_put_cpu(void) +{ + cpus_read_unlock(); +} + static bool zswap_compress(struct folio *folio, struct zswap_entry *entry) { struct crypto_acomp_ctx *acomp_ctx; @@ -887,8 +902,7 @@ static bool zswap_compress(struct folio *folio, struct zswap_entry *entry) gfp_t gfp; u8 *dst; - acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); - + acomp_ctx = acomp_ctx_get_cpu(entry->pool->acomp_ctx); mutex_lock(&acomp_ctx->mutex); dst = acomp_ctx->buffer; @@ -944,6 +958,7 @@ static bool zswap_compress(struct folio *folio, struct zswap_entry *entry) zswap_reject_alloc_fail++; mutex_unlock(&acomp_ctx->mutex); + acomp_ctx_put_cpu(); return comp_ret == 0 && alloc_ret == 0; } @@ -954,7 +969,7 @@ static void zswap_decompress(struct zswap_entry *entry, struct folio *folio) struct crypto_acomp_ctx *acomp_ctx; u8 *src; - acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); + acomp_ctx = acompx_ctx_get_cpu(entry->pool->acomp_ctx); mutex_lock(&acomp_ctx->mutex); src = zpool_map_handle(zpool, entry->handle, ZPOOL_MM_RO); @@ -984,6 +999,7 @@ static void zswap_decompress(struct zswap_entry *entry, struct folio *folio) if (src != acomp_ctx->buffer) zpool_unmap_handle(zpool, entry->handle); + acomp_ctx_put_cpu(); } /********************************* > > > ================================================================== > BUG: KASAN: slab-use-after-free in zswap_decompress+0x7d7/0x810 mm/zswap.c:988 > Read of size 4 at addr ffff888027874044 by task kswapd0/92 > > CPU: 1 UID: 0 PID: 92 Comm: kswapd0 Not tainted 6.12.0-09435-g2c22dc1ee3a1 #11 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014 > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:94 [inline] > dump_stack_lvl+0x116/0x1b0 lib/dump_stack.c:120 > print_address_description mm/kasan/report.c:378 [inline] > print_report+0xc0/0x5e0 mm/kasan/report.c:489 > kasan_report+0xbd/0xf0 mm/kasan/report.c:602 > zswap_decompress+0x7d7/0x810 mm/zswap.c:988 > zswap_writeback_entry+0x1e9/0x860 mm/zswap.c:1058 > shrink_memcg_cb+0x213/0x360 mm/zswap.c:1163 > __list_lru_walk_one+0x15e/0x490 mm/list_lru.c:301 > list_lru_walk_one+0x3e/0x50 mm/list_lru.c:338 > list_lru_shrink_walk include/linux/list_lru.h:240 [inline] > zswap_shrinker_scan+0x135/0x220 mm/zswap.c:1197 > do_shrink_slab+0x44e/0x1190 mm/shrinker.c:437 > shrink_slab_memcg mm/shrinker.c:550 [inline] > shrink_slab+0xb61/0x12a0 mm/shrinker.c:628 > shrink_one+0x4ad/0x7c0 mm/vmscan.c:4836 > shrink_many mm/vmscan.c:4897 [inline] > lru_gen_shrink_node mm/vmscan.c:4975 [inline] > shrink_node+0x269a/0x3d60 mm/vmscan.c:5956 > kswapd_shrink_node mm/vmscan.c:6785 [inline] > balance_pgdat+0xbe5/0x18c0 mm/vmscan.c:6977 > kswapd+0x6ff/0xd60 mm/vmscan.c:7246 > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > </TASK> > > Allocated by task 1: > kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 > kasan_save_track+0x14/0x30 mm/kasan/common.c:68 > poison_kmalloc_redzone mm/kasan/common.c:377 [inline] > __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 > kasan_kmalloc include/linux/kasan.h:260 [inline] > __do_kmalloc_node mm/slub.c:4283 [inline] > __kmalloc_noprof+0x212/0x530 mm/slub.c:4295 > kmalloc_noprof include/linux/slab.h:905 [inline] > kzalloc_noprof include/linux/slab.h:1037 [inline] > __acomp_request_alloc_noprof include/crypto/internal/acompress.h:75 [inline] > acomp_request_alloc+0x46/0x110 crypto/acompress.c:131 > zswap_cpu_comp_prepare+0x1f4/0x470 mm/zswap.c:840 > cpuhp_invoke_callback+0x26d/0x9d0 kernel/cpu.c:204 > cpuhp_issue_call+0x1c1/0x8d0 kernel/cpu.c:2375 > __cpuhp_state_add_instance_cpuslocked+0x26a/0x3c0 kernel/cpu.c:2437 > __cpuhp_state_add_instance+0xd7/0x2e0 kernel/cpu.c:2458 > cpuhp_state_add_instance include/linux/cpuhotplug.h:386 [inline] > zswap_pool_create+0x2c3/0x5c0 mm/zswap.c:288 > __zswap_pool_create_fallback mm/zswap.c:356 [inline] > zswap_setup+0x3a5/0x820 mm/zswap.c:1781 > zswap_init+0x2d/0x40 mm/zswap.c:1817 > do_one_initcall+0x111/0x6d0 init/main.c:1266 > do_initcall_level init/main.c:1328 [inline] > do_initcalls init/main.c:1344 [inline] > do_basic_setup init/main.c:1363 [inline] > kernel_init_freeable+0x5ae/0x8a0 init/main.c:1577 > kernel_init+0x1e/0x2d0 init/main.c:1466 > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > Freed by task 25: > kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 > kasan_save_track+0x14/0x30 mm/kasan/common.c:68 > kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:582 > poison_slab_object mm/kasan/common.c:247 [inline] > __kasan_slab_free+0x54/0x70 mm/kasan/common.c:264 > kasan_slab_free include/linux/kasan.h:233 [inline] > slab_free_hook mm/slub.c:2338 [inline] > slab_free mm/slub.c:4598 [inline] > kfree+0x14e/0x4d0 mm/slub.c:4746 > zswap_cpu_comp_dead+0xe3/0x1c0 mm/zswap.c:874 > cpuhp_invoke_callback+0x564/0x9d0 kernel/cpu.c:216 > __cpuhp_invoke_callback_range+0x104/0x220 kernel/cpu.c:965 > cpuhp_invoke_callback_range kernel/cpu.c:989 [inline] > cpuhp_down_callbacks kernel/cpu.c:1382 [inline] > _cpu_down+0x41d/0xef0 kernel/cpu.c:1443 > __cpu_down_maps_locked+0x6f/0x90 kernel/cpu.c:1473 > work_for_cpu_fn+0x55/0xa0 kernel/workqueue.c:6719 > process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229 > process_scheduled_works kernel/workqueue.c:3310 [inline] > worker_thread+0x677/0xe90 kernel/workqueue.c:3391 > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > The buggy address belongs to the object at ffff888027874000 > which belongs to the cache kmalloc-96 of size 96 > The buggy address is located 68 bytes inside of > freed 96-byte region [ffff888027874000, ffff888027874060) > > The buggy address belongs to the physical page: > page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x27874 > flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) > page_type: f5(slab) > raw: 00fff00000000000 ffff88801b041280 dead000000000100 dead000000000122 > raw: 0000000000000000 0000000000200020 00000001f5000000 0000000000000000 > page dumped because: kasan: bad access detected > page_owner tracks the page as allocated > page last allocated via order 0, migratetype Unmovable, gfp_mask > 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid > 1 (swapper/0), ts 20389586985, free_ts 18720773637 > set_page_owner include/linux/page_owner.h:32 [inline] > post_alloc_hook+0x2e7/0x350 mm/page_alloc.c:1556 > prep_new_page mm/page_alloc.c:1564 [inline] > get_page_from_freelist+0xe4e/0x2b20 mm/page_alloc.c:3474 > __alloc_pages_noprof+0x219/0x21f0 mm/page_alloc.c:4751 > alloc_pages_mpol_noprof+0x2b6/0x600 mm/mempolicy.c:2265 > alloc_slab_page mm/slub.c:2408 [inline] > allocate_slab mm/slub.c:2574 [inline] > new_slab+0x2d5/0x420 mm/slub.c:2627 > ___slab_alloc+0xbb7/0x1850 mm/slub.c:3815 > __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3905 > __slab_alloc_node mm/slub.c:3980 [inline] > slab_alloc_node mm/slub.c:4141 [inline] > __do_kmalloc_node mm/slub.c:4282 [inline] > __kmalloc_noprof+0x2ac/0x530 mm/slub.c:4295 > kmalloc_noprof include/linux/slab.h:905 [inline] > kzalloc_noprof include/linux/slab.h:1037 [inline] > __acomp_request_alloc_noprof include/crypto/internal/acompress.h:75 [inline] > acomp_request_alloc+0x46/0x110 crypto/acompress.c:131 > zswap_cpu_comp_prepare+0x1f4/0x470 mm/zswap.c:840 > cpuhp_invoke_callback+0x26d/0x9d0 kernel/cpu.c:204 > cpuhp_issue_call+0x1c1/0x8d0 kernel/cpu.c:2375 > __cpuhp_state_add_instance_cpuslocked+0x26a/0x3c0 kernel/cpu.c:2437 > __cpuhp_state_add_instance+0xd7/0x2e0 kernel/cpu.c:2458 > cpuhp_state_add_instance include/linux/cpuhotplug.h:386 [inline] > zswap_pool_create+0x2c3/0x5c0 mm/zswap.c:288 > __zswap_pool_create_fallback mm/zswap.c:356 [inline] > zswap_setup+0x3a5/0x820 mm/zswap.c:1781 > page last free pid 54 tgid 54 stack trace: > reset_page_owner include/linux/page_owner.h:25 [inline] > free_pages_prepare mm/page_alloc.c:1127 [inline] > free_unref_page+0x714/0x10c0 mm/page_alloc.c:2657 > vfree+0x17e/0x890 mm/vmalloc.c:3382 > delayed_vfree_work+0x57/0x70 mm/vmalloc.c:3303 > process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229 > process_scheduled_works kernel/workqueue.c:3310 [inline] > worker_thread+0x677/0xe90 kernel/workqueue.c:3391 > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > Memory state around the buggy address: > ffff888027873f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > ffff888027873f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > >ffff888027874000: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > ^ > ffff888027874080: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc > ffff888027874100: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc > ================================================================== > We also find a similar bug report in function zswap_store(), listed as below: > > ================================================================== > BUG: KASAN: slab-use-after-free in zswap_compress mm/zswap.c:925 [inline] > BUG: KASAN: slab-use-after-free in zswap_store_page mm/zswap.c:1426 [inline] > BUG: KASAN: slab-use-after-free in zswap_store+0x2307/0x25e0 mm/zswap.c:1533 > Read of size 4 at addr ffff8880219f6b44 by task kswapd0/88 > > CPU: 1 UID: 0 PID: 88 Comm: kswapd0 Tainted: G U > 6.12.0-09435-g2c22dc1ee3a1 #11 > Tainted: [U]=USER > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014 > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:94 [inline] > dump_stack_lvl+0x116/0x1b0 lib/dump_stack.c:120 > print_address_description mm/kasan/report.c:378 [inline] > print_report+0xc0/0x5e0 mm/kasan/report.c:489 > kasan_report+0xbd/0xf0 mm/kasan/report.c:602 > zswap_compress mm/zswap.c:925 [inline] > zswap_store_page mm/zswap.c:1426 [inline] > zswap_store+0x2307/0x25e0 mm/zswap.c:1533 > swap_writepage+0x3a8/0xe50 mm/page_io.c:279 > pageout+0x3b9/0xa90 mm/vmscan.c:689 > shrink_folio_list+0x2988/0x4340 mm/vmscan.c:1367 > evict_folios+0x72b/0x1a10 mm/vmscan.c:4593 > try_to_shrink_lruvec+0x62b/0xa60 mm/vmscan.c:4789 > shrink_one+0x417/0x7c0 mm/vmscan.c:4834 > shrink_many