* [syzbot] WARNING in __kfence_free @ 2022-04-21 8:58 syzbot 2022-04-21 9:12 ` Marco Elver 2022-04-22 6:06 ` Zhang, Qiang1 0 siblings, 2 replies; 5+ messages in thread From: syzbot @ 2022-04-21 8:58 UTC (permalink / raw) To: akpm, dvyukov, elver, glider, kasan-dev, linux-kernel, linux-mm, syzkaller-bugs Hello, syzbot found the following issue on: HEAD commit: 559089e0a93d vmalloc: replace VM_NO_HUGE_VMAP with VM_ALLO.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=10853220f00000 kernel config: https://syzkaller.appspot.com/x/.config?x=2e1f9b9947966f42 dashboard link: https://syzkaller.appspot.com/bug?extid=ffe71f1ff7f8061bcc98 compiler: aarch64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 userspace arch: arm64 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+ffe71f1ff7f8061bcc98@syzkaller.appspotmail.com ------------[ cut here ]------------ WARNING: CPU: 0 PID: 2216 at mm/kfence/core.c:1022 __kfence_free+0x84/0xc0 mm/kfence/core.c:1022 Modules linked in: CPU: 0 PID: 2216 Comm: syz-executor.0 Not tainted 5.18.0-rc3-syzkaller-00007-g559089e0a93d #0 Hardware name: linux,dummy-virt (DT) pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __kfence_free+0x84/0xc0 mm/kfence/core.c:1022 lr : kfence_free include/linux/kfence.h:186 [inline] lr : __slab_free+0x2e4/0x4d4 mm/slub.c:3315 sp : ffff80000a9fb980 x29: ffff80000a9fb980 x28: ffff80000a280040 x27: f2ff000002c01c00 x26: ffff00007b694040 x25: ffff00007b694000 x24: 0000000000000001 x23: ffff00007b694000 x22: ffff00007b694000 x21: f2ff000002c01c00 x20: ffff80000821accc x19: fffffc0001eda500 x18: 0000000000000002 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 0000000000000001 x13: 000000000005eb7f x12: f7ff000007a08024 x11: f7ff000007a08000 x10: 0000000000000000 x9 : 0000000000000014 x8 : 0000000000000001 x7 : 0000000000094000 x6 : ffff80000a280000 x5 : ffff80000821accc x4 : ffff80000a50e078 x3 : ffff80000a280348 x2 : f0ff00001e325c00 x1 : ffff80000a522b40 x0 : ffff00007b694000 Call trace: __kfence_free+0x84/0xc0 mm/kfence/core.c:1022 kfence_free include/linux/kfence.h:186 [inline] __slab_free+0x2e4/0x4d4 mm/slub.c:3315 do_slab_free mm/slub.c:3498 [inline] slab_free mm/slub.c:3511 [inline] kfree+0x320/0x37c mm/slub.c:4552 kvfree+0x3c/0x50 mm/util.c:615 xt_free_table_info+0x78/0x90 net/netfilter/x_tables.c:1212 __do_replace+0x240/0x330 net/ipv6/netfilter/ip6_tables.c:1104 do_replace net/ipv6/netfilter/ip6_tables.c:1157 [inline] do_ip6t_set_ctl+0x374/0x4e0 net/ipv6/netfilter/ip6_tables.c:1639 nf_setsockopt+0x68/0x94 net/netfilter/nf_sockopt.c:101 ipv6_setsockopt+0xa8/0x220 net/ipv6/ipv6_sockglue.c:1026 tcp_setsockopt+0x38/0xdb4 net/ipv4/tcp.c:3696 sock_common_setsockopt+0x1c/0x30 net/core/sock.c:3505 __sys_setsockopt+0xa0/0x1c0 net/socket.c:2180 __do_sys_setsockopt net/socket.c:2191 [inline] __se_sys_setsockopt net/socket.c:2188 [inline] __arm64_sys_setsockopt+0x2c/0x40 net/socket.c:2188 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x48/0x114 arch/arm64/kernel/syscall.c:52 el0_svc_common.constprop.0+0x44/0xec arch/arm64/kernel/syscall.c:142 do_el0_svc+0x6c/0x84 arch/arm64/kernel/syscall.c:181 el0_svc+0x44/0xb0 