linux-kernel - [syzbot] [bcachefs?] kernel BUG in journal_write

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Message-ID: <68d50038.050a0220.25d7ab.0006.GAE@google.com>
Date: Thu, 25 Sep 2025 01:41:28 -0700
From: syzbot <syzbot+91ae1770e6d3697e4c96@...kaller.appspotmail.com>
To: kent.overstreet@...ux.dev, linux-bcachefs@...r.kernel.org, 
	linux-kernel@...r.kernel.org, syzkaller-bugs@...glegroups.com
Subject: [syzbot] [bcachefs?] kernel BUG in journal_write_submit

Hello,

syzbot found the following issue on:

HEAD commit:    3b08f56fbbb9 Merge tag 'x86-urgent-2025-09-20' of git://gi..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13c350e2580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=bf99f2510ef92ba5
dashboard link: https://syzkaller.appspot.com/bug?extid=91ae1770e6d3697e4c96
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-3b08f56f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/db104187bd74/vmlinux-3b08f56f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/978387063602/bzImage-3b08f56f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+91ae1770e6d3697e4c96@...kaller.appspotmail.com

Bluetooth: hci0: command tx timeout
------------[ cut here ]------------
kernel BUG at fs/bcachefs/journal_io.c:1875!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5335 Comm: kworker/u5:2 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: bcachefs_journal journal_write_preflush
RIP: 0010:journal_write_submit+0x1044/0x1090 fs/bcachefs/journal_io.c:1875
Code: 1a f1 ff ff e8 6d da 72 fd 90 0f 0b e8 65 da 72 fd 90 0f 0b e8 5d da 72 fd 90 0f 0b e8 55 da 72 fd 90 0f 0b e8 4d da 72 fd 90 <0f> 0b e8 45 da 72 fd 90 0f 0b e8 3d da 72 fd 90 0f 0b e8 35 da 72
RSP: 0018:ffffc9000d3ef9a0 EFLAGS: 00010293
RAX: ffffffff844ce2f3 RBX: ffff8880333986a0 RCX: ffff88801ca3c880
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888033398000 R08: 0000000000000000 R09: ffffffff84b30fb0
R10: dffffc0000000000 R11: ffffed100aa78007 R12: 0000000000000000
R13: 1ffff110066730d4 R14: 0000000000000000 R15: ffff8880553c0000
FS:  0000000000000000(0000) GS:ffff88808d007000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c93c01a240 CR3: 0000000043e51000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:journal_write_submit+0x1044/0x1090 fs/bcachefs/journal_io.c:1875
Code: 1a f1 ff ff e8 6d da 72 fd 90 0f 0b e8 65 da 72 fd 90 0f 0b e8 5d da 72 fd 90 0f 0b e8 55 da 72 fd 90 0f 0b e8 4d da 72 fd 90 <0f> 0b e8 45 da 72 fd 90 0f 0b e8 3d da 72 fd 90 0f 0b e8 35 da 72
RSP: 0018:ffffc9000d3ef9a0 EFLAGS: 00010293
RAX: ffffffff844ce2f3 RBX: ffff8880333986a0 RCX: ffff88801ca3c880
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888033398000 R08: 0000000000000000 R09: ffffffff84b30fb0
R10: dffffc0000000000 R11: ffffed100aa78007 R12: 0000000000000000
R13: 1ffff110066730d4 R14: 0000000000000000 R15: ffff8880553c0000
FS:  0000000000000000(0000) GS:ffff88808d007000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c93c01a240 CR3: 00000000119f5000 CR4: 0000000000352ef0


---
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