[syzbot] [jfs?] kernel BUG in lbmIOWait

[syzbot <syzbot+2e5cf2352e9f69ebf172@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    8cdeaa50eae8 Linux 7.2-rc2
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=136d3546580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=98da55a882774dfe
dashboard link: https://syzkaller.appspot.com/bug?extid=2e5cf2352e9f69ebf172
compiler:       Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/5305ba8cc7ff/disk-8cdeaa50.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9f2a82556517/vmlinux-8cdeaa50.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c5dc14abbf23/bzImage-8cdeaa50.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2e5cf2352e9f69ebf172@syzkaller.appspotmail.com

BUG at fs/jfs/jfs_logmgr.c:1919 assert(bp->l_wqnext == NULL)
------------[ cut here ]------------
kernel BUG at fs/jfs/jfs_logmgr.c:1919!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 8824 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:lbmfree fs/jfs/jfs_logmgr.c:1919 [inline]
RIP: 0010:lbmIOWait+0x5ab/0x5b0 fs/jfs/jfs_logmgr.c:2154
Code: e9 c7 fc ff ff e8 05 5b 66 fe 48 c7 c7 80 dd ab 8b 48 c7 c6 80 d8 ab 8b ba 7f 07 00 00 48 c7 c1 00 e6 ab 8b e8 b6 87 c8 fd 90 <0f> 0b 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55
RSP: 0018:ffffc9000436f9e0 EFLAGS: 00010246
RAX: 000000000000003c RBX: ffff88803d406008 RCX: bd2a06f3b920b600
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000436faf0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff5200086deed R12: 000000000000002e
R13: ffff88803d406010 R14: dffffc0000000000 R15: 1ffff9200086df44
FS:  000055555ba11500(0000) GS:ffff888125c4c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffa20e9d000 CR3: 000000005dbb2000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 lmLogShutdown+0x1ff/0x850 fs/jfs/jfs_logmgr.c:1657
 lmLogClose+0x28c/0x530 fs/jfs/jfs_logmgr.c:1457
 jfs_umount+0x2da/0x3b0 fs/jfs/jfs_umount.c:124
 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194
 generic_shutdown_super+0x13d/0x2d0 fs/super.c:647
 kill_block_super+0x44/0x90 fs/super.c:1665
 deactivate_locked_super+0xbc/0x130 fs/super.c:477
 cleanup_mnt+0x3d3/0x460 fs/namespace.c:1317
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6087c0f097
Code: a2 c7 05 5c 26 25 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007fffcff22d78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f6087ca32ca RCX: 00007f6087c0f097
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffcff22e30
RBP: 00007fffcff22e30 R08: 00007fffcff23e30 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffcff23ec0
R13: 00007f6087ca32ca R14: 0000000000088c2a R15: 00007fffcff23f00
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:lbmfree fs/jfs/jfs_logmgr.c:1919 [inline]
RIP: 0010:lbmIOWait+0x5ab/0x5b0 fs/jfs/jfs_logmgr.c:2154
Code: e9 c7 fc ff ff e8 05 5b 66 fe 48 c7 c7 80 dd ab 8b 48 c7 c6 80 d8 ab 8b ba 7f 07 00 00 48 c7 c1 00 e6 ab 8b e8 b6 87 c8 fd 90 <0f> 0b 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55
RSP: 0018:ffffc9000436f9e0 EFLAGS: 00010246
RAX: 000000000000003c RBX: ffff88803d406008 RCX: bd2a06f3b920b600
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000436faf0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff5200086deed R12: 000000000000002e
R13: ffff88803d406010 R14: dffffc0000000000 R15: 1ffff9200086df44
FS:  000055555ba11500(0000) GS:ffff888125c4c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffa20e9d000 CR3: 000000005dbb2000 CR4: 00000000003526f0


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