arch/arm64/kernel/entry-common.c:616 el0t_64_sync_handler+0x1a4/0x1b0 arch/arm64/kernel/entry-common.c:634 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:581 ---[ end trace 0000000000000000 ]--- --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [syzbot] WARNING in __kfence_free 2022-04-21 8:58 [syzbot] WARNING in __kfence_free syzbot @ 2022-04-21 9:12 ` Marco Elver 2022-04-22 5:09 ` Muchun Song 2022-04-22 6:06 ` Zhang, Qiang1 1 sibling, 1 reply; 5+ messages in thread From: Marco Elver @ 2022-04-21 9:12 UTC (permalink / raw) To: syzbot, Muchun Song Cc: akpm, dvyukov, glider, kasan-dev, linux-kernel, linux-mm, syzkaller-bugs, Roman Gushchin, cgroups On Thu, Apr 21, 2022 at 01:58AM -0700, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 559089e0a93d vmalloc: replace VM_NO_HUGE_VMAP with VM_ALLO.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=10853220f00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=2e1f9b9947966f42 > dashboard link: https://syzkaller.appspot.com/bug?extid=ffe71f1ff7f8061bcc98 > compiler: aarch64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > userspace arch: arm64 > > Unfortunately, I don't have any reproducer for this issue yet. > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+ffe71f1ff7f8061bcc98@syzkaller.appspotmail.com > > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 2216 at mm/kfence/core.c:1022 __kfence_free+0x84/0xc0 mm/kfence/core.c:1022 That's this warning in __kfence_free: #ifdef CONFIG_MEMCG KFENCE_WARN_ON(meta->objcg); #endif introduced in 8f0b36497303 ("mm: kfence: fix objcgs vector allocation"). Muchun, are there any circumstances where the assumption may be broken? Or a new bug elsewhere? > Modules linked in: > CPU: 0 PID: 2216 Comm: syz-executor.0 Not tainted 5.18.0-rc3-syzkaller-00007-g559089e0a93d #0 > Hardware name: linux,dummy-virt (DT) > pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : __kfence_free+0x84/0xc0 mm/kfence/core.c:1022 > lr : kfence_free include/linux/kfence.h:186 [inline] > lr : __slab_free+0x2e4/0x4d4 mm/slub.c:3315 > sp : ffff80000a9fb980 > x29: ffff80000a9fb980 x28: ffff80000a280040 x27: f2ff000002c01c00 > x26: ffff00007b694040 x25: ffff00007b694000 x24: 0000000000000001 > x23: ffff00007b694000 x22: ffff00007b694000 x21: f2ff000002c01c00 > x20: ffff80000821accc x19: fffffc0001eda500 x18: 0000000000000002 > x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 > x14: 0000000000000001 x13: 000000000005eb7f x12: f7ff000007a08024 > x11: f7ff000007a08000 x10: 0000000000000000 x9 : 0000000000000014 > x8 : 0000000000000001 x7 : 0000000000094000 x6 : ffff80000a280000 > x5 : ffff80000821accc x4 : ffff80000a50e078 x3 : ffff80000a280348 > x2 : f0ff00001e325c00 x1 : ffff80000a522b40 x0 : ffff00007b694000 > Call trace: > __kfence_free+0x84/0xc0 mm/kfence/core.c:1022 > kfence_free include/linux/kfence.h:186 [inline] > __slab_free+0x2e4/0x4d4 mm/slub.c:3315 > do_slab_free mm/slub.c:3498 [inline] > slab_free mm/slub.c:3511 [inline] > kfree+0x320/0x37c mm/slub.c:4552 > kvfree+0x3c/0x50 mm/util.c:615 > xt_free_table_info+0x78/0x90 net/netfilter/x_tables.c:1212 > __do_replace+0x240/0x330 net/ipv6/netfilter/ip6_tables.c:1104 > do_replace net/ipv6/netfilter/ip6_tables.c:1157 [inline] > do_ip6t_set_ctl+0x374/0x4e0 net/ipv6/netfilter/ip6_tables.c:1639 > nf_setsockopt+0x68/0x94 net/netfilter/nf_sockopt.c:101 > ipv6_setsockopt+0xa8/0x220 net/ipv6/ipv6_sockglue.c:1026 > tcp_setsockopt+0x38/0xdb4 net/ipv4/tcp.c:3696 > sock_common_setsockopt+0x1c/0x30 net/core/sock.c:3505 > __sys_setsockopt+0xa0/0x1c0 net/socket.c:2180 > __do_sys_setsockopt net/socket.c:2191 [inline] > __se_sys_setsockopt net/socket.c:2188 [inline] > __arm64_sys_setsockopt+0x2c/0x40 net/socket.c:2188 > __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] > invoke_syscall+0x48/0x114 arch/arm64/kernel/syscall.c:52 > el0_svc_common.constprop.0+0x44/0xec arch/arm64/kernel/syscall.c:142 > do_el0_svc+0x6c/0x84 arch/arm64/kernel/syscall.c:181 > el0_svc+0x44/0xb0 arch/arm64/kernel/entry-common.c:616 > el0t_64_sync_handler+0x1a4/0x1b0 arch/arm64/kernel/entry-common.c:634 > el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:581 > ---[ end trace 0000000000000000 ]--- > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [syzbot] WARNING in __kfence_free 2022-04-21 9:12 ` Marco Elver @ 2022-04-22 5:09 ` Muchun Song 2022-04-22 10:37 ` Marco Elver 0 siblings, 1 reply; 5+ messages in thread From: Muchun Song @ 2022-04-22 5:09 UTC (permalink / raw) To: Marco Elver Cc: syzbot, akpm, dvyukov, glider, kasan-dev, linux-kernel, linux-mm, syzkaller-bugs, Roman Gushchin, cgroups On Thu, Apr 21, 2022 at 11:12:17AM +0200, Marco Elver wrote: > On Thu, Apr 21, 2022 at 01:58AM -0700, syzbot wrote: > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: 559089e0a93d vmalloc: replace VM_NO_HUGE_VMAP with VM_ALLO.. > > git tree: upstream > > console output: https://syzkaller.appspot.com/x/log.txt?x=10853220f00000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=2e1f9b9947966f42 > > dashboard link: https://syzkaller.appspot.com/bug?extid=ffe71f1ff7f8061bcc98 > > compiler: aarch64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > > userspace arch: arm64 > > > > Unfortunately, I don't have any reproducer for this issue yet. > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+ffe71f1ff7f8061bcc98@syzkaller.appspotmail.com > > > > ------------[ cut here ]------------ > > WARNING: CPU: 0 PID: 2216 at mm/kfence/core.c:1022 __kfence_free+0x84/0xc0 mm/kfence/core.c:1022 > > That's this warning in __kfence_free: > > #ifdef CONFIG_MEMCG > KFENCE_WARN_ON(meta->objcg); > #endif > > introduced in 8f0b36497303 ("mm: kfence: fix objcgs vector allocation"). > > Muchun, are there any circumstances where the assumption may be broken? > Or a new bug elsewhere? meta->objcg always should be NULL when reaching __kfence_free(). In theory, meta->objcg should be cleared via memcg_slab_free_hook(). I found the following code snippet in do_slab_free(). /* memcg_slab_free_hook() is already called for bulk free. */ if (!tail) memcg_slab_free_hook(s, &head, 1); The only posibility is @tail is not NULL, which is the case of kmem_cache_free_bulk(). However, here the call trace is kfree(), it seems to be impossible that missing call memcg_slab_free_hook(). Thanks. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [syzbot] WARNING in __kfence_free 2022-04-22 5:09 ` Muchun Song @ 2022-04-22 10:37 ` Marco Elver 0 siblings, 0 replies; 5+ messages in thread From: Marco Elver @ 2022-04-22 10:37 UTC (permalink / raw) To: Muchun Song Cc: syzbot, akpm, dvyukov, glider, kasan-dev, linux-kernel, linux-mm, syzkaller-bugs, Roman Gushchin, cgroups, Andrey Konovalov On Fri, 22 Apr 2022 at 07:09, Muchun Song <songmuchun@bytedance.com> wrote: > > On Thu, Apr 21, 2022 at 11:12:17AM +0200, Marco Elver wrote: > > On Thu, Apr 21, 2022 at 01:58AM -0700, syzbot wrote: > > > Hello, > > > > > > syzbot found the following issue on: > > > > > > HEAD commit: 559089e0a93d vmalloc: replace VM_NO_HUGE_VMAP with VM_ALLO.. > > > git tree: upstream > > > console output: https://syzkaller.appspot.com/x/log.txt?x=10853220f00000 > > > kernel config: https://syzkaller.appspot.com/x/.config?x=2e1f9b9947966f42 > > > dashboard link: https://syzkaller.appspot.com/bug?extid=ffe71f1ff7f8061bcc98 > > > compiler: aarch64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > > > userspace arch: arm64 > > > > > > Unfortunately, I don't have any reproducer for this issue yet. > > > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > > Reported-by: syzbot+ffe71f1ff7f8061bcc98@syzkaller.appspotmail.com > > > > > > ------------[ cut here ]------------ > > > WARNING: CPU: 0 PID: 2216 at mm/kfence/core.c:1022 __kfence_free+0x84/0xc0 mm/kfence/core.c:1022 > > > > That's this warning in __kfence_free: > > > > #ifdef CONFIG_MEMCG > > KFENCE_WARN_ON(meta->objcg); > > #endif > > > > introduced in 8f0b36497303 ("mm: kfence: fix objcgs vector allocation"). > > > > Muchun, are there any circumstances where the assumption may be broken? > > Or a new bug elsewhere? > > meta->objcg always should be NULL when reaching __kfence_free(). > In theory, meta->objcg should be cleared via memcg_slab_free_hook(). > > I found the following code snippet in do_slab_free(). > > /* memcg_slab_free_hook() is already called for bulk free. */ > if (!tail) > memcg_slab_free_hook(s, &head, 1); > > The only posibility is @tail is not NULL, which is the case of > kmem_cache_free_bulk(). However, here the call trace is kfree(), > it seems to be impossible that missing call memcg_slab_free_hook(). Fair enough - we can probably wait for the bug to reoccur on another instance, and until then assume something else wrong. What is slightly suspicious is that it only occurred once on a QEMU TCG arm64 MTE instance. Thanks, -- Marco ^ permalink raw reply [flat|nested] 5+ messages in thread
* RE: [syzbot] WARNING in __kfence_free 2022-04-21 8:58 [syzbot] WARNING in __kfence_free syzbot 2022-04-21 9:12 ` Marco Elver @ 2022-04-22 6:06 ` Zhang, Qiang1 1 sibling, 0 replies; 5+ messages in thread From: Zhang, Qiang1 @ 2022-04-22 6:06 UTC (permalink / raw) To: syzbot, akpm, dvyukov, elver, glider, kasan-dev, linux-kernel, linux-mm, syzkaller-bugs, songmuchun Cc: Muchun Hello, syzbot found the following issue on: HEAD commit: 559089e0a93d vmalloc: replace VM_NO_HUGE_VMAP with VM_ALLO.