Message-ID: <6831265e.a70a0220.29d4a0.07f0.GAE@google.com>
Date: Fri, 23 May 2025 18:52:30 -0700
From: syzbot <syzbot+a8f903ba15921696861d@...kaller.appspotmail.com>
To: axboe@...nel.dk, kent.overstreet@...ux.dev, linux-bcachefs@...r.kernel.org, 
	linux-block@...r.kernel.org, linux-kernel@...r.kernel.org, 
	syzkaller-bugs@...glegroups.com
Subject: [syzbot] [block?] [bcachefs?] kernel BUG in blk_mq_end_request

Hello,

syzbot found the following issue on:

HEAD commit:    a5806cd506af Linux 6.15-rc7
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=131bde70580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a1de0d8596cea805
dashboard link: https://syzkaller.appspot.com/bug?extid=a8f903ba15921696861d
compiler:       Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16bb32d4580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=142351f4580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d72f8f4a220d/disk-a5806cd5.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6567d0e5a4d8/vmlinux-a5806cd5.xz
kernel image: https://storage.googleapis.com/syzbot-assets/66e79750c483/bzImage-a5806cd5.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/7fdb68bab5ea/mount_0.gz

The issue was bisected to:

commit f5095b9f85a1674a92d00e7ab466499a8ba49ce1
Author: Kent Overstreet <kent.overstreet@...ux.dev>
Date:   Tue Jan 2 00:42:37 2024 +0000

    bcachefs: dev_usage updated by new accounting

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=14897e70580000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=16897e70580000
console output: https://syzkaller.appspot.com/x/log.txt?x=12897e70580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a8f903ba15921696861d@...kaller.appspotmail.com
Fixes: f5095b9f85a1 ("bcachefs: dev_usage updated by new accounting")

------------[ 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: ffff8880242d1200 RCX: ffff88801c6d3c00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff88801c6d3c00 R09: 0000000000000003
R10: 0000000000000009 R11: 0000000000000100 R12: dffffc0000000000
R13: 0000000000000005 R14: ffff8880242d1200 R15: ffffffff8be81688
FS:  0000000000000000(0000) GS:ffff8881260f6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000007cdd8000 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: ffff8880242d1200 RCX: ffff88801c6d3c00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff88801c6d3c00 R09: 0000000000000003
R10: 0000000000000009 R11: 0000000000000100 R12: dffffc0000000000
R13: 0000000000000005 R14: ffff8880242d1200 R15: ffffffff8be81688
FS:  0000000000000000(0000) GS:ffff8881260f6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000007cdd8000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@...glegroups.com.

syzbot will keep track of this issue. See:
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For information about bisection process see: https://goo.gl/tpsmEJ#bisection

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
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If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

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