In the Linux kernel, the following vulnerability has been resolved:

f2fs: fix to avoid potential deadlock

As Jiaming Zhang and syzbot reported, there is potential deadlock in
f2fs as below:

Chain exists of:
&sbi->cp_rwsem --> fs_reclaim --> sb_internal#2

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
rlock(sb_internal#2);
lock(fs_reclaim);
lock(sb_internal#2);
rlock(&sbi->cp_rwsem);

*** DEADLOCK ***

3 locks held by kswapd0/73:
#0: ffffffff8e247a40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:7015 [inline]
#0: ffffffff8e247a40 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0x951/0x2800 mm/vmscan.c:7389
#1: ffff8880118400e0 (&type->s_umount_key#50){.+.+}-{4:4}, at: super_trylock_shared fs/super.c:562 [inline]
#1: ffff8880118400e0 (&type->s_umount_key#50){.+.+}-{4:4}, at: super_cache_scan+0x91/0x4b0 fs/super.c:197
#2: ffff888011840610 (sb_internal#2){.+.+}-{0:0}, at: f2fs_evict_inode+0x8d9/0x1b60 fs/f2fs/inode.c:890

stack backtrace:
CPU: 0 UID: 0 PID: 73 Comm: kswapd0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043
check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
__lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
down_read+0x46/0x2e0 kernel/locking/rwsem.c:1537
f2fs_down_read fs/f2fs/f2fs.h:2278 [inline]
f2fs_lock_op fs/f2fs/f2fs.h:2357 [inline]
f2fs_do_truncate_blocks+0x21c/0x10c0 fs/f2fs/file.c:791
f2fs_truncate_blocks+0x10a/0x300 fs/f2fs/file.c:867
f2fs_truncate+0x489/0x7c0 fs/f2fs/file.c:925
f2fs_evict_inode+0x9f2/0x1b60 fs/f2fs/inode.c:897
evict+0x504/0x9c0 fs/inode.c:810
f2fs_evict_inode+0x1dc/0x1b60 fs/f2fs/inode.c:853
evict+0x504/0x9c0 fs/inode.c:810
dispose_list fs/inode.c:852 [inline]
prune_icache_sb+0x21b/0x2c0 fs/inode.c:1000
super_cache_scan+0x39b/0x4b0 fs/super.c:224
do_shrink_slab+0x6ef/0x1110 mm/shrinker.c:437
shrink_slab_memcg mm/shrinker.c:550 [inline]
shrink_slab+0x7ef/0x10d0 mm/shrinker.c:628
shrink_one+0x28a/0x7c0 mm/vmscan.c:4955
shrink_many mm/vmscan.c:5016 [inline]
lru_gen_shrink_node mm/vmscan.c:5094 [inline]
shrink_node+0x315d/0x3780 mm/vmscan.c:6081
kswapd_shrink_node mm/vmscan.c:6941 [inline]
balance_pgdat mm/vmscan.c:7124 [inline]
kswapd+0x147c/0x2800 mm/vmscan.c:7389
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>

The root cause is deadlock among four locks as below:

kswapd
- fs_reclaim --- Lock A
- shrink_one
- evict
- f2fs_evict_inode
- sb_start_intwrite --- Lock B

- iput
- evict
- f2fs_evict_inode
- sb_start_intwrite --- Lock B
- f2fs_truncate
- f2fs_truncate_blocks
- f2fs_do_truncate_blocks
- f2fs_lock_op --- Lock C

ioctl
- f2fs_ioc_commit_atomic_write
- f2fs_lock_op --- Lock C
- __f2fs_commit_atomic_write
- __replace_atomic_write_block
- f2fs_get_dnode_of_data
- __get_node_folio
- f2fs_check_nid_range
- f2fs_handle_error
- f2fs_record_errors
- f2fs_down_write --- Lock D

open
- do_open
- do_truncate
- security_inode_need_killpriv
- f2fs_getxattr
- lookup_all_xattrs
- f2fs_handle_error
- f2fs_record_errors
- f2fs_down_write --- Lock D
- f2fs_commit_super
- read_mapping_folio
- filemap_alloc_folio_noprof
- prepare_alloc_pages
- fs_reclaim_acquire --- Lock A

