syzbot


kernel BUG in blk_mq_end_request

Status: upstream: reported C repro on 2025/05/24 01:52
Subsystems: block bcachefs
[Documentation on labels]
Reported-by: syzbot+a8f903ba15921696861d@syzkaller.appspotmail.com
First crash: 4d13h, last: 3d18h
Cause bisection: introduced by (bisect log) :
commit f5095b9f85a1674a92d00e7ab466499a8ba49ce1
Author: Kent Overstreet <kent.overstreet@linux.dev>
Date: Tue Jan 2 00:42:37 2024 +0000

  bcachefs: dev_usage updated by new accounting

Crash: BUG: workqueue lockup (log)
Repro: C syz .config
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [block?] [bcachefs?] kernel BUG in blk_mq_end_request 0 (1) 2025/05/24 01:52

Sample crash report:
------------[ cut here ]------------
kernel BUG at block/blk-mq.c:1146!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 15 Comm: ksoftirqd/0 Not tainted 6.15.0-rc7-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:blk_mq_end_request+0x6c/0x70 block/blk-mq.c:1146
Code: e8 79 f1 2b fd 48 89 df 89 ee 5b 5d e9 bd f9 ff ff 89 f9 80 e1 07 80 c1 03 38 c1 7c ce e8 ec c5 8b fd eb c7 e8 55 f1 2b fd 90 <0f> 0b 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f
RSP: 0018:ffffc90000147bb8 EFLAGS: 00010246
RAX: ffffffff8493ff8b RBX: ffff888024517500 RCX: ffff88801c6cbc00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff88801c6cbc00 R09: 0000000000000003
R10: 0000000000000009 R11: 0000000000000100 R12: dffffc0000000000
R13: 0000000000000005 R14: ffff888024517500 R15: ffffffff8be81688
FS:  0000000000000000(0000) GS:ffff8881260f6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000075daa000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 blk_complete_reqs block/blk-mq.c:1220 [inline]
 blk_done_softirq+0x10a/0x160 block/blk-mq.c:1225
 handle_softirqs+0x283/0x870 kernel/softirq.c:579
 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:968
 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:164
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:blk_mq_end_request+0x6c/0x70 block/blk-mq.c:1146
Code: e8 79 f1 2b fd 48 89 df 89 ee 5b 5d e9 bd f9 ff ff 89 f9 80 e1 07 80 c1 03 38 c1 7c ce e8 ec c5 8b fd eb c7 e8 55 f1 2b fd 90 <0f> 0b 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f
RSP: 0018:ffffc90000147bb8 EFLAGS: 00010246
RAX: ffffffff8493ff8b RBX: ffff888024517500 RCX: ffff88801c6cbc00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff88801c6cbc00 R09: 0000000000000003
R10: 0000000000000009 R11: 0000000000000100 R12: dffffc0000000000
R13: 0000000000000005 R14: ffff888024517500 R15: ffffffff8be81688
FS:  0000000000000000(0000) GS:ffff8881260f6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000075daa000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/05/20 20:41 upstream a5806cd506af b47f9e02 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2 (corrupt fs)] ci2-upstream-fs kernel BUG in blk_mq_end_request
2025/05/20 17:41 upstream a5806cd506af b47f9e02 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs kernel BUG in blk_mq_end_request
2025/05/20 01:42 upstream a5806cd506af b84f0537 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs kernel BUG in blk_mq_end_request
* Struck through repros no longer work on HEAD.