mm/vmscan.c:4897 [inline] > lru_gen_shrink_node mm/vmscan.c:4975 [inline] > shrink_node+0x269a/0x3d60 mm/vmscan.c:5956 > kswapd_shrink_node mm/vmscan.c:6785 [inline] > balance_pgdat+0xbe5/0x18c0 mm/vmscan.c:6977 > kswapd+0x6ff/0xd60 mm/vmscan.c:7246 > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > </TASK> > > Allocated by task 1: > kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 > kasan_save_track+0x14/0x30 mm/kasan/common.c:68 > poison_kmalloc_redzone mm/kasan/common.c:377 [inline] > __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 > kasan_kmalloc include/linux/kasan.h:260 [inline] > __do_kmalloc_node mm/slub.c:4283 [inline] > __kmalloc_noprof+0x212/0x530 mm/slub.c:4295 > kmalloc_noprof include/linux/slab.h:905 [inline] > kzalloc_noprof include/linux/slab.h:1037 [inline] > __acomp_request_alloc_noprof include/crypto/internal/acompress.h:75 [inline] > acomp_request_alloc+0x46/0x110 crypto/acompress.c:131 > zswap_cpu_comp_prepare+0x1f4/0x470 mm/zswap.c:840 > cpuhp_invoke_callback+0x26d/0x9d0 kernel/cpu.c:204 > cpuhp_issue_call+0x1c1/0x8d0 kernel/cpu.c:2375 > __cpuhp_state_add_instance_cpuslocked+0x26a/0x3c0 kernel/cpu.c:2437 > __cpuhp_state_add_instance+0xd7/0x2e0 kernel/cpu.c:2458 > cpuhp_state_add_instance include/linux/cpuhotplug.h:386 [inline] > zswap_pool_create+0x2c3/0x5c0 mm/zswap.c:288 > __zswap_pool_create_fallback mm/zswap.c:356 [inline] > zswap_setup+0x3a5/0x820 mm/zswap.c:1781 > zswap_init+0x2d/0x40 mm/zswap.c:1817 > do_one_initcall+0x111/0x6d0 init/main.c:1266 > do_initcall_level init/main.c:1328 [inline] > do_initcalls init/main.c:1344 [inline] > do_basic_setup init/main.c:1363 [inline] > kernel_init_freeable+0x5ae/0x8a0 init/main.c:1577 > kernel_init+0x1e/0x2d0 init/main.c:1466 > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > Freed by task 901: > kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 > kasan_save_track+0x14/0x30 mm/kasan/common.c:68 > kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:582 > poison_slab_object mm/kasan/common.c:247 [inline] > __kasan_slab_free+0x54/0x70 mm/kasan/common.c:264 > kasan_slab_free include/linux/kasan.h:233 [inline] > slab_free_hook mm/slub.c:2338 [inline] > slab_free mm/slub.c:4598 [inline] > kfree+0x14e/0x4d0 mm/slub.c:4746 > zswap_cpu_comp_dead+0xe3/0x1c0 mm/zswap.c:874 > cpuhp_invoke_callback+0x564/0x9d0 kernel/cpu.c:216 > __cpuhp_invoke_callback_range+0x104/0x220 kernel/cpu.c:965 > cpuhp_invoke_callback_range kernel/cpu.c:989 [inline] > cpuhp_down_callbacks kernel/cpu.c:1382 [inline] > _cpu_down+0x41d/0xef0 kernel/cpu.c:1443 > __cpu_down_maps_locked+0x6f/0x90 kernel/cpu.c:1473 > work_for_cpu_fn+0x55/0xa0 kernel/workqueue.c:6719 > process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229 > process_scheduled_works kernel/workqueue.c:3310 [inline] > worker_thread+0x677/0xe90 kernel/workqueue.c:3391 > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > The buggy address belongs to the object at ffff8880219f6b00 > which belongs to the cache kmalloc-96 of size 96 > The buggy address is located 68 bytes inside of > freed 96-byte region [ffff8880219f6b00, ffff8880219f6b60) > > The buggy address belongs to the physical page: > page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x219f6 > anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) > page_type: f5(slab) > raw: 00fff00000000000 ffff88801b041280 ffffea0000887d00 dead000000000005 > raw: 0000000000000000 0000000000200020 00000001f5000000 0000000000000000 > page dumped because: kasan: bad access detected > page_owner tracks the page as allocated > page last allocated via order 0, migratetype Unmovable, gfp_mask > 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid > 1 (swapper/0), ts 15792736110, free_ts 14433067061 > set_page_owner include/linux/page_owner.h:32 [inline] > post_alloc_hook+0x2e7/0x350 mm/page_alloc.c:1556 > prep_new_page mm/page_alloc.c:1564 [inline] > get_page_from_freelist+0xe4e/0x2b20 mm/page_alloc.c:3474 > __alloc_pages_noprof+0x219/0x21f0 mm/page_alloc.c:4751 > alloc_pages_mpol_noprof+0x2b6/0x600 mm/mempolicy.c:2265 > alloc_slab_page mm/slub.c:2408 [inline] > allocate_slab mm/slub.c:2574 [inline] > new_slab+0x2d5/0x420 mm/slub.c:2627 > ___slab_alloc+0xbb7/0x1850 mm/slub.c:3815 > __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3905 > __slab_alloc_node mm/slub.c:3980 [inline] > slab_alloc_node mm/slub.c:4141 [inline] > __kmalloc_cache_noprof+0x280/0x410 mm/slub.c:4309 > kmalloc_noprof include/linux/slab.h:901 [inline] > kzalloc_noprof include/linux/slab.h:1037 [inline] > usb_hub_create_port_device+0xbb/0xde0 drivers/usb/core/port.c:743 > hub_configure drivers/usb/core/hub.c:1710 [inline] > hub_probe+0x1ceb/0x2fc0 drivers/usb/core/hub.c:1965 > usb_probe_interface+0x314/0x9f0 drivers/usb/core/driver.c:399 > call_driver_probe drivers/base/dd.c:579 [inline] > really_probe+0x252/0xa90 drivers/base/dd.c:658 > __driver_probe_device+0x1df/0x450 drivers/base/dd.c:800 > driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:830 > __device_attach_driver+0x1db/0x2f0 drivers/base/dd.c:958 > bus_for_each_drv+0x14c/0x1d0 drivers/base/bus.c:459 > page last free pid 25 tgid 25 stack trace: > reset_page_owner include/linux/page_owner.h:25 [inline] > free_pages_prepare mm/page_alloc.c:1127 [inline] > free_unref_page+0x714/0x10c0 mm/page_alloc.c:2657 > vfree+0x17e/0x890 mm/vmalloc.c:3382 > delayed_vfree_work+0x57/0x70 mm/vmalloc.c:3303 > process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229 > process_scheduled_works kernel/workqueue.c:3310 [inline] > worker_thread+0x677/0xe90 kernel/workqueue.c:3391 > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > Memory state around the buggy address: > ffff8880219f6a00: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc > ffff8880219f6a80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc > >ffff8880219f6b00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > ^ > ffff8880219f6b80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc > ffff8880219f6c00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > ================================================================== > If you have any questions, please contact us. > > Best Regards, > Yue ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Bug] KASAN: slab-use-after-free Read in zswap_decompress 2024-12-17 16:30 ` Yosry Ahmed @ 2024-12-17 19:32 ` Yosry Ahmed 2024-12-18 9:17 ` Sam Sun 0 siblings, 1 reply; 5+ messages in thread From: Yosry Ahmed @ 2024-12-17 19:32 UTC (permalink / raw) To: Sam Sun Cc: linux-kernel, linux-mm, syzkaller-bugs, akpm, chengming.zhou, Nhat Pham, hannes [-- Attachment #1: Type: text/plain, Size: 19735 bytes --] On Tue, Dec 17, 2024 at 8:30 AM Yosry Ahmed <yosryahmed@google.com> wrote: > > On Tue, Dec 17, 2024 at 2:52 AM Sam Sun <samsun1006219@gmail.com> wrote: > > > > Dear developers and maintainers, > > > > We encountered a slab-use-after-free bug while using our modified > > syzkaller. Kernel crash log is listed below. > > > Thanks for reporting this! > > This seems to be the problem that Johannes pointed out in: > https://lore.kernel.org/lkml/20241113213007.GB1564047@cmpxchg.org/. > > Would you be able to check if the following diff fixes the problem? I sent a poached semi-staged git diff, apologies. Please try the proper patch attached instead. > > diff --git a/mm/zswap.c b/mm/zswap.c > index 0030ce8fecfc5..089d70dee3246 100644 > --- a/mm/zswap.c > +++ b/mm/zswap.c > @@ -875,6 +875,21 @@ static int zswap_cpu_comp_dead(unsigned int cpu, > struct hlist_node *node) > return 0; > } > > +static void acomp_ctx_get_cpu(struct crypto_acomp_ctx *acomp_ctx) > +{ > + /* > + * Prevent CPU hotplug from freeing this CPU's acomp_ctx until > + * acomp_ctx_put_cpu(). > + */ > + cpus_read_lock(); > + return raw_cpu_ptr > +} > + > +static void acomp_ctx_put_cpu(void) > +{ > + cpus_read_unlock(); > +} > + > static bool zswap_compress(struct folio *folio, struct zswap_entry *entry) > { > struct crypto_acomp_ctx *acomp_ctx; > @@ -887,8 +902,7 @@ static bool zswap_compress(struct folio *folio, > struct zswap_entry *entry) > gfp_t gfp; > u8 *dst; > > - acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); > - > + acomp_ctx = acomp_ctx_get_cpu(entry->pool->acomp_ctx); > mutex_lock(&acomp_ctx->mutex); > > dst = acomp_ctx->buffer; > @@ -944,6 +958,7 @@ static bool zswap_compress(struct folio *folio, > struct zswap_entry *entry) > zswap_reject_alloc_fail++; > > mutex_unlock(&acomp_ctx->mutex); > + acomp_ctx_put_cpu(); > return comp_ret == 0 && alloc_ret == 0; > } > > @@ -954,7 +969,7 @@ static void zswap_decompress(struct zswap_entry > *entry, struct folio *folio) > struct crypto_acomp_ctx *acomp_ctx; > u8 *src; > > - acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); > + acomp_ctx = acompx_ctx_get_cpu(entry->pool->acomp_ctx); > mutex_lock(&acomp_ctx->mutex); > > src = zpool_map_handle(zpool, entry->handle, ZPOOL_MM_RO); > @@ -984,6 +999,7 @@ static void zswap_decompress(struct zswap_entry > *entry, struct folio *folio) > > if (src != acomp_ctx->buffer) > zpool_unmap_handle(zpool, entry->handle); > + acomp_ctx_put_cpu(); > } > > /********************************* > > > > > > > > ================================================================== > > BUG: KASAN: slab-use-after-free in zswap_decompress+0x7d7/0x810 mm/zswap.c:988 > > Read of size 4 at addr ffff888027874044 by task kswapd0/92 > > > > CPU: 1 UID: 0 PID: 92 Comm: kswapd0 Not tainted 6.12.0-09435-g2c22dc1ee3a1 #11 > > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > > rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014 > > Call Trace: > > <TASK> > > __dump_stack lib/dump_stack.c:94 [inline] > > dump_stack_lvl+0x116/0x1b0 lib/dump_stack.c:120 > > print_address_description mm/kasan/report.c:378 [inline] > > print_report+0xc0/0x5e0 mm/kasan/report.c:489 > > kasan_report+0xbd/0xf0 mm/kasan/report.c:602 > > zswap_decompress+0x7d7/0x810 mm/zswap.c:988 > > zswap_writeback_entry+0x1e9/0x860 mm/zswap.c:1058 > > shrink_memcg_cb+0x213/0x360 mm/zswap.c:1163 > > __list_lru_walk_one+0x15e/0x490 mm/list_lru.c:301 > > list_lru_walk_one+0x3e/0x50 mm/list_lru.c:338 > > list_lru_shrink_walk include/linux/list_lru.h:240 [inline] > > zswap_shrinker_scan+0x135/0x220 mm/zswap.c:1197 > > do_shrink_slab+0x44e/0x1190 mm/shrinker.c:437 > > shrink_slab_memcg mm/shrinker.c:550 [inline] > > shrink_slab+0xb61/0x12a0 mm/shrinker.c:628 > > shrink_one+0x4ad/0x7c0 mm/vmscan.c:4836 > > shrink_many mm/vmscan.c:4897 [inline] > > lru_gen_shrink_node mm/vmscan.c:4975 [inline] > > shrink_node+0x269a/0x3d60 mm/vmscan.c:5956 > > kswapd_shrink_node mm/vmscan.c:6785 [inline] > > balance_pgdat+0xbe5/0x18c0 mm/vmscan.c:6977 > > kswapd+0x6ff/0xd60 mm/vmscan.c:7246 > > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > </TASK> > > > > Allocated by task 1: > > kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 > > kasan_save_track+0x14/0x30 mm/kasan/common.c:68 > > poison_kmalloc_redzone mm/kasan/common.c:377 [inline] > > __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 > > kasan_kmalloc include/linux/kasan.h:260 [inline] > > __do_kmalloc_node mm/slub.c:4283 [inline] > > __kmalloc_noprof+0x212/0x530 mm/slub.c:4295 > > kmalloc_noprof include/linux/slab.h:905 [inline] > > kzalloc_noprof include/linux/slab.h:1037 [inline] > > __acomp_request_alloc_noprof include/crypto/internal/acompress.h:75 [inline] > > acomp_request_alloc+0x46/0x110 crypto/acompress.c:131 > > zswap_cpu_comp_prepare+0x1f4/0x470 mm/zswap.c:840 > > cpuhp_invoke_callback+0x26d/0x9d0 kernel/cpu.c:204 > > cpuhp_issue_call+0x1c1/0x8d0 kernel/cpu.c:2375 > > __cpuhp_state_add_instance_cpuslocked+0x26a/0x3c0 kernel/cpu.c:2437 > > __cpuhp_state_add_instance+0xd7/0x2e0 kernel/cpu.c:2458 > > cpuhp_state_add_instance include/linux/cpuhotplug.h:386 [inline] > > zswap_pool_create+0x2c3/0x5c0 mm/zswap.c:288 > > __zswap_pool_create_fallback mm/zswap.c:356 [inline] > > zswap_setup+0x3a5/0x820 mm/zswap.c:1781 > > zswap_init+0x2d/0x40 mm/zswap.c:1817 > > do_one_initcall+0x111/0x6d0 init/main.c:1266 > > do_initcall_level init/main.c:1328 [inline] > > do_initcalls init/main.c:1344 [inline] > > do_basic_setup init/main.c:1363 [inline] > > kernel_init_freeable+0x5ae/0x8a0 init/main.c:1577 > > kernel_init+0x1e/0x2d0 init/main.c:1466 > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > Freed by task 25: > > kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 > > kasan_save_track+0x14/0x30 mm/kasan/common.c:68 > > kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:582 > > poison_slab_object mm/kasan/common.c:247 [inline] > > __kasan_slab_free+0x54/0x70 mm/kasan/common.c:264 > > kasan_slab_free include/linux/kasan.h:233 [inline] > > slab_free_hook mm/slub.c:2338 [inline] > > slab_free mm/slub.c:4598 [inline] > > kfree+0x14e/0x4d0 mm/slub.c:4746 > > zswap_cpu_comp_dead+0xe3/0x1c0 mm/zswap.c:874 > > cpuhp_invoke_callback+0x564/0x9d0 kernel/cpu.c:216 > > __cpuhp_invoke_callback_range+0x104/0x220 kernel/cpu.c:965 > > cpuhp_invoke_callback_range kernel/cpu.c:989 [inline] > > cpuhp_down_callbacks kernel/cpu.c:1382 [inline] > > _cpu_down+0x41d/0xef0 kernel/cpu.c:1443 > > __cpu_down_maps_locked+0x6f/0x90 kernel/cpu.c:1473 > > work_for_cpu_fn+0x55/0xa0 kernel/workqueue.c:6719 > > process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229 > > process_scheduled_works kernel/workqueue.c:3310 [inline] > > worker_thread+0x677/0xe90 kernel/workqueue.c:3391 > > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > The buggy address belongs to the object at ffff888027874000 > > which belongs to the cache kmalloc-96 of size 96 > > The buggy address is located 68 bytes inside of > > freed 96-byte region [ffff888027874000, ffff888027874060) > > > > The buggy address belongs to the physical page: > > page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x27874 > > flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) > > page_type: f5(slab) > > raw: 00fff00000000000 ffff88801b041280 dead000000000100 dead000000000122 > > raw: 0000000000000000 0000000000200020 00000001f5000000 0000000000000000 > > page dumped because: kasan: bad access detected > > page_owner tracks the page as allocated > > page last allocated via order 0, migratetype Unmovable, gfp_mask > > 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid > > 1 (swapper/0), ts 20389586985, free_ts 18720773637 > > set_page_owner include/linux/page_owner.h:32 [inline] > > post_alloc_hook+0x2e7/0x350 mm/page_alloc.c:1556 > > prep_new_page mm/page_alloc.c:1564 [inline] > > get_page_from_freelist+0xe4e/0x2b20 mm/page_alloc.c:3474 > > __alloc_pages_noprof+0x219/0x21f0 mm/page_alloc.c:4751 > > alloc_pages_mpol_noprof+0x2b6/0x600 mm/mempolicy.c:2265 > > alloc_slab_page mm/slub.c:2408 [inline] > > allocate_slab mm/slub.c:2574 [inline] > > new_slab+0x2d5/0x420 mm/slub.c:2627 > > ___slab_alloc+0xbb7/0x1850 mm/slub.c:3815 > > __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3905 > > __slab_alloc_node mm/slub.c:3980 [inline] > > slab_alloc_node mm/slub.c:4141 [inline] > > __do_kmalloc_node mm/slub.c:4282 [inline] > > __kmalloc_noprof+0x2ac/0x530 mm/slub.c:4295 > > kmalloc_noprof include/linux/slab.h:905 [inline] > > kzalloc_noprof include/linux/slab.h:1037 [inline] > > __acomp_request_alloc_noprof include/crypto/internal/acompress.h:75 [inline] > > acomp_request_alloc+0x46/0x110 crypto/acompress.c:131 > > zswap_cpu_comp_prepare+0x1f4/0x470 mm/zswap.c:840 > > cpuhp_invoke_callback+0x26d/0x9d0 kernel/cpu.c:204 > > cpuhp_issue_call+0x1c1/0x8d0 kernel/cpu.c:2375 > > __cpuhp_state_add_instance_cpuslocked+0x26a/0x3c0 kernel/cpu.c:2437 > > __cpuhp_state_add_instance+0xd7/0x2e0 kernel/cpu.c:2458 > > cpuhp_state_add_instance include/linux/cpuhotplug.h:386 [inline] > > zswap_pool_create+0x2c3/0x5c0 mm/zswap.c:288 > > __zswap_pool_create_fallback mm/zswap.c:356 [inline] > > zswap_setup+0x3a5/0x820 mm/zswap.c:1781 > > page last free pid 54 tgid 54 stack trace: > > reset_page_owner include/linux/page_owner.h:25 [inline] > > free_pages_prepare mm/page_alloc.c:1127 [inline] > > free_unref_page+0x714/0x10c0 mm/page_alloc.c:2657 > > vfree+0x17e/0x890 mm/vmalloc.c:3382 > > delayed_vfree_work+0x57/0x70 mm/vmalloc.c:3303 > > process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229 > > process_scheduled_works kernel/workqueue.c:3310 [inline] > > worker_thread+0x677/0xe90 kernel/workqueue.c:3391 > > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > Memory state around the buggy address: > > ffff888027873f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > > ffff888027873f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > > >ffff888027874000: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > > ^ > > ffff888027874080: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc > > ffff888027874100: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc > > ================================================================== > > We also find a similar bug report in function zswap_store(), listed as below: > > > > ================================================================== > > BUG: KASAN: slab-use-after-free in zswap_compress mm/zswap.c:925 [inline] > > BUG: KASAN: slab-use-after-free in zswap_store_page mm/zswap.c:1426 [inline] > > BUG: KASAN: slab-use-after-free in zswap_store+0x2307/0x25e0 mm/zswap.c:1533 > > Read of size 4 at addr ffff8880219f6b44 by task kswapd0/88 > > > > CPU: 1 UID: 0 PID: 88 Comm: kswapd0 Tainted: G U > > 6.12.0-09435-g2c22dc1ee3a1 #11 > > Tainted: [U]=USER > > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > > rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014 > > Call Trace: > > <TASK> > > __dump_stack lib/dump_stack.c:94 [inline] > > dump_stack_lvl+0x116/0x1b0 lib/dump_stack.c:120 > > print_address_description mm/kasan/report.c:378 [inline] > > print_report+0xc0/0x5e0 mm/kasan/report.c:489 > > kasan_report+0xbd/0xf0 mm/kasan/report.c:602 > > zswap_compress mm/zswap.c:925 [inline] > > zswap_store_page mm/zswap.c:1426 [inline] > > zswap_store+0x2307/0x25e0 mm/zswap.c:1533 > > swap_writepage+0x3a8/0xe50 mm/page_io.c:279 > > pageout+0x3b9/0xa90 mm/vmscan.c:689 > > shrink_folio_list+0x2988/0x4340 mm/vmscan.c:1367 > > evict_folios+0x72b/0x1a10 mm/vmscan.c:4593 > > try_to_shrink_lruvec+0x62b/0xa60 mm/vmscan.c:4789 > > shrink_one+0x417/0x7c0 mm/vmscan.c:4834 > > shrink_many mm/vmscan.c:4897 [inline] > > lru_gen_shrink_node mm/vmscan.c:4975 [inline] > > shrink_node+0x269a/0x3d60 mm/vmscan.c:5956 > > kswapd_shrink_node mm/vmscan.c:6785 [inline] > > balance_pgdat+0xbe5/0x18c0 mm/vmscan.c:6977 > > kswapd+0x6ff/0xd60 mm/vmscan.c:7246 > > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > </TASK> > > > > Allocated by task 1: > > kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 > > kasan_save_track+0x14/0x30 mm/kasan/common.c:68 > > poison_kmalloc_redzone mm/kasan/common.c:377 [inline] > > __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 > > kasan_kmalloc include/linux/kasan.h:260 [inline] > > __do_kmalloc_node mm/slub.c:4283 [inline] > > __kmalloc_noprof+0x212/0x530 mm/slub.c:4295 > > kmalloc_noprof include/linux/slab.h:905 [inline] > > kzalloc_noprof include/linux/slab.h:1037 [inline] > > __acomp_request_alloc_noprof include/crypto/internal/acompress.h:75 [inline] > > acomp_request_alloc+0x46/0x110 crypto/acompress.c:131 > > zswap_cpu_comp_prepare+0x1f4/0x470 mm/zswap.c:840 > > cpuhp_invoke_callback+0x26d/0x9d0 kernel/cpu.c:204 > > cpuhp_issue_call+0x1c1/0x8d0 kernel/cpu.c:2375 > > __cpuhp_state_add_instance_cpuslocked+0x26a/0x3c0 kernel/cpu.c:2437 > > __cpuhp_state_add_instance+0xd7/0x2e0 kernel/cpu.c:2458 > > cpuhp_state_add_instance include/linux/cpuhotplug.h:386 [inline] > > zswap_pool_create+0x2c3/0x5c0 mm/zswap.c:288 > > __zswap_pool_create_fallback mm/zswap.c:356 [inline] > > zswap_setup+0x3a5/0x820 mm/zswap.c:1781 > > zswap_init+0x2d/0x40 mm/zswap.c:1817 > > do_one_initcall+0x111/0x6d0 