In order to a
---truncated---

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History

Thu, 15 Jan 2026 00:15:00 +0000


Tue, 13 Jan 2026 15:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid potential deadlock As Jiaming Zhang and syzbot reported, there is potential deadlock in f2fs as below: Chain exists of: &sbi->cp_rwsem --> fs_reclaim --> sb_internal#2 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(sb_internal#2); lock(fs_reclaim); lock(sb_internal#2); rlock(&sbi->cp_rwsem); *** DEADLOCK *** 3 locks held by kswapd0/73: #0: ffffffff8e247a40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:7015 [inline] #0: ffffffff8e247a40 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0x951/0x2800 mm/vmscan.c:7389 #1: ffff8880118400e0 (&type->s_umount_key#50){.+.+}-{4:4}, at: super_trylock_shared fs/super.c:562 [inline] #1: ffff8880118400e0 (&type->s_umount_key#50){.+.+}-{4:4}, at: super_cache_scan+0x91/0x4b0 fs/super.c:197 #2: ffff888011840610 (sb_internal#2){.+.+}-{0:0}, at: f2fs_evict_inode+0x8d9/0x1b60 fs/f2fs/inode.c:890 stack backtrace: CPU: 0 UID: 0 PID: 73 Comm: kswapd0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1537 f2fs_down_read fs/f2fs/f2fs.h:2278 [inline] f2fs_lock_op fs/f2fs/f2fs.h:2357 [inline] f2fs_do_truncate_blocks+0x21c/0x10c0 fs/f2fs/file.c:791 f2fs_truncate_blocks+0x10a/0x300 fs/f2fs/file.c:867 f2fs_truncate+0x489/0x7c0 fs/f2fs/file.c:925 f2fs_evict_inode+0x9f2/0x1b60 fs/f2fs/inode.c:897 evict+0x504/0x9c0 fs/inode.c:810 f2fs_evict_inode+0x1dc/0x1b60 fs/f2fs/inode.c:853 evict+0x504/0x9c0 fs/inode.c:810 dispose_list fs/inode.c:852 [inline] prune_icache_sb+0x21b/0x2c0 fs/inode.c:1000 super_cache_scan+0x39b/0x4b0 fs/super.c:224 do_shrink_slab+0x6ef/0x1110 mm/shrinker.c:437 shrink_slab_memcg mm/shrinker.c:550 [inline] shrink_slab+0x7ef/0x10d0 mm/shrinker.c:628 shrink_one+0x28a/0x7c0 mm/vmscan.c:4955 shrink_many mm/vmscan.c:5016 [inline] lru_gen_shrink_node mm/vmscan.c:5094 [inline] shrink_node+0x315d/0x3780 mm/vmscan.c:6081 kswapd_shrink_node mm/vmscan.c:6941 [inline] balance_pgdat mm/vmscan.c:7124 [inline] kswapd+0x147c/0x2800 mm/vmscan.c:7389 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK> The root cause is deadlock among four locks as below: kswapd - fs_reclaim --- Lock A - shrink_one - evict - f2fs_evict_inode - sb_start_intwrite --- Lock B - iput - evict - f2fs_evict_inode - sb_start_intwrite --- Lock B - f2fs_truncate - f2fs_truncate_blocks - f2fs_do_truncate_blocks - f2fs_lock_op --- Lock C ioctl - f2fs_ioc_commit_atomic_write - f2fs_lock_op --- Lock C - __f2fs_commit_atomic_write - __replace_atomic_write_block - f2fs_get_dnode_of_data - __get_node_folio - f2fs_check_nid_range - f2fs_handle_error - f2fs_record_errors - f2fs_down_write --- Lock D open - do_open - do_truncate - security_inode_need_killpriv - f2fs_getxattr - lookup_all_xattrs - f2fs_handle_error - f2fs_record_errors - f2fs_down_write --- Lock D - f2fs_commit_super - read_mapping_folio - filemap_alloc_folio_noprof - prepare_alloc_pages - fs_reclaim_acquire --- Lock A In order to a ---truncated---
Title f2fs: fix to avoid potential deadlock
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-02-09T08:34:15.556Z

Reserved: 2026-01-13T15:30:19.646Z

Link: CVE-2025-71065

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-01-13T16:16:05.853

Modified: 2026-01-14T16:26:00.933

Link: CVE-2025-71065

cve-icon Redhat

Severity :

Publid Date: 2026-01-13T00:00:00Z

Links: CVE-2025-71065 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses

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