syzbot
kernel BUG in lbmIOWait
Status:
upstream: reported on 2026/07/10 18:24
Subsystems:
jfs
Labels:
prio:normal
[Documentation on labels]
Reported-by: syzbot+2e5cf2352e9f69ebf172@syzkaller.appspotmail.com
First crash: 28d, last: 4d19h
Sample crash report:
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: 7882 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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 45 11 66 fe 48 c7 c7 00 f2 ab 8b 48 c7 c6 00 ed ab 8b ba 7f 07 00 00 48 c7 c1 80 fa ab 8b e8 56 9c c7 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:ffffc90003d47880 EFLAGS: 00010246
RAX: 000000000000003c RBX: ffff88802ab7b208 RCX: 8f7e89dde9899500
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003d47990 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff520007a8ec1 R12: 000000000000002e
R13: ffff88802ab7b210 R14: dffffc0000000000 R15: 1ffff920007a8f18
FS: 0000000000000000(0000) GS:ffff888125c41000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9928604f10 CR3: 00000000378e6000 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:1671
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
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x73a/0x2360 kernel/exit.c:1009
do_group_exit+0x22d/0x2f0 kernel/exit.c:1152
__do_sys_exit_group kernel/exit.c:1163 [inline]
__se_sys_exit_group kernel/exit.c:1161 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1161
x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5a27d6df99
Code: Unable to access opcode bytes at 0x7f5a27d6df6f.
RSP: 002b:00007ffc17e46548 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f5a27e04339 RCX: 00007f5a27d6df99
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000002 R08: 0000000000000000 R09: 00007f5a27e04314
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc17e47800
R13: 00007f5a27e04314 R14: 000000000007184d R15: 00007ffc17e488d0
</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 45 11 66 fe 48 c7 c7 00 f2 ab 8b 48 c7 c6 00 ed ab 8b ba 7f 07 00 00 48 c7 c1 80 fa ab 8b e8 56 9c c7 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:ffffc90003d47880 EFLAGS: 00010246
RAX: 000000000000003c RBX: ffff88802ab7b208 RCX: 8f7e89dde9899500
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003d47990 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff520007a8ec1 R12: 000000000000002e
R13: ffff88802ab7b210 R14: dffffc0000000000 R15: 1ffff920007a8f18
FS: 0000000000000000(0000) GS:ffff888125c41000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9928604f10 CR3: 00000000378e6000 CR4: 00000000003526f0
* Struck through repros no longer work on HEAD.