Re: [syzbot] [mm?] [f2fs?] [exfat?] memory leak in __kfree_rcu_sheaf

syzbot
2026-03-20T10:34:08Z

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
memory leak in __pcs_replace_empty_main

BUG: memory leak
unreferenced object 0xffff88810005f800 (size 512):
comm "swapper/0", pid 0, jiffies 4294937296
hex dump (first 32 bytes):
60 bd 2a 2f 81 88 ff ff 30 ba ad 81 ff ff ff ff `.*/....0.......
00 12 04 00 81 88 ff ff 3c 00 00 00 00 00 00 00 ........<.......
backtrace (crc 81834c79):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4543 [inline]
slab_alloc_node mm/slub.c:4866 [inline]
__do_kmalloc_node mm/slub.c:5259 [inline]
__kmalloc_noprof+0x3bd/0x560 mm/slub.c:5272
kmalloc_noprof include/linux/slab.h:954 [inline]
kzalloc_noprof include/linux/slab.h:1188 [inline]
__alloc_empty_sheaf+0x35/0x50 mm/slub.c:2764
alloc_empty_sheaf mm/slub.c:2779 [inline]
alloc_full_sheaf mm/slub.c:2829 [inline]
__pcs_replace_empty_main+0x1e0/0x2f0 mm/slub.c:4626
alloc_from_pcs mm/slub.c:4717 [inline]
slab_alloc_node mm/slub.c:4851 [inline]
__kmalloc_cache_noprof+0x3ac/0x480 mm/slub.c:5375
kmalloc_noprof include/linux/slab.h:950 [inline]
kzalloc_noprof include/linux/slab.h:1188 [inline]
__irq_domain_alloc_fwnode+0x37/0x140 kernel/irq/irqdomain.c:95
irq_domain_alloc_named_fwnode include/linux/irqdomain.h:271 [inline]
arch_early_irq_init+0x1c/0x70 arch/x86/kernel/apic/vector.c:803
start_kernel+0x931/0xb80 init/main.c:1114
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0xce/0xd0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148

BUG: memory leak
unreferenced object 0xffff8881008f6c00 (size 512):
comm "kthreadd", pid 2, jiffies 4294937342
hex dump (first 32 bytes):
d0 16 c9 29 81 88 ff ff 30 ba ad 81 ff ff ff ff ...)....0.......
00 12 04 00 81 88 ff ff 3c 00 00 00 00 00 00 00 ........<.......
backtrace (crc 38b48d73):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4543 [inline]
slab_alloc_node mm/slub.c:4866 [inline]
__do_kmalloc_node mm/slub.c:5259 [inline]
__kmalloc_noprof+0x3bd/0x560 mm/slub.c:5272
kmalloc_noprof include/linux/slab.h:954 [inline]
kzalloc_noprof include/linux/slab.h:1188 [inline]
__alloc_empty_sheaf+0x35/0x50 mm/slub.c:2764
alloc_empty_sheaf mm/slub.c:2779 [inline]
alloc_full_sheaf mm/slub.c:2829 [inline]
__pcs_replace_empty_main+0x1e0/0x2f0 mm/slub.c:4626
alloc_from_pcs mm/slub.c:4717 [inline]
slab_alloc_node mm/slub.c:4851 [inline]
__kmalloc_cache_node_noprof+0x3ef/0x4e0 mm/slub.c:5388
kmalloc_node_noprof include/linux/slab.h:1077 [inline]
__get_vm_area_node+0xc6/0x1d0 mm/vmalloc.c:3221
__vmalloc_node_range_noprof+0x1d3/0xe50 mm/vmalloc.c:4024
__vmalloc_node_noprof+0x71/0x90 mm/vmalloc.c:4124
alloc_thread_stack_node kernel/fork.c:355 [inline]
dup_task_struct kernel/fork.c:924 [inline]
copy_process+0x3e5/0x28c0 kernel/fork.c:2050
kernel_clone+0xac/0x6e0 kernel/fork.c:2653
kernel_thread+0x80/0xb0 kernel/fork.c:2714
create_kthread kernel/kthread.c:459 [inline]
kthreadd+0x186/0x250 kernel/kthread.c:817
ret_from_fork+0x23c/0x4b0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

BUG: memory leak
unreferenced object 0xffff888102011400 (size 512):
comm "kworker/u8:1", pid 274, jiffies 4294937433
hex dump (first 32 bytes):
28 f6 7b 31 81 88 ff ff 30 ba ad 81 ff ff ff ff (.{1....0.......
00 12 04 00 81 88 ff ff 3c 00 00 00 00 00 00 00 ........<.......
backtrace (crc c5ce2dfb):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4543 [inline]
slab_alloc_node mm/slub.c:4866 [inline]
__do_kmalloc_node mm/slub.c:5259 [inline]
__kmalloc_noprof+0x3bd/0x560 mm/slub.c:5272
kmalloc_noprof include/linux/slab.h:954 [inline]
kzalloc_noprof include/linux/slab.h:1188 [inline]
__alloc_empty_sheaf+0x35/0x50 mm/slub.c:2764
alloc_empty_sheaf mm/slub.c:2779 [inline]
__pcs_replace_full_main+0xe8/0x300 mm/slub.c:5722
free_to_pcs mm/slub.c:5775 [inline]
slab_free mm/slub.c:6170 [inline]
kfree+0x352/0x390 mm/slub.c:6483
call_usermodehelper_freeinfo kernel/umh.c:43 [inline]
umh_complete kernel/umh.c:57 [inline]
call_usermodehelper_exec_async+0x1c7/0x1f0 kernel/umh.c:119
ret_from_fork+0x23c/0x4b0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