init/main.c:1266 > > do_initcall_level init/main.c:1328 [inline] > > do_initcalls init/main.c:1344 [inline] > > do_basic_setup init/main.c:1363 [inline] > > kernel_init_freeable+0x5ae/0x8a0 init/main.c:1577 > > kernel_init+0x1e/0x2d0 init/main.c:1466 > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > Freed by task 901: > > kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 > > kasan_save_track+0x14/0x30 mm/kasan/common.c:68 > > kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:582 > > poison_slab_object mm/kasan/common.c:247 [inline] > > __kasan_slab_free+0x54/0x70 mm/kasan/common.c:264 > > kasan_slab_free include/linux/kasan.h:233 [inline] > > slab_free_hook mm/slub.c:2338 [inline] > > slab_free mm/slub.c:4598 [inline] > > kfree+0x14e/0x4d0 mm/slub.c:4746 > > zswap_cpu_comp_dead+0xe3/0x1c0 mm/zswap.c:874 > > cpuhp_invoke_callback+0x564/0x9d0 kernel/cpu.c:216 > > __cpuhp_invoke_callback_range+0x104/0x220 kernel/cpu.c:965 > > cpuhp_invoke_callback_range kernel/cpu.c:989 [inline] > > cpuhp_down_callbacks kernel/cpu.c:1382 [inline] > > _cpu_down+0x41d/0xef0 kernel/cpu.c:1443 > > __cpu_down_maps_locked+0x6f/0x90 kernel/cpu.c:1473 > > work_for_cpu_fn+0x55/0xa0 kernel/workqueue.c:6719 > > process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229 > > process_scheduled_works kernel/workqueue.c:3310 [inline] > > worker_thread+0x677/0xe90 kernel/workqueue.c:3391 > > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > The buggy address belongs to the object at ffff8880219f6b00 > > which belongs to the cache kmalloc-96 of size 96 > > The buggy address is located 68 bytes inside of > > freed 96-byte region [ffff8880219f6b00, ffff8880219f6b60) > > > > The buggy address belongs to the physical page: > > page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x219f6 > > anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) > > page_type: f5(slab) > > raw: 00fff00000000000 ffff88801b041280 ffffea0000887d00 dead000000000005 > > raw: 0000000000000000 0000000000200020 00000001f5000000 0000000000000000 > > page dumped because: kasan: bad access detected > > page_owner tracks the page as allocated > > page last allocated via order 0, migratetype Unmovable, gfp_mask > > 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid > > 1 (swapper/0), ts 15792736110, free_ts 14433067061 > > set_page_owner include/linux/page_owner.h:32 [inline] > > post_alloc_hook+0x2e7/0x350 mm/page_alloc.c:1556 > > prep_new_page mm/page_alloc.c:1564 [inline] > > get_page_from_freelist+0xe4e/0x2b20 mm/page_alloc.c:3474 > > __alloc_pages_noprof+0x219/0x21f0 mm/page_alloc.c:4751 > > alloc_pages_mpol_noprof+0x2b6/0x600 mm/mempolicy.c:2265 > > alloc_slab_page mm/slub.c:2408 [inline] > > allocate_slab mm/slub.c:2574 [inline] > > new_slab+0x2d5/0x420 mm/slub.c:2627 > > ___slab_alloc+0xbb7/0x1850 mm/slub.c:3815 > > __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3905 > > __slab_alloc_node mm/slub.c:3980 [inline] > > slab_alloc_node mm/slub.c:4141 [inline] > > __kmalloc_cache_noprof+0x280/0x410 mm/slub.c:4309 > > kmalloc_noprof include/linux/slab.h:901 [inline] > > kzalloc_noprof include/linux/slab.h:1037 [inline] > > usb_hub_create_port_device+0xbb/0xde0 drivers/usb/core/port.c:743 > > hub_configure drivers/usb/core/hub.c:1710 [inline] > > hub_probe+0x1ceb/0x2fc0 drivers/usb/core/hub.c:1965 > > usb_probe_interface+0x314/0x9f0 drivers/usb/core/driver.c:399 > > call_driver_probe drivers/base/dd.c:579 [inline] > > really_probe+0x252/0xa90 drivers/base/dd.c:658 > > __driver_probe_device+0x1df/0x450 drivers/base/dd.c:800 > > driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:830 > > __device_attach_driver+0x1db/0x2f0 drivers/base/dd.c:958 > > bus_for_each_drv+0x14c/0x1d0 drivers/base/bus.c:459 > > page last free pid 25 tgid 25 stack trace: > > reset_page_owner include/linux/page_owner.h:25 [inline] > > free_pages_prepare mm/page_alloc.c:1127 [inline] > > free_unref_page+0x714/0x10c0 mm/page_alloc.c:2657 > > vfree+0x17e/0x890 mm/vmalloc.c:3382 > > delayed_vfree_work+0x57/0x70 mm/vmalloc.c:3303 > > process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229 > > process_scheduled_works kernel/workqueue.c:3310 [inline] > > worker_thread+0x677/0xe90 kernel/workqueue.c:3391 > > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > Memory state around the buggy address: > > ffff8880219f6a00: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc > > ffff8880219f6a80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc > > >ffff8880219f6b00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > > ^ > > ffff8880219f6b80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc > > ffff8880219f6c00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > > ================================================================== > > If you have any questions, please contact us. > > > > Best Regards, > > Yue [-- Attachment #2: 0001-mm-zswap-fix-race-between-de-compression-and-CPU-hot.patch --] [-- Type: application/octet-stream, Size: 2948 bytes --] From 6bacd9bccf9d2e8b2de9a2e574243a6523b1b205 Mon Sep 17 00:00:00 2001 From: Yosry Ahmed <yosryahmed@google.com> Date: Tue, 17 Dec 2024 19:17:06 +0000 Subject: [PATCH] mm: zswap: fix race between [de]compression and CPU hotunplug In zswap_compress() and zswap_decompress(), the per-CPU acomp_ctx of the current CPU at the beginning of the operation is used. However, since neither preemption nor migration are disabled, it is possible that the operation continues on a different CPU. If the original CPU is hotunplugged while the acomp_ctx is still in use, we run into a UAF bug. There are a few ways to fix this: (a) Add a refcount for acomp_ctx. (b) Disable migration while using the per-CPU acomp_ctx. (c) Disable CPU hotunplug while using the per-CPU acomp_ctx. Implement (c) since it's simpler than (a), and (b) involves using migrate_disable() which is apparently discouraged. Reported-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Sam Sun <samsun1006219@gmail.com> Signed-off-by: Yosry Ahmed <yosryahmed@google.com> --- mm/zswap.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) diff --git a/mm/zswap.c b/mm/zswap.c index 0030ce8fecfc5..0f57c98fcb135 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -875,6 +875,21 @@ static int zswap_cpu_comp_dead(unsigned int cpu, struct hlist_node *node) return 0; } +static struct crypto_acomp_ctx *acomp_ctx_get_cpu(struct crypto_acomp_ctx __percpu *acomp_ctx) +{ + /* + * Prevent CPU hotplug from freeing this CPU's acomp_ctx until + * acomp_ctx_put_cpu(). + */ + cpus_read_lock(); + return raw_cpu_ptr(acomp_ctx); +} + +static void acomp_ctx_put_cpu(void) +{ + cpus_read_unlock(); +} + static bool zswap_compress(struct folio *folio, struct zswap_entry *entry) { struct crypto_acomp_ctx *acomp_ctx; @@ -887,8 +902,7 @@ static bool zswap_compress(struct folio *folio, struct zswap_entry *entry) gfp_t gfp; u8 *dst; - acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); - + acomp_ctx = acomp_ctx_get_cpu(entry->pool->acomp_ctx); mutex_lock(&acomp_ctx->mutex); dst = acomp_ctx->buffer; @@ -944,6 +958,7 @@ static bool zswap_compress(struct folio *folio, struct zswap_entry *entry) zswap_reject_alloc_fail++; mutex_unlock(&acomp_ctx->mutex); + acomp_ctx_put_cpu(); return comp_ret == 0 && alloc_ret == 0; } @@ -954,7 +969,7 @@ static void zswap_decompress(struct zswap_entry *entry, struct folio *folio) struct crypto_acomp_ctx *acomp_ctx; u8 *src; - acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); + acomp_ctx = acomp_ctx_get_cpu(entry->pool->acomp_ctx); mutex_lock(&acomp_ctx->mutex); src = zpool_map_handle(zpool, entry->handle, ZPOOL_MM_RO); @@ -984,6 +999,7 @@ static void zswap_decompress(struct zswap_entry *entry, struct folio *folio) if (src != acomp_ctx->buffer) zpool_unmap_handle(zpool, entry->handle); + acomp_ctx_put_cpu(); } /********************************* -- 2.47.1.613.gc27f4b7a9f-goog ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Bug] KASAN: slab-use-after-free Read in zswap_decompress 2024-12-17 19:32 ` Yosry Ahmed @ 2024-12-18 9:17 ` Sam Sun 2024-12-19 21:04 ` Yosry Ahmed 0 siblings, 1 reply; 5+ messages in thread From: Sam Sun @ 2024-12-18 9:17 UTC (permalink / raw) To: Yosry Ahmed Cc: linux-kernel, linux-mm, syzkaller-bugs, akpm, chengming.zhou, Nhat Pham, hannes On Wed, Dec 18, 2024 at 3:32 AM Yosry Ahmed <yosryahmed@google.com> wrote: > > On Tue, Dec 17, 2024 at 8:30 AM Yosry Ahmed <yosryahmed@google.com> wrote: > > > > On Tue, Dec 17, 2024 at 2:52 AM Sam Sun <samsun1006219@gmail.com> wrote: > > > > > > Dear developers and maintainers, > > > > > > We encountered a slab-use-after-free bug while using our modified > > > syzkaller. Kernel crash log is listed below. > > > > > > Thanks for reporting this! > > > > This seems to be the problem that Johannes pointed out in: > > https://lore.kernel.org/lkml/20241113213007.GB1564047@cmpxchg.org/. > > > > Would you be able to check if the following diff fixes the problem? > > I sent a poached semi-staged git diff, apologies. Please try the > proper patch attached instead. > I am sorry that I don't have a PoC that can trigger this bug. But according to your analysis, I think this patch can fix the bug properly. > > > > > diff --git a/mm/zswap.c b/mm/zswap.c > > index 0030ce8fecfc5..089d70dee3246 100644 > > --- a/mm/zswap.c > > +++ b/mm/zswap.c > > @@ -875,6 +875,21 @@ static int zswap_cpu_comp_dead(unsigned int cpu, > > struct hlist_node *node) > > return 0; > > } > > > > +static void acomp_ctx_get_cpu(struct crypto_acomp_ctx *acomp_ctx) > > +{ > > + /* > > + * Prevent CPU hotplug from freeing this CPU's acomp_ctx until > > + * acomp_ctx_put_cpu(). > > + */ > > + cpus_read_lock(); > > + return raw_cpu_ptr > > +} > > + > > +static void acomp_ctx_put_cpu(void) > > +{ > > + cpus_read_unlock(); > > +} > > + > > static bool zswap_compress(struct folio *folio, struct zswap_entry *entry) > > { > > struct crypto_acomp_ctx *acomp_ctx; > > @@ -887,8 +902,7 @@ static bool zswap_compress(struct folio *folio, > > struct zswap_entry *entry) > > gfp_t gfp; > > u8 *dst; > > > > - acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); > > - > > + acomp_ctx = acomp_ctx_get_cpu(entry->pool->acomp_ctx); > > mutex_lock(&acomp_ctx->mutex); > > > > dst = acomp_ctx->buffer; > > @@ -944,6 +958,7 @@ static bool zswap_compress(struct folio *folio, > > struct zswap_entry *entry) > > zswap_reject_alloc_fail++; > > > > mutex_unlock(&acomp_ctx->mutex); > > + acomp_ctx_put_cpu(); > > return comp_ret == 0 && alloc_ret == 0; > > } > > > > @@ -954,7 +969,7 @@ static void zswap_decompress(struct zswap_entry > > *entry, struct folio *folio) > > struct crypto_acomp_ctx *acomp_ctx; > > u8 *src; > > > > - acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); > > + acomp_ctx = acompx_ctx_get_cpu(entry->pool->acomp_ctx); > > mutex_lock(&acomp_ctx->mutex); > > > > src = zpool_map_handle(zpool, entry->handle, ZPOOL_MM_RO); > > @@ -984,6 +999,7 @@ static void zswap_decompress(struct zswap_entry > > *entry, struct folio *folio) > > > > if (src != acomp_ctx->buffer) > > zpool_unmap_handle(zpool, entry->handle); > > + acomp_ctx_put_cpu(); > > } > > > > /********************************* > > > > > > > > > > > > > ================================================================== > > > BUG: KASAN: slab-use-after-free in zswap_decompress+0x7d7/0x810 mm/zswap.c:988 > > > Read of size 4 at addr ffff888027874044 by task kswapd0/92 > > > > > > CPU: 1 UID: 0 PID: 92 Comm: kswapd0 Not tainted 6.12.0-09435-g2c22dc1ee3a1 #11 > > > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > > > rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014 > > > Call Trace: > > > <TASK> > > > __dump_stack lib/dump_stack.c:94 [inline] > > > dump_stack_lvl+0x116/0x1b0 lib/dump_stack.c:120 > > > print_address_description mm/kasan/report.c:378 [inline] > > > print_report+0xc0/0x5e0 mm/kasan/report.c:489 > > > kasan_report+0xbd/0xf0 mm/kasan/report.c:602 > > > zswap_decompress+0x7d7/0x810 mm/zswap.c:988 > > > zswap_writeback_entry+0x1e9/0x860 mm/zswap.c:1058 > > > shrink_memcg_cb+0x213/0x360 mm/zswap.c:1163 > > > __list_lru_walk_one+0x15e/0x490 mm/list_lru.c:301 > > > list_lru_walk_one+0x3e/0x50 mm/list_lru.c:338 > > > list_lru_shrink_walk include/linux/list_lru.h:240 [inline] > > > zswap_shrinker_scan+0x135/0x220 mm/zswap.c:1197 > > > do_shrink_slab+0x44e/0x1190 mm/shrinker.c:437 > > > shrink_slab_memcg mm/shrinker.c:550 [inline] > > > shrink_slab+0xb61/0x12a0 mm/shrinker.c:628 > > > shrink_one+0x4ad/0x7c0 mm/vmscan.c:4836 > > > shrink_many mm/vmscan.c:4897 [inline] > > > lru_gen_shrink_node mm/vmscan.c:4975 [inline] > > > shrink_node+0x269a/0x3d60 mm/vmscan.c:5956 > > > kswapd_shrink_node mm/vmscan.c:6785 [inline] > > > balance_pgdat+0xbe5/0x18c0 mm/vmscan.c:6977 > > > kswapd+0x6ff/0xd60 mm/vmscan.c:7246 > > > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > </TASK> > > > > > > Allocated by task 1: > > > kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 > > > kasan_save_track+0x14/0x30 mm/kasan/common.c:68 > > > poison_kmalloc_redzone mm/kasan/common.c:377 [inline] > > > __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 > > > kasan_kmalloc include/linux/kasan.h:260 [inline] > > > __do_kmalloc_node mm/slub.c:4283 [inline] > > > __kmalloc_noprof+0x212/0x530 mm/slub.c:4295 > > > kmalloc_noprof include/linux/slab.h:905 [inline] > > > kzalloc_noprof include/linux/slab.h:1037 [inline] > > > __acomp_request_alloc_noprof include/crypto/internal/acompress.h:75 [inline] > > > acomp_request_alloc+0x46/0x110 crypto/acompress.c:131 > > > zswap_cpu_comp_prepare+0x1f4/0x470 mm/zswap.c:840 > > > cpuhp_invoke_callback+0x26d/0x9d0 kernel/cpu.c:204 > > > cpuhp_issue_call+0x1c1/0x8d0 kernel/cpu.c:2375 > > > __cpuhp_state_add_instance_cpuslocked+0x26a/0x3c0 kernel/cpu.c:2437 > > > __cpuhp_state_add_instance+0xd7/0x2e0 kernel/cpu.c:2458 > > > cpuhp_state_add_instance include/linux/cpuhotplug.h:386 [inline] > > > zswap_pool_create+0x2c3/0x5c0 mm/zswap.c:288 > > > __zswap_pool_create_fallback mm/zswap.c:356 [inline] > > > zswap_setup+0x3a5/0x820 mm/zswap.c:1781 > > > zswap_init+0x2d/0x40 mm/zswap.c:1817 > > > do_one_initcall+0x111/0x6d0 init/main.c:1266 > > > do_initcall_level init/main.c:1328 [inline] > > > do_initcalls init/main.c:1344 [inline] > > > do_basic_setup init/main.c:1363 [inline] > > > kernel_init_freeable+0x5ae/0x8a0 init/main.c:1577 > > > kernel_init+0x1e/0x2d0 init/main.c:1466 > > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > > > Freed by task 25: > > > kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 > > > kasan_save_track+0x14/0x30 mm/kasan/common.c:68 > > > kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:582 > > > poison_slab_object mm/kasan/common.c:247 [inline] > > > __kasan_slab_free+0x54/0x70 mm/kasan/common.c:264 > > > kasan_slab_free include/linux/kasan.h:233 [inline] > > > slab_free_hook mm/slub.c:2338 [inline] > > > slab_free mm/slub.c:4598 [inline] > > > kfree+0x14e/0x4d0 mm/slub.c:4746 > > > zswap_cpu_comp_dead+0xe3/0x1c0 mm/zswap.c:874 > > > cpuhp_invoke_callback+0x564/0x9d0 kernel/cpu.c:216 > > > __cpuhp_invoke_callback_range+0x104/0x220 kernel/cpu.c:965 > > > cpuhp_invoke_callback_range kernel/cpu.c:989 [inline] > > > cpuhp_down_callbacks kernel/cpu.c:1382 [inline] > > > _cpu_down+0x41d/0xef0 kernel/cpu.c:1443 > > > __cpu_down_maps_locked+0x6f/0x90 kernel/cpu.c:1473 > > > work_for_cpu_fn+0x55/0xa0 kernel/workqueue.c:6719 > > > process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229 > > > process_scheduled_works kernel/workqueue.c:3310 [inline] > > > worker_thread+0x677/0xe90 kernel/workqueue.c:3391 > > > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > > > The buggy address belongs to the object at ffff888027874000 > > > which belongs to the cache kmalloc-96 of size 96 > > > The buggy address is located 68 bytes inside of > > > freed 96-byte region [ffff888027874000, ffff888027874060) > > > > > > The buggy address belongs to the physical page: > > > page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x27874 > > > flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) > > > page_type: f5(slab) > > > raw: 00fff00000000000 ffff88801b041280 dead000000000100 dead000000000122 > > > raw: 0000000000000000 0000000000200020 00000001f5000000 0000000000000000 > > > page dumped because: kasan: bad access detected > > > page_owner tracks the page as allocated > > > page last allocated via order 0, migratetype Unmovable, gfp_mask > > > 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid > > > 1 (swapper/0), ts 20389586985, free_ts 18720773637 > > > set_page_owner include/linux/page_owner.h:32 [inline] > > > post_alloc_hook+0x2e7/0x350 mm/page_alloc.c:1556 > > > prep_new_page mm/page_alloc.c:1564 [inline] > > > get_page_from_freelist+0xe4e/0x2b20 mm/page_alloc.c:3474 > > > __alloc_pages_noprof+0x219/0x21f0 mm/page_alloc.c:4751 > > > alloc_pages_mpol_noprof+0x2b6/0x600 mm/mempolicy.c:2265 > > > alloc_slab_page mm/slub.c:2408 [inline] > > > allocate_slab mm/slub.c:2574 [inline] > > > new_slab+0x2d5/0x420 mm/slub.c:2627 > > > ___slab_alloc+0xbb7/0x1850 mm/slub.c:3815 > > > __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3905 > > > __slab_alloc_node mm/slub.c:3980 [inline] > > > slab_alloc_node mm/slub.c:4141 [inline] > > > __do_kmalloc_node mm/slub.c:4282 [inline] > > > __kmalloc_noprof+0x2ac/0x530 mm/slub.c:4295 > > > kmalloc_noprof include/linux/slab.h:905 [inline] > > > kzalloc_noprof include/linux/slab.h:1037 [inline] > > > __acomp_request_alloc_noprof include/crypto/internal/acompress.h:75 [inline] > > > acomp_request_alloc+0x46/0x110 crypto/acompress.c:131 > > > zswap_cpu_comp_prepare+0x1f4/0x470 mm/zswap.c:840 > > > cpuhp_invoke_callback+0x26d/0x9d0 kernel/cpu.c:204 > > > cpuhp_issue_call+0x1c1/0x8d0 kernel/cpu.c:2375 > > > __cpuhp_state_add_instance_cpuslocked+0x26a/0x3c0 kernel/cpu.c:2437 > > > __cpuhp_state_add_instance+0xd7/0x2e0 kernel/cpu.c:2458 > > > cpuhp_state_add_instance include/linux/cpuhotplug.h:386 [inline] > > > zswap_pool_create+0x2c3/0x5c0 mm/zswap.c:288 > > > __zswap_pool_create_fallback mm/zswap.c:356 [inline] > > > zswap_setup+0x3a5/0x820 mm/zswap.c:1781 > > > page last free pid 54 tgid 54 stack trace: > > > reset_page_owner include/linux/page_owner.h:25 [inline] > > > free_pages_prepare mm/page_alloc.c:1127 [inline] > > > free_unref_page+0x714/0x10c0 mm/page_alloc.c:2657 > > > vfree+0x17e/0x890 mm/vmalloc.c:3382 > > > delayed_vfree_work+0x57/0x70 mm/vmalloc.c:3303 > > > process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229 > > > process_scheduled_works kernel/workqueue.c:3310 [inline] > > > worker_thread+0x677/0xe90 kernel/workqueue.c:3391 > > > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > > > Memory state around the buggy address: > > > ffff888027873f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > > > ffff888027873f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > > > >ffff888027874000: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > > > ^ > > > ffff888027874080: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc > > > ffff888027874100: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc > > > ================================================================== > > > We also find a similar bug report in function zswap_store(), listed as below: > > > > > > ================================================================== > > > BUG: KASAN: slab-use-after-free in zswap_compress mm/zswap.c:925 [inline] > > > BUG: KASAN: slab-use-after-free in zswap_store_page mm/zswap.c:1426 [inline] > > > BUG: KASAN: slab-use-after-free in zswap_store+0x2307/0x25e0 mm/zswap.c:1533 > > > Read of size 4 at addr ffff8880219f6b44 by task kswapd0/88 > > > > > > CPU: 1 UID: 0 PID: 88 Comm: kswapd0 Tainted: G U > > > 6.12.0-09435-g2c22dc1ee3a1 #11 > > > Tainted: [U]=USER > > > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > > > rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014 > > > Call Trace: > > > <TASK> > > > __dump_stack lib/dump_stack.c:94 [inline] > > > dump_stack_lvl+0x116/0x1b0 lib/dump_stack.c:120 > > > print_address_description mm/kasan/report.c:378 [inline] > > > print_report+0xc0/0x5e0 mm/kasan/report.c:489 > > > kasan_report+0xbd/0xf0 mm/kasan/report.c:602 > > > zswap_compress mm/zswap.c:925 [inline] > > > zswap_store_page mm/zswap.c:1426 [inline] > > > zswap_store+0x2307/0x25e0 mm/zswap.c:1533 > > > swap_writepage+0x3a8/0xe50 mm/page_io.c:279 > > > pageout+0x3b9/0xa90 mm/vmscan.c:689 > > > shrink_folio_list+0x2988/0x4340 mm/vmscan.c:1367 > > > evict_folios+0x72b/0x1a10 mm/vmscan.c:4593 > > > try_to_shrink_lruvec+0x62b/0xa60 mm/vmscan.c:4789 > > > shrink_one+0x417/0x7c0 mm/vmscan.c:4834 > > > shrink_many mm/vmscan.c:4897 [inline] > > > lru_gen_shrink_node mm/vmscan.c:4975 [inline] > > > shrink_node+0x269a/0x3d60 mm/vmscan.c:5956 > > > kswapd_shrink_node mm/vmscan.c:6785 [inline] > > > balance_pgdat+0xbe5/0x18c0 mm/vmscan.c:6977 > > > kswapd+0x6ff/0xd60 mm/vmscan.c:7246 > > > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > </TASK> > > > > > > Allocated by task 1: > > > kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 > > > kasan_save_track+0x14/0x30 mm/kasan/common.c:68 > > > poison_kmalloc_redzone mm/kasan/common.c:377 [inline] > > > __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 > > > kasan_kmalloc include/linux/kasan.h:260 [inline] > > > __do_kmalloc_node mm/slub.c:4283 [inline] > > > __kmalloc_noprof+0x212/0x530 mm/slub.c:4295 > > > kmalloc_noprof include/linux/slab.h:905 [inline] > > > kzalloc_noprof include/linux/slab.h:1037 [inline] > > > __acomp_request_alloc_noprof include/crypto/internal/acompress.h:75 [inline] > > > acomp_request_alloc+0x46/0x110 crypto/acompress.c:131 > > > zswap_cpu_comp_prepare+0x1f4/0x470 mm/zswap.c:840 > > > cpuhp_invoke_callback+0x26d/0x9d0 kernel/cpu.c:204 > > > cpuhp_issue_call+0x1c1/0x8d0 kernel/cpu.c:2375 > > > __cpuhp_state_add_instance_cpuslocked+0x26a/0x3c0 kernel/cpu.c:2437 > > > __cpuhp_state_add_instance+0xd7/0x2e0 kernel/cpu.c:2458 > > > cpuhp_state_add_instance include/linux/cpuhotplug.h:386 [inline] > > > zswap_pool_create+0x2c3/0x5c0 mm/zswap.c:288 > > > __zswap_pool_create_fallback mm/zswap.c:356 [inline] > > > zswap_setup+0x3a5/0x820 mm/zswap.c:1781 > > > zswap_init+0x2d/0x40 mm/zswap.c:1817 > > > do_one_initcall+0x111/0x6d0 init/main.c:1266 > > > do_initcall_level init/main.c:1328 [inline] > > > do_initcalls init/main.c:1344 [inline] > > > do_basic_setup init/main.c:1363 [inline] > > > kernel_init_freeable+0x5ae/0x8a0 init/main.c:1577 > > > kernel_init+0x1e/0x2d0 init/main.c:1466 > > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > > > Freed by task 901: > > > kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 > > > kasan_save_track+0x14/0x30 mm/kasan/common.c:68 > > > kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:582 > > > poison_slab_object mm/kasan/common.c:247 [inline] > > > __kasan_slab_free+0x54/0x70 mm/kasan/common.c:264 > > > kasan_slab_free include/linux/kasan.h:233 [inline] > > > slab_free_hook mm/slub.c:2338 [inline] > > > slab_free mm/slub.c:4598 [inline] > > > kfree+0x14e/0x4d0 mm/slub.c:4746 > > > zswap_cpu_comp_dead+0xe3/0x1c0 mm/zswap.c:874 > > > cpuhp_invoke_callback+0x564/0x9d0 kernel/cpu.c:216 > > > __cpuhp_invoke_callback_range+0x104/0x220 kernel/cpu.c:965 > > > cpuhp_invoke_callback_range kernel/cpu.c:989 [inline] > > > cpuhp_down_callbacks kernel/cpu.c:1382 [inline] > > > _cpu_down+0x41d/0xef0 kernel/cpu.c:1443 > > > __cpu_down_maps_locked+0x6f/0x90 kernel/cpu.c:1473 > > > work_for_cpu_fn+0x55/0xa0 kernel/workqueue.c:6719 > > > process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229 > > > process_scheduled_works kernel/workqueue.c:3310 [inline] > > > worker_thread+0x677/0xe90 kernel/workqueue.c:3391 > > > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > > > The buggy address belongs to the object at ffff8880219f6b00 > > > which belongs to the cache kmalloc-96 of size 96 > > > The buggy address is located 68 bytes inside of > > > freed 96-byte region [ffff8880219f6b00, ffff8880219f6b60) > > > > > > The buggy address belongs to the physical page: > > > page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x219f6 > > > anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) > > > page_type: f5(slab) > > > raw: 00fff00000000000 ffff88801b041280 ffffea0000887d00 dead000000000005 > > > raw: 0000000000000000 0000000000200020 00000001f5000000 0000000000000000 > > > page dumped because: kasan: bad access detected > > > page_owner tracks the page as allocated > > > page last allocated via order 0, migratetype Unmovable, gfp_mask > > > 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid > > > 1 (swapper/0), ts 15792736110, free_ts 14433067061 > > > set_page_owner include/linux/page_owner.h:32 [inline] > > > post_alloc_hook+0x2e7/0x350 mm/page_alloc.c:1556 > > > prep_new_page mm/page_alloc.c:1564 [inline] > > > get_page_from_freelist+0xe4e/0x2b20 mm/page_alloc.c:3474 > > > __alloc_pages_noprof+0x219/0x21f0 mm/page_alloc.c:4751 > > > alloc_pages_mpol_noprof+0x2b6/0x600 mm/mempolicy.c:2265 > > > alloc_slab_page mm/slub.c:2408 [inline] > > > allocate_slab mm/slub.c:2574 [inline] > > > new_slab+0x2d5/0x420 mm/slub.c:2627 > > > ___slab_alloc+0xbb7/0x1850 mm/slub.c:3815 > > > __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3905 > > > __slab_alloc_node mm/slub.c:3980 [inline] > > > slab_alloc_node mm/slub.c:4141 [inline] > > > __kmalloc_cache_noprof+0x280/0x410 mm/slub.c:4309 > > > kmalloc_noprof include/linux/slab.h:901 [inline] > > > kzalloc_noprof include/linux/slab.h:1037 [inline] > > > usb_hub_create_port_device+0xbb/0xde0 drivers/usb/core/port.c:743 > > > hub_configure drivers/usb/core/hub.c:1710 [inline] > > > hub_probe+0x1ceb/0x2fc0 drivers/usb/core/hub.c:1965 > > > usb_probe_interface+0x314/0x9f0 drivers/usb/core/driver.c:399 > > > call_driver_probe drivers/base/dd.c:579 [inline] > > > really_probe+0x252/0xa90 drivers/base/dd.c:658 > > > __driver_probe_device+0x1df/0x450 drivers/base/dd.c:800 > > > driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:830 > > > __device_attach_driver+0x1db/0x2f0 drivers/base/dd.c:958 > > > bus_for_each_drv+0x14c/0x1d0 drivers/base/bus.c:459 > > > page last free pid 25 tgid 25 stack trace: > > > reset_page_owner include/linux/page_owner.h:25 [inline] > > > free_pages_prepare mm/page_alloc.c:1127 [inline] > > > free_unref_page+0x714/0x10c0 mm/page_alloc.c:2657 > > > vfree+0x17e/0x890 mm/vmalloc.c:3382 > > > delayed_vfree_work+0x57/0x70 mm/vmalloc.c:3303 > > > process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229 > > > process_scheduled_works kernel/workqueue.c:3310 [inline] > > > worker_thread+0x677/0xe90 kernel/workqueue.c:3391 > > > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > > > Memory state around the buggy address: > > > ffff8880219f6a00: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc > > > ffff8880219f6a80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc > > > >ffff8880219f6b00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > > > ^ > > > ffff8880219f6b80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc > > > ffff8880219f6c00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > > > ================================================================== > > > If you have any questions, please contact us. > > > > > > Best Regards, > > > Yue ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Bug] KASAN: slab-use-after-free Read in zswap_decompress 2024-12-18 9:17 ` Sam Sun @ 2024-12-19 21:04 ` Yosry Ahmed 0 siblings, 0 replies; 5+ messages in thread From: Yosry Ahmed @ 2024-12-19 21:04 UTC (permalink / raw) To: Sam Sun Cc: linux-kernel, linux-mm, syzkaller-bugs, akpm, chengming.zhou, Nhat Pham, hannes On Wed, Dec 18, 2024 at 1:17 AM Sam Sun <samsun1006219@gmail.com> wrote: > > On Wed, Dec 18, 2024 at 3:32 AM Yosry Ahmed <yosryahmed@google.com> wrote: > > > > On Tue, Dec 17, 2024 at 8:30 AM Yosry Ahmed <yosryahmed@google.com> wrote: > > > > > > On Tue, Dec 17, 2024 at 2:52 AM Sam Sun <samsun1006219@gmail.com> wrote: > > > > > > > > Dear developers and maintainers, > > > > > > > > We encountered a slab-use-after-free bug while using our modified > > > > syzkaller. Kernel crash log is listed below. > > > > > > > > > Thanks for reporting this! > > > > > > This seems to be the problem that Johannes pointed out in: > > > https://lore.kernel.org/lkml/20241113213007.GB1564047@cmpxchg.org/. > > > > > > Would you be able to check if the following diff fixes the problem? > > > > I sent a poached semi-staged git diff, apologies. Please try the > > proper patch attached instead. > > > > I am sorry that I don't have a PoC that can trigger this bug. But > according to your analysis, I think this patch can fix the bug > properly. I was able to reproduce this in a VM with a hacky diff that sets up the race condition: diff --git a/mm/zswap.c b/mm/zswap.c index f6316b66fb236..e5f7341948924 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -893,8 +893,18 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry, gfp_t gfp; u8 *dst; + set_cpus_allowed_ptr(current, cpumask_of(1)); + pr_info("zswap_compress(): running on CPU %d\n", smp_processor_id()); + acomp_ctx = raw_cpu_ptr(pool->acomp_ctx); + set_cpus_allowed_ptr(current, cpumask_of(0)); + pr_info("zswap_compress(): running on CPU %d\n", smp_processor_id()); + pr_info("zswap_compress(): sleeping\n"); + + schedule_timeout_uninterruptible(msecs_to_jiffies(10*MSEC_PER_SEC)); + pr_info("zswap_compress(): woke up on CPU %d\n", smp_processor_id()); + mutex_lock(&acomp_ctx->mutex); dst = acomp_ctx->buffer; Running a user program that invokes zswap compression, after "sleeping" is printed I manually offlined CPU 1 and I got a similar KASAN UAF splat and a kernel crash due to faulting on an illegal kernel address. This goes away with my fix and the offlining is delayed until the end of zswap_compress(), so I will send it out separately. > > > > > > > > > diff --git a/mm/zswap.c b/mm/zswap.c > > > index 0030ce8fecfc5..089d70dee3246 100644 > > > --- a/mm/zswap.c > > > +++ b/mm/zswap.c > > > @@ -875,6 +875,21 @@ static int zswap_cpu_comp_dead(unsigned int cpu, > > > struct hlist_node *node) > > > return 0; > > > } > > > > > > +static void acomp_ctx_get_cpu(struct crypto_acomp_ctx *acomp_ctx) > > > +{ > > > + /* > > > + * Prevent CPU hotplug from freeing this CPU's acomp_ctx until > > > + * acomp_ctx_put_cpu(). > > > + */ > > > + cpus_read_lock(); > > > + return raw_cpu_ptr > > > +} > > > + > > > +static void acomp_ctx_put_cpu(void) > > > +{ > > > + cpus_read_unlock(); > > > +} > > > + > > > static bool zswap_compress(struct folio *folio, struct zswap_entry *entry) > > > { > > > struct crypto_acomp_ctx *acomp_ctx; > > > @@ -887,8 +902,7 @@ static bool zswap_compress(struct folio *folio, > > > struct zswap_entry *entry) > > > gfp_t gfp; > > > u8 *dst; > > > > > > - acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); > > > - > > > + acomp_ctx = acomp_ctx_get_cpu(entry->pool->acomp_ctx); > > > mutex_lock(&acomp_ctx->mutex); > > > > > > dst = acomp_ctx->buffer; > > > @@ -944,6 +958,7 @@ static bool zswap_compress(struct folio *folio, > > > struct zswap_entry *entry) > > > zswap_reject_alloc_fail++; > > > > > > mutex_unlock(&acomp_ctx->mutex); > > > + acomp_ctx_put_cpu(); > > > return comp_ret == 0 && alloc_ret == 0; > > > } > > > > > > @@ -954,7 +969,7 @@ static void zswap_decompress(struct zswap_entry > > > *entry, struct folio *folio) > > > struct crypto_acomp_ctx *acomp_ctx; > > > u8 *src; > > > > > > - acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); > > > + acomp_ctx = acompx_ctx_get_cpu(entry->pool->acomp_ctx); > > > mutex_lock(&acomp_ctx->mutex); > > > > > > src = zpool_map_handle(zpool, entry->handle, ZPOOL_MM_RO); > > > @@ -984,6 +999,7 @@ static void zswap_decompress(struct zswap_entry > > > *entry, struct folio *folio) > > > > > > if (src != acomp_ctx->buffer) > > > zpool_unmap_handle(zpool, entry->handle); > > > + acomp_ctx_put_cpu(); > > > } > > > > > > /********************************* > > > > > > > > > > > > > > > > > > ================================================================== > > > > BUG: KASAN: slab-use-after-free in zswap_decompress+0x7d7/0x810 mm/zswap.c:988 > > > > Read of size 4 at addr ffff888027874044 by task kswapd0/92 > > > > > > > > CPU: 1 UID: 0 PID: 92 Comm: kswapd0 Not tainted 6.12.0-09435-g2c22dc1ee3a1 #11 > > > > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > > > > rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014 > > > > Call Trace: > > > > <TASK> > > > > __dump_stack lib/dump_stack.c:94 [inline] > > > > dump_stack_lvl+0x116/0x1b0 lib/dump_stack.c:120 > > > > print_address_description mm/kasan/report.c:378 [inline] > > > > print_report+0xc0/0x5e0 mm/kasan/report.c:489 > > > > kasan_report+0xbd/0xf0 mm/kasan/report.c:602 > > > > zswap_decompress+0x7d7/0x810 mm/zswap.c:988 > > > > zswap_writeback_entry+0x1e9/0x860 mm/zswap.c:1058 > > > > shrink_memcg_cb+0x213/0x360 mm/zswap.c:1163 > > > > __list_lru_walk_one+0x15e/0x490 mm/list_lru.c:301 > > > > list_lru_walk_one+0x3e/0x50 mm/list_lru.c:338 > > > > list_lru_shrink_walk include/linux/list_lru.h:240 [inline] > > > > zswap_shrinker_scan+0x135/0x220 mm/zswap.c:1197 > > > > do_shrink_slab+0x44e/0x1190 mm/shrinker.c:437 > > > > shrink_slab_memcg mm/shrinker.c:550 [inline] > > > > shrink_slab+0xb61/0x12a0 mm/shrinker.c:628 > > > > shrink_one+0x4ad/0x7c0 mm/vmscan.c:4836 > > > > shrink_many mm/vmscan.c:4897 [inline] > > > > lru_gen_shrink_node mm/vmscan.c:4975 [inline] > > > > shrink_node+0x269a/0x3d60 mm/vmscan.c:5956 > > > > kswapd_shrink_node mm/vmscan.c:6785 [inline] > > > > balance_pgdat+0xbe5/0x18c0 mm/vmscan.c:6977 > > > > kswapd+0x6ff/0xd60 mm/vmscan.c:7246 > > > > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > > > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > </TASK> > > > > > > > > Allocated by task 1: > > > > kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 > > > > kasan_save_track+0x14/0x30 mm/kasan/common.c:68 > > > > poison_kmalloc_redzone mm/kasan/common.c:377 [inline] > > > > __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 > > > > kasan_kmalloc include/linux/kasan.h:260 [inline] > > > > __do_kmalloc_node mm/slub.c:4283 [inline] > > > > __kmalloc_noprof+0x212/0x530 mm/slub.c:4295 > > > > kmalloc_noprof include/linux/slab.h:905 [inline] > > > > kzalloc_noprof include/linux/slab.h:1037 [inline] > > > > __acomp_request_alloc_noprof include/crypto/internal/acompress.h:75 [inline] > > > > acomp_request_alloc+0x46/0x110 crypto/acompress.c:131 > > > > zswap_cpu_comp_prepare+0x1f4/0x470 mm/zswap.c:840 > > > > cpuhp_invoke_callback+0x26d/0x9d0 kernel/cpu.c:204 > > > > cpuhp_issue_call+0x1c1/0x8d0 kernel/cpu.c:2375 > > > > __cpuhp_state_add_instance_cpuslocked+0x26a/0x3c0 kernel/cpu.c:2437 > > > > __cpuhp_state_add_instance+0xd7/0x2e0 kernel/cpu.c:2458 > > > > cpuhp_state_add_instance include/linux/cpuhotplug.h:386 [inline] > > > > zswap_pool_create+0x2c3/0x5c0 mm/zswap.c:288 > > > > __zswap_pool_create_fallback mm/zswap.c:356 [inline] > > > > zswap_setup+0x3a5/0x820 mm/zswap.c:1781 > > > > zswap_init+0x2d/0x40 mm/zswap.c:1817 > > > > do_one_initcall+0x111/0x6d0 init/main.c:1266 > > > > do_initcall_level init/main.c:1328 [inline] > > > > do_initcalls init/main.c:1344 [inline] > > > > do_basic_setup init/main.c:1363 [inline] > > > > kernel_init_freeable+0x5ae/0x8a0 init/main.c:1577 > > > > kernel_init+0x1e/0x2d0 init/main.c:1466 > > > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > > > > > Freed by task 25: > > > > kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 > > > > kasan_save_track+0x14/0x30 mm/kasan/common.c:68 > > > > kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:582 > > > > poison_slab_object mm/kasan/common.c:247 [inline] > > > > __kasan_slab_free+0x54/0x70 mm/kasan/common.c:264 > > > > kasan_slab_free include/linux/kasan.h:233 [inline] > > > > slab_free_hook mm/slub.c:2338 [inline] > > > > slab_free mm/slub.c:4598 [inline] > > > > kfree+0x14e/0x4d0 mm/slub.c:4746 > > > > zswap_cpu_comp_dead+0xe3/0x1c0 mm/zswap.c:874 > > > > cpuhp_invoke_callback+0x564/0x9d0 kernel/cpu.c:216 > > > > __cpuhp_invoke_callback_range+0x104/0x220 kernel/cpu.c:965 > > > > cpuhp_invoke_callback_range kernel/cpu.c:989 [inline] > > > > cpuhp_down_callbacks kernel/cpu.c:1382 [inline] > > > > _cpu_down+0x41d/0xef0 kernel/cpu.c:1443 > > > > __cpu_down_maps_locked+0x6f/0x90 kernel/cpu.c:1473 > > > > work_for_cpu_fn+0x55/0xa0 kernel/workqueue.c:6719 > > > > process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229 > > > > process_scheduled_works kernel/workqueue.c:3310 [inline] > > > > worker_thread+0x677/0xe90 kernel/workqueue.c:3391 > > > > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > > > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > > > > > The buggy address belongs to the object at ffff888027874000 > > > > which belongs to the cache kmalloc-96 of size 96 > > > > The buggy address is located 68 bytes inside of > > > > freed 96-byte region [ffff888027874000, ffff888027874060) > > > > > > > > The buggy address belongs to the physical page: > > > > page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x27874 > > > > flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) > > > > page_type: f5(slab) > > > > raw: 00fff00000000000 ffff88801b041280 dead000000000100 dead000000000122 > > > > raw: 0000000000000000 0000000000200020 00000001f5000000 0000000000000000 > > > > page dumped because: kasan: bad access detected > > > > page_owner tracks the page as allocated > > > > page last allocated via order 0, migratetype Unmovable, gfp_mask > > > > 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid > > > > 1 (swapper/0), ts 20389586985, free_ts 18720773637 > > > > set_page_owner include/linux/page_owner.h:32 [inline] > > > > post_alloc_hook+0x2e7/0x350 mm/page_alloc.c:1556 > > > > prep_new_page mm/page_alloc.c:1564 [inline] > > > > get_page_from_freelist+0xe4e/0x2b20 mm/page_alloc.c:3474 > > > > __alloc_pages_noprof+0x219/0x21f0 mm/page_alloc.c:4751 > > > > alloc_pages_mpol_noprof+0x2b6/0x600 mm/mempolicy.c:2265 > > > > alloc_slab_page mm/slub.c:2408 [inline] > > > > allocate_slab mm/slub.c:2574 [inline] > > > > new_slab+0x2d5/0x420 mm/slub.c:2627 > > > > ___slab_alloc+0xbb7/0x1850 mm/slub.c:3815 > > > > __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3905 > > > > __slab_alloc_node mm/slub.c:3980 [inline] > > > > slab_alloc_node mm/slub.c:4141 [inline] > > > > __do_kmalloc_node mm/slub.c:4282 [inline] > > > > __kmalloc_noprof+0x2ac/0x530 mm/slub.c:4295 > > > > kmalloc_noprof include/linux/slab.h:905 [inline] > > > > kzalloc_noprof include/linux/slab.h:1037 [inline] > > > > __acomp_request_alloc_noprof include/crypto/internal/acompress.h:75 [inline] > > > > acomp_request_alloc+0x46/0x110 crypto/acompress.c:131 > > > > zswap_cpu_comp_prepare+0x1f4/0x470 mm/zswap.c:840 > > > > cpuhp_invoke_callback+0x26d/0x9d0 kernel/cpu.c:204 > > > > cpuhp_issue_call+0x1c1/0x8d0 kernel/cpu.c:2375 > > > > __cpuhp_state_add_instance_cpuslocked+0x26a/0x3c0 kernel/cpu.c:2437 > > > > __cpuhp_state_add_instance+0xd7/0x2e0 kernel/cpu.c:2458 > > > > cpuhp_state_add_instance include/linux/cpuhotplug.h:386 [inline] > > > > zswap_pool_create+0x2c3/0x5c0 mm/zswap.c:288 > > > > __zswap_pool_create_fallback mm/zswap.c:356 [inline] > > > > zswap_setup+0x3a5/0x820 mm/zswap.c:1781 > > > > page last free pid 54 tgid 54 stack trace: > > > > reset_page_owner include/linux/page_owner.h:25 [inline] > > > > free_pages_prepare mm/page_alloc.c:1127 [inline] > > > > free_unref_page+0x714/0x10c0 mm/page_alloc.c:2657 > > > > vfree+0x17e/0x890 mm/vmalloc.c:3382 > > > > delayed_vfree_work+0x57/0x70 