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=10853220f00000 kernel config: https://syzkaller.appspot.com/x/.config?x=2e1f9b9947966f42 dashboard link: https://syzkaller.appspot.com/bug?extid=ffe71f1ff7f8061bcc98 compiler: aarch64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 userspace arch: arm64 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+ffe71f1ff7f8061bcc98@syzkaller.appspotmail.com ------------[ cut here ]------------ WARNING: CPU: 0 PID: 2216 at mm/kfence/core.c:1022 __kfence_free+0x84/0xc0 mm/kfence/core.c:1022 Modules linked in: CPU: 0 PID: 2216 Comm: syz-executor.0 Not tainted 5.18.0-rc3-syzkaller-00007-g559089e0a93d #0 Hardware name: linux,dummy-virt (DT) pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __kfence_free+0x84/0xc0 mm/kfence/core.c:1022 lr : kfence_free include/linux/kfence.h:186 [inline] lr : __slab_free+0x2e4/0x4d4 mm/slub.c:3315 sp : ffff80000a9fb980 x29: ffff80000a9fb980 x28: ffff80000a280040 x27: f2ff000002c01c00 x26: ffff00007b694040 x25: ffff00007b694000 x24: 0000000000000001 x23: ffff00007b694000 x22: ffff00007b694000 x21: f2ff000002c01c00 x20: ffff80000821accc x19: fffffc0001eda500 x18: 0000000000000002 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 0000000000000001 x13: 000000000005eb7f x12: f7ff000007a08024 x11: f7ff000007a08000 x10: 0000000000000000 x9 : 0000000000000014 x8 : 0000000000000001 x7 : 0000000000094000 x6 : ffff80000a280000 x5 : ffff80000821accc x4 : ffff80000a50e078 x3 : ffff80000a280348 x2 : f0ff00001e325c00 x1 : ffff80000a522b40 x0 : ffff00007b694000 Call trace: __kfence_free+0x84/0xc0 mm/kfence/core.c:1022 kfence_free include/linux/kfence.h:186 [inline] __slab_free+0x2e4/0x4d4 mm/slub.c:3315 do_slab_free mm/slub.c:3498 [inline] slab_free mm/slub.c:3511 [inline] kfree+0x320/0x37c mm/slub.c:4552 kvfree+0x3c/0x50 mm/util.c:615 xt_free_table_info+0x78/0x90 net/netfilter/x_tables.c:1212 __do_replace+0x240/0x330 net/ipv6/netfilter/ip6_tables.c:1104 do_replace net/ipv6/netfilter/ip6_tables.c:1157 [inline] do_ip6t_set_ctl+0x374/0x4e0 net/ipv6/netfilter/ip6_tables.c:1639 nf_setsockopt+0x68/0x94 net/netfilter/nf_sockopt.c:101 ipv6_setsockopt+0xa8/0x220 net/ipv6/ipv6_sockglue.c:1026 tcp_setsockopt+0x38/0xdb4 net/ipv4/tcp.c:3696 sock_common_setsockopt+0x1c/0x30 net/core/sock.c:3505 __sys_setsockopt+0xa0/0x1c0 net/socket.c:2180 __do_sys_setsockopt net/socket.c:2191 [inline] __se_sys_setsockopt net/socket.c:2188 [inline] __arm64_sys_setsockopt+0x2c/0x40 net/socket.c:2188 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x48/0x114 arch/arm64/kernel/syscall.c:52 el0_svc_common.constprop.0+0x44/0xec arch/arm64/kernel/syscall.c:142 do_el0_svc+0x6c/0x84 arch/arm64/kernel/syscall.c:181 el0_svc+0x44/0xb0 arch/arm64/kernel/entry-common.c:616 el0t_64_sync_handler+0x1a4/0x1b0 arch/arm64/kernel/entry-common.c:634 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:581 ---[ end trace 0000000000000000 ]--- --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2022-04-22 10:38 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2022-04-21 8:58 [syzbot] WARNING in __kfence_free syzbot 2022-04-21 9:12 ` Marco Elver 2022-04-22 5:09 ` Muchun Song 2022-04-22 10:37 ` Marco Elver 2022-04-22 6:06 ` Zhang, Qiang1
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox