CVE: CVE-2023-53829
Published: 2025-12-09
Description: In the Linux kernel, the following vulnerability has been resolved:

f2fs: flush inode if atomic file is aborted

Let's flush the inode being aborted atomic operation to avoid stale dirty
inode during eviction in this call stack:

  f2fs_mark_inode_dirty_sync+0x22/0x40 [f2fs]
  f2fs_abort_atomic_write+0xc4/0xf0 [f2fs]
  f2fs_evict_inode+0x3f/0x690 [f2fs]
  ? sugov_start+0x140/0x140
  evict+0xc3/0x1c0
  evict_inodes+0x17b/0x210
  generic_shutdown_super+0x32/0x120
  kill_block_super+0x21/0x50
  deactivate_locked_super+0x31/0x90
  cleanup_mnt+0x100/0x160
  task_work_run+0x59/0x90
  do_exit+0x33b/0xa50
  do_group_exit+0x2d/0x80
  __x64_sys_exit_group+0x14/0x20
  do_syscall_64+0x3b/0x90
  entry_SYSCALL_64_after_hwframe+0x63/0xcd

This triggers f2fs_bug_on() in f2fs_evict_inode:
 f2fs_bug_on(sbi, is_inode_flag_set(inode, FI_DIRTY_INODE));

This fixes the syzbot report:

loop0: detected capacity change from 0 to 131072
F2FS-fs (loop0): invalid crc value
F2FS-fs (loop0): Found nat_bits in checkpoint
F2FS-fs (loop0): Mounted with checkpoint version = 48b305e4
------------[ cut here ]------------
kernel BUG at fs/f2fs/inode.c:869!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 5014 Comm: syz-executor220 Not tainted 6.4.0-syzkaller-11479-g6cd06ab12d1a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
RIP: 0010:f2fs_evict_inode+0x172d/0x1e00 fs/f2fs/inode.c:869
Code: ff df 48 c1 ea 03 80 3c 02 00 0f 85 6a 06 00 00 8b 75 40 ba 01 00 00 00 4c 89 e7 e8 6d ce 06 00 e9 aa fc ff ff e8 63 22 e2 fd <0f> 0b e8 5c 22 e2 fd 48 c7 c0 a8 3a 18 8d 48 ba 00 00 00 00 00 fc
RSP: 0018:ffffc90003a6fa00 EFLAGS: 00010293
RAX: [PII_REDACTED] RBX: [PII_REDACTED] RCX: [PII_REDACTED]
RDX: ffff8880273b8000 RSI: ffffffff83a2bd0d RDI: [PII_REDACTED]
RBP: ffff888077db91b0 R08: [PII_REDACTED] R09: [PII_REDACTED]
R10: [PII_REDACTED] R11: [PII_REDACTED] R12: ffff888029a3c000
R13: ffff888077db9660 R14: ffff888029a3c0b8 R15: ffff888077db9c50
FS:  [PII_REDACTED](0000) GS:ffff8880b9800000(0000) knlGS:[PII_REDACTED]
CS:  0010 DS: 0000 ES: 0000 CR0: [PII_REDACTED]
CR2: 00007f1909bb9000 CR3:[PII_REDACTED]6a9000 CR4:[PII_REDACTED]350ef0
Call Trace:
 <TASK>
 evict+0x2ed/0x6b0 fs/inode.c:665
 dispose_list+0x117/0x1e0 fs/inode.c:698
 evict_inodes+0x345/0x440 fs/inode.c:748
 generic_shutdown_super+0xaf/0x480 fs/super.c:478
 kill_block_super+0x64/0xb0 fs/super.c:1417
 kill_f2fs_super+0x2af/0x3c0 fs/f2fs/super.c:4704
 deactivate_locked_super+0x98/0x160 fs/super.c:330
 deactivate_super+0xb1/0xd0 fs/super.c:361
 cleanup_mnt+0x2ae/0x3d0 fs/namespace.c:1254
 task_work_run+0x16f/0x270 kernel/task_work.c:179
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xa9a/0x29a0 kernel/exit.c:874
 do_group_exit+0xd4/0x2a0 kernel/exit.c:1024
 __do_sys_exit_group kernel/exit.c:1035 [inline]
 __se_sys_exit_group kernel/exit.c:1033 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1033
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f309be71a09
Code: Unable to access opcode bytes at 0x7f309be719df.
RSP: 002b:00007fff171df518 EFLAGS: 00000246 ORIG_RAX:[PII_REDACTED]0000e7
RAX: ffffffffffffffda RBX: 00007f309bef7330 RCX: 00007f309be71a09
RDX:[PII_REDACTED]00003c RSI:[PII_REDACTED]0000e7 RDI: [PII_REDACTED]
RBP: [PII_REDACTED] R08: ffffffffffffffc0 R09: 00007f309bef1e40
R10: [PII_REDACTED] R11: [PII_REDACTED] R12: 00007f309bef7330
R13: [PII_REDACTED] R14: [PII_REDACTED] R15: [PII_REDACTED]
 </TASK>
Modules linked in:
---[ end trace [PII_REDACTED] ]---
RIP: 0010:f2fs_evict_inode+0x172d/0x1e00 fs/f2fs/inode.c:869
Code: ff df 48 c1 ea 03 80 3c 02 00 0f 85 6a 06 00 00 8b 75 40 ba 01 00 00 00 4c 89 e7 e8 6d ce 06 00 e9 aa fc ff ff e8 63 22 e2 fd <0f> 0b e8 5c 22 e2 fd 48 c7 c0 a8 3a 18 8d 48 ba 00 00 00 00 00 fc
RSP: 0018:ffffc90003a6fa00 EFLAGS: 00010293
RAX: [PII_REDACTED] RBX:[PII_REDACTED]
---truncated---
References: https://git.kernel.org/stable/c/1c64dbe8fa3552a340bca6d7fa09468c16ed2a85; https://git.kernel.org/stable/c/a3ab[PII_REDACTED]7ce3dcaac6de66f5ffc055b9df; https://git.kernel.org/stable/c/bfa7853bb47fee0c17030b377c98cf4ede47ba33