mm/vmalloc.c:3303 > > > > process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229 > > > > process_scheduled_works kernel/workqueue.c:3310 [inline] > > > > worker_thread+0x677/0xe90 kernel/workqueue.c:3391 > > > > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > > > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > > > > > Memory state around the buggy address: > > > > ffff888027873f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > > > > ffff888027873f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > > > > >ffff888027874000: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > > > > ^ > > > > ffff888027874080: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc > > > > ffff888027874100: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc > > > > ================================================================== > > > > We also find a similar bug report in function zswap_store(), listed as below: > > > > > > > > ================================================================== > > > > BUG: KASAN: slab-use-after-free in zswap_compress mm/zswap.c:925 [inline] > > > > BUG: KASAN: slab-use-after-free in zswap_store_page mm/zswap.c:1426 [inline] > > > > BUG: KASAN: slab-use-after-free in zswap_store+0x2307/0x25e0 mm/zswap.c:1533 > > > > Read of size 4 at addr ffff8880219f6b44 by task kswapd0/88 > > > > > > > > CPU: 1 UID: 0 PID: 88 Comm: kswapd0 Tainted: G U > > > > 6.12.0-09435-g2c22dc1ee3a1 #11 > > > > Tainted: [U]=USER > > > > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > > > > rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014 > > > > Call Trace: > > > > <TASK> > > > > __dump_stack lib/dump_stack.c:94 [inline] > > > > dump_stack_lvl+0x116/0x1b0 lib/dump_stack.c:120 > > > > print_address_description mm/kasan/report.c:378 [inline] > > > > print_report+0xc0/0x5e0 mm/kasan/report.c:489 > > > > kasan_report+0xbd/0xf0 mm/kasan/report.c:602 > > > > zswap_compress mm/zswap.c:925 [inline] > > > > zswap_store_page mm/zswap.c:1426 [inline] > > > > zswap_store+0x2307/0x25e0 mm/zswap.c:1533 > > > > swap_writepage+0x3a8/0xe50 mm/page_io.c:279 > > > > pageout+0x3b9/0xa90 mm/vmscan.c:689 > > > > shrink_folio_list+0x2988/0x4340 mm/vmscan.c:1367 > > > > evict_folios+0x72b/0x1a10 mm/vmscan.c:4593 > > > > try_to_shrink_lruvec+0x62b/0xa60 mm/vmscan.c:4789 > > > > shrink_one+0x417/0x7c0 mm/vmscan.c:4834 > > > > shrink_many mm/vmscan.c:4897 [inline] > > > > lru_gen_shrink_node mm/vmscan.c:4975 [inline] > > > > shrink_node+0x269a/0x3d60 mm/vmscan.c:5956 > > > > kswapd_shrink_node mm/vmscan.c:6785 [inline] > > > > balance_pgdat+0xbe5/0x18c0 mm/vmscan.c:6977 > > > > kswapd+0x6ff/0xd60 mm/vmscan.c:7246 > > > > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > > > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > </TASK> > > > > > > > > Allocated by task 1: > > > > kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 > > > > kasan_save_track+0x14/0x30 mm/kasan/common.c:68 > > > > poison_kmalloc_redzone mm/kasan/common.c:377 [inline] > > > > __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 > > > > kasan_kmalloc include/linux/kasan.h:260 [inline] > > > > __do_kmalloc_node mm/slub.c:4283 [inline] > > > > __kmalloc_noprof+0x212/0x530 mm/slub.c:4295 > > > > kmalloc_noprof include/linux/slab.h:905 [inline] > > > > kzalloc_noprof include/linux/slab.h:1037 [inline] > > > > __acomp_request_alloc_noprof include/crypto/internal/acompress.h:75 [inline] > > > > acomp_request_alloc+0x46/0x110 crypto/acompress.c:131 > > > > zswap_cpu_comp_prepare+0x1f4/0x470 mm/zswap.c:840 > > > > cpuhp_invoke_callback+0x26d/0x9d0 kernel/cpu.c:204 > > > > cpuhp_issue_call+0x1c1/0x8d0 kernel/cpu.c:2375 > > > > __cpuhp_state_add_instance_cpuslocked+0x26a/0x3c0 kernel/cpu.c:2437 > > > > __cpuhp_state_add_instance+0xd7/0x2e0 kernel/cpu.c:2458 > > > > cpuhp_state_add_instance include/linux/cpuhotplug.h:386 [inline] > > > > zswap_pool_create+0x2c3/0x5c0 mm/zswap.c:288 > > > > __zswap_pool_create_fallback mm/zswap.c:356 [inline] > > > > zswap_setup+0x3a5/0x820 mm/zswap.c:1781 > > > > zswap_init+0x2d/0x40 mm/zswap.c:1817 > > > > do_one_initcall+0x111/0x6d0 init/main.c:1266 > > > > do_initcall_level init/main.c:1328 [inline] > > > > do_initcalls init/main.c:1344 [inline] > > > > do_basic_setup init/main.c:1363 [inline] > > > > kernel_init_freeable+0x5ae/0x8a0 init/main.c:1577 > > > > kernel_init+0x1e/0x2d0 init/main.c:1466 > > > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > > > > > Freed by task 901: > > > > kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 > > > > kasan_save_track+0x14/0x30 mm/kasan/common.c:68 > > > > kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:582 > > > > poison_slab_object mm/kasan/common.c:247 [inline] > > > > __kasan_slab_free+0x54/0x70 mm/kasan/common.c:264 > > > > kasan_slab_free include/linux/kasan.h:233 [inline] > > > > slab_free_hook mm/slub.c:2338 [inline] > > > > slab_free mm/slub.c:4598 [inline] > > > > kfree+0x14e/0x4d0 mm/slub.c:4746 > > > > zswap_cpu_comp_dead+0xe3/0x1c0 mm/zswap.c:874 > > > > cpuhp_invoke_callback+0x564/0x9d0 kernel/cpu.c:216 > > > > __cpuhp_invoke_callback_range+0x104/0x220 kernel/cpu.c:965 > > > > cpuhp_invoke_callback_range kernel/cpu.c:989 [inline] > > > > cpuhp_down_callbacks kernel/cpu.c:1382 [inline] > > > > _cpu_down+0x41d/0xef0 kernel/cpu.c:1443 > > > > __cpu_down_maps_locked+0x6f/0x90 kernel/cpu.c:1473 > > > > work_for_cpu_fn+0x55/0xa0 kernel/workqueue.c:6719 > > > > process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229 > > > > process_scheduled_works kernel/workqueue.c:3310 [inline] > > > > worker_thread+0x677/0xe90 kernel/workqueue.c:3391 > > > > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > > > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > > > > > The buggy address belongs to the object at ffff8880219f6b00 > > > > which belongs to the cache kmalloc-96 of size 96 > > > > The buggy address is located 68 bytes inside of > > > > freed 96-byte region [ffff8880219f6b00, ffff8880219f6b60) > > > > > > > > The buggy address belongs to the physical page: > > > > page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x219f6 > > > > anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) > > > > page_type: f5(slab) > > > > raw: 00fff00000000000 ffff88801b041280 ffffea0000887d00 dead000000000005 > > > > raw: 0000000000000000 0000000000200020 00000001f5000000 0000000000000000 > > > > page dumped because: kasan: bad access detected > > > > page_owner tracks the page as allocated > > > > page last allocated via order 0, migratetype Unmovable, gfp_mask > > > > 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid > > > > 1 (swapper/0), ts 15792736110, free_ts 14433067061 > > > > set_page_owner include/linux/page_owner.h:32 [inline] > > > > post_alloc_hook+0x2e7/0x350 mm/page_alloc.c:1556 > > > > prep_new_page mm/page_alloc.c:1564 [inline] > > > > get_page_from_freelist+0xe4e/0x2b20 mm/page_alloc.c:3474 > > > > __alloc_pages_noprof+0x219/0x21f0 mm/page_alloc.c:4751 > > > > alloc_pages_mpol_noprof+0x2b6/0x600 mm/mempolicy.c:2265 > > > > alloc_slab_page mm/slub.c:2408 [inline] > > > > allocate_slab mm/slub.c:2574 [inline] > > > > new_slab+0x2d5/0x420 mm/slub.c:2627 > > > > ___slab_alloc+0xbb7/0x1850 mm/slub.c:3815 > > > > __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3905 > > > > __slab_alloc_node mm/slub.c:3980 [inline] > > > > slab_alloc_node mm/slub.c:4141 [inline] > > > > __kmalloc_cache_noprof+0x280/0x410 mm/slub.c:4309 > > > > kmalloc_noprof include/linux/slab.h:901 [inline] > > > > kzalloc_noprof include/linux/slab.h:1037 [inline] > > > > usb_hub_create_port_device+0xbb/0xde0 drivers/usb/core/port.c:743 > > > > hub_configure drivers/usb/core/hub.c:1710 [inline] > > > > hub_probe+0x1ceb/0x2fc0 drivers/usb/core/hub.c:1965 > > > > usb_probe_interface+0x314/0x9f0 drivers/usb/core/driver.c:399 > > > > call_driver_probe drivers/base/dd.c:579 [inline] > > > > really_probe+0x252/0xa90 drivers/base/dd.c:658 > > > > __driver_probe_device+0x1df/0x450 drivers/base/dd.c:800 > > > > driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:830 > > > > __device_attach_driver+0x1db/0x2f0 drivers/base/dd.c:958 > > > > bus_for_each_drv+0x14c/0x1d0 drivers/base/bus.c:459 > > > > page last free pid 25 tgid 25 stack trace: > > > > reset_page_owner include/linux/page_owner.h:25 [inline] > > > > free_pages_prepare mm/page_alloc.c:1127 [inline] > > > > free_unref_page+0x714/0x10c0 mm/page_alloc.c:2657 > > > > vfree+0x17e/0x890 mm/vmalloc.c:3382 > > > > delayed_vfree_work+0x57/0x70 mm/vmalloc.c:3303 > > > > process_one_work+0x9a2/0x1ba0 kernel/workqueue.c:3229 > > > > process_scheduled_works kernel/workqueue.c:3310 [inline] > > > > worker_thread+0x677/0xe90 kernel/workqueue.c:3391 > > > > kthread+0x2ca/0x3b0 kernel/kthread.c:389 > > > > ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 > > > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > > > > > Memory state around the buggy address: > > > > ffff8880219f6a00: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc > > > > ffff8880219f6a80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc > > > > >ffff8880219f6b00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > > > > ^ > > > > ffff8880219f6b80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc > > > > ffff8880219f6c00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > > > > ================================================================== > > > > If you have any questions, please contact us. > > > > > > > > Best Regards, > > > > Yue ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2024-12-19 21:04 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2024-12-17 10:52 [Bug] KASAN: slab-use-after-free Read in zswap_decompress Sam Sun 2024-12-17 16:30 ` Yosry Ahmed 2024-12-17 19:32 ` Yosry Ahmed 2024-12-18 9:17 ` Sam Sun 2024-12-19 21:04 ` Yosry Ahmed
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