syzbot


kernel BUG in f2fs_write_end_io (2)

Status: upstream: reported C repro on 2026/05/14 20:19
Subsystems: f2fs
[Documentation on labels]
Reported-by: syzbot+4af46ee83100e99bce09@syzkaller.appspotmail.com
First crash: 4d23h, last: 4d18h
Cause bisection: failed (error log, bisect log)
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [f2fs?] kernel BUG in f2fs_write_end_io (2) 0 (4) 2026/05/15 01:55
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream kernel BUG in f2fs_write_end_io f2fs -1 C inconclusive 285 10d 408d 29/29 fixed on 2026/05/06 16:40
Last patch testing requests (3)
Created Duration User Patch Repo Result
2026/05/15 01:55 35m kartikey406@gmail.com patch upstream OK log
2026/05/15 01:00 21m kartikey406@gmail.com patch upstream report log
2026/05/14 23:35 24m kartikey406@gmail.com patch upstream report log

Sample crash report:
------------[ cut here ]------------
kernel BUG at fs/f2fs/data.c:388!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 31 Comm: ksoftirqd/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:f2fs_write_end_io+0x16df/0x1740 fs/f2fs/data.c:388
Code: 20 3c 9b 8b e8 12 0a f7 fc 90 0f 0b e8 0a cc 93 fd 48 8b 3c 24 48 c7 c6 20 3c 9b 8b e8 fa 09 f7 fc 90 0f 0b e8 f2 cb 93 fd 90 <0f> 0b e8 ea cb 93 fd 48 8b 3c 24 48 c7 c6 20 3c 9b 8b e8 da 09 f7
RSP: 0018:ffffc90000a5fb18 EFLAGS: 00010246
RAX: ffffffff8430aade RBX: ffffea0000d91c40 RCX: ffff88801d6b0000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000100
RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000100
R10: dffffc0000000000 R11: fffffbfff1f11dff R12: 0000000036471000
R13: ffffea0000d91c80 R14: 000000000000000b R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888126276000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007eff6352cff8 CR3: 000000002caa2000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 blk_update_request+0x57e/0xe60 block/blk-mq.c:1016
 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1178
 blk_complete_reqs block/blk-mq.c:1253 [inline]
 blk_done_softirq+0x10a/0x160 block/blk-mq.c:1258
 handle_softirqs+0x1de/0x6d0 kernel/softirq.c:622
 run_ksoftirqd+0x52/0x180 kernel/softirq.c:1076
 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:f2fs_write_end_io+0x16df/0x1740 fs/f2fs/data.c:388
Code: 20 3c 9b 8b e8 12 0a f7 fc 90 0f 0b e8 0a cc 93 fd 48 8b 3c 24 48 c7 c6 20 3c 9b 8b e8 fa 09 f7 fc 90 0f 0b e8 f2 cb 93 fd 90 <0f> 0b e8 ea cb 93 fd 48 8b 3c 24 48 c7 c6 20 3c 9b 8b e8 da 09 f7
RSP: 0018:ffffc90000a5fb18 EFLAGS: 00010246
RAX: ffffffff8430aade RBX: ffffea0000d91c40 RCX: ffff88801d6b0000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000100
RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000100
R10: dffffc0000000000 R11: fffffbfff1f11dff R12: 0000000036471000
R13: ffffea0000d91c80 R14: 000000000000000b R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888126276000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007eff6352cff8 CR3: 000000002caa2000 CR4: 00000000003526f0

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/11 01:43 upstream aa54b1d27fe0 29233ece .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1 (corrupt fs)] [mounted in repro #2] ci2-upstream-fs kernel BUG in f2fs_write_end_io
2026/05/10 21:32 upstream aa54b1d27fe0 29233ece .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs kernel BUG in f2fs_write_end_io
2026/05/10 20:12 upstream aa54b1d27fe0 29233ece .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in f2fs_write_end_io
* Struck through repros no longer work on HEAD.