BUG: memory leak
unreferenced object 0xffff888102010600 (size 512):
comm "kworker/1:1", pid 41, jiffies 4294937437
hex dump (first 32 bytes):
88 c3 c4 29 81 88 ff ff 30 ba ad 81 ff ff ff ff ...)....0.......
00 12 04 00 81 88 ff ff 3c 00 00 00 00 00 00 00 ........<.......
backtrace (crc 5d48f1c0):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4543 [inline]
slab_alloc_node mm/slub.c:4866 [inline]
__do_kmalloc_node mm/slub.c:5259 [inline]
__kmalloc_noprof+0x3bd/0x560 mm/slub.c:5272
kmalloc_noprof include/linux/slab.h:954 [inline]
kzalloc_noprof include/linux/slab.h:1188 [inline]
__alloc_empty_sheaf+0x35/0x50 mm/slub.c:2764
alloc_empty_sheaf mm/slub.c:2779 [inline]
__pcs_replace_full_main+0xe8/0x300 mm/slub.c:5722
free_to_pcs mm/slub.c:5775 [inline]
slab_free mm/slub.c:6170 [inline]
kfree+0x352/0x390 mm/slub.c:6483
vfree.part.0+0x1d5/0x4d0 mm/vmalloc.c:3485
vfree mm/vmalloc.c:3456 [inline]
delayed_vfree_work+0x5b/0x90 mm/vmalloc.c:3398
process_one_work+0x277/0x5f0 kernel/workqueue.c:3276
process_scheduled_works kernel/workqueue.c:3359 [inline]
worker_thread+0x255/0x4a0 kernel/workqueue.c:3440
kthread+0x14e/0x1a0 kernel/kthread.c:436
ret_from_fork+0x23c/0x4b0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

BUG: memory leak
unreferenced object 0xffff888102010400 (size 512):
comm "kworker/u8:1", pid 443, jiffies 4294937439
hex dump (first 32 bytes):
e8 50 dd 31 81 88 ff ff 30 ba ad 81 ff ff ff ff .P.1....0.......
00 12 04 00 81 88 ff ff 3c 00 00 00 00 00 00 00 ........<.......
backtrace (crc 11032afc):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4543 [inline]
slab_alloc_node mm/slub.c:4866 [inline]
__do_kmalloc_node mm/slub.c:5259 [inline]
__kmalloc_noprof+0x3bd/0x560 mm/slub.c:5272
kmalloc_noprof include/linux/slab.h:954 [inline]
kzalloc_noprof include/linux/slab.h:1188 [inline]
__alloc_empty_sheaf+0x35/0x50 mm/slub.c:2764
alloc_empty_sheaf mm/slub.c:2779 [inline]
__pcs_replace_full_main+0xe8/0x300 mm/slub.c:5722
free_to_pcs mm/slub.c:5775 [inline]
slab_free mm/slub.c:6170 [inline]
kfree+0x352/0x390 mm/slub.c:6483
call_usermodehelper_freeinfo kernel/umh.c:43 [inline]
umh_complete kernel/umh.c:57 [inline]
call_usermodehelper_exec_async+0x1c7/0x1f0 kernel/umh.c:119
ret_from_fork+0x23c/0x4b0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

BUG: memory leak
unreferenced object 0xffff8881095d5a00 (size 256):
comm "swapper/0", pid 1, jiffies 4294937857
hex dump (first 32 bytes):
00 d4 9c 1d 81 88 ff ff 88 fc 04 00 81 88 ff ff ................
00 1a 04 00 81 88 ff ff 1c 00 00 00 00 00 00 00 ................
backtrace (crc deebd371):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4543 [inline]
slab_alloc_node mm/slub.c:4866 [inline]
__do_kmalloc_node mm/slub.c:5259 [inline]
__kmalloc_noprof+0x3bd/0x560 mm/slub.c:5272
kmalloc_noprof include/linux/slab.h:954 [inline]
kzalloc_noprof include/linux/slab.h:1188 [inline]
__alloc_empty_sheaf+0x35/0x50 mm/slub.c:2764
alloc_empty_sheaf mm/slub.c:2779 [inline]
alloc_full_sheaf mm/slub.c:2829 [inline]
__pcs_replace_empty_main+0x1e0/0x2f0 mm/slub.c:4626
alloc_from_pcs mm/slub.c:4717 [inline]
slab_alloc_node mm/slub.c:4851 [inline]
__kmalloc_cache_noprof+0x3ac/0x480 mm/slub.c:5375
kmalloc_noprof include/linux/slab.h:950 [inline]
kzalloc_noprof include/linux/slab.h:1188 [inline]
init_srcu_struct_fields+0x29d/0x320 kernel/rcu/srcutree.c:241
rtnl_link_register+0x81/0x1c0 net/core/rtnetlink.c:615
ipgre_init+0x10d/0x1a0 net/ipv4/ip_gre.c:1828
do_one_initcall+0x79/0x4c0 init/main.c:1382
do_initcall_level init/main.c:1444 [inline]
do_initcalls init/main.c:1460 [inline]
do_basic_setup init/main.c:1479 [inline]
kernel_init_freeable+0x2a4/0x340 init/main.c:1692
kernel_init+0x1b/0x1d0 init/main.c:1582
ret_from_fork+0x23c/0x4b0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

connection error: failed to recv *flatrpc.ExecutorMessageRawT: EOF

Tested on:

commit: 0e4f8f1a Merge tag 'parisc-for-7.0-rc5' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13b18cba580000
kernel config: https://syzkaller.appspot.com/x/.config?x=e2bba615ee79faa5
dashboard link: https://syzkaller.appspot.com/bug?extid=cae7809e9dc1459e4e63
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
patch: https://syzkaller.appspot.com/x/patch.diff?x=12608cba580000