CVE-2023-53829
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: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000 RDX: ffff8880273b8000 RSI: ffffffff83a2bd0d RDI: 0000000000000007 RBP: ffff888077db91b0 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffff888029a3c000 R13: ffff888077db9660 R14: ffff888029a3c0b8 R15: ffff888077db9c50 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1909bb9000 CR3: 00000000276a9000 CR4: 0000000000350ef0 Call Trace:
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: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f309bef7330 RCX: 00007f309be71a09 RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000001 RBP: 0000000000000001 R08: ffffffffffffffc0 R09: 00007f309bef1e40 R10: 0000000000010600 R11: 0000000000000246 R12: 00007f309bef7330 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001
Modules linked in: ---[ end trace 0000000000000000 ]--- 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: 0000000000000000 RBX: 0000000000 ---truncated---
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
A bug in the Linux kernel's f2fs filesystem can cause a kernel BUG_ON crash when an aborted atomic write inode is evicted.
Vulnerability
In the Linux kernel's f2fs filesystem, when an atomic write operation is aborted, the inode's dirty state is not properly flushed before eviction. This leads to a kernel BUG_ON crash in f2fs_evict_inode() because the inode still has the FI_DIRTY_INODE flag set, triggering the assertion f2fs_bug_on(sbi, is_inode_flag_set(inode, FI_DIRTY_INODE)) [1].
Exploitation
The vulnerability is triggered through a specific call stack: f2fs_abort_atomic_write marks the inode dirty via f2fs_mark_inode_dirty_sync, but the inode is not flushed before f2fs_evict_inode runs during unmount or filesystem shutdown. An attacker with local access and the ability to mount a crafted f2fs2fs filesystem and perform atomic write operations can cause a denial of service by triggering this crash [1].
Impact
Successful exploitation results in a kernel panic (BUG_ON), leading to a denial of service. The crash occurs during filesystem eviction, which can happen on unmount or when the filesystem is shut down. The bug was discovered via syzkaller fuzzing, indicating it can be reliably triggered [1].
Mitigation
The fix is included in Linux kernel stable updates. The commit a3ab55746612 (and backport bfa7853bb47f) ensures that the inode is flushed after aborting an atomic write, preventing the stale dirty flag from causing the BUG_ON. Users should update their kernel to a version containing this fix [1][2].
AI Insight generated on May 19, 2026. Synthesized from this CVE's description and the cited reference URLs; citations are validated against the source bundle.
Affected products
2Patches
31c64dbe8fa35bfa7853bb47fa3ab55746612Vulnerability mechanics
Generated on May 9, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.
References
3News mentions
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