syzbot
kernel BUG in jfs_flush_journal (3)
Status:
upstream: reported on 2026/03/01 21:09
Subsystems:
jfs
Labels:
prio:high
[Documentation on labels]
Reported-by: syzbot+4c8d1f29732a21567e4e@syzkaller.appspotmail.com
First crash: 246d, last: 2d02h
Sample crash report:
BUG at fs/jfs/jfs_logmgr.c:1585 assert(list_empty(&log->cqueue))
------------[ cut here ]------------
kernel BUG at fs/jfs/jfs_logmgr.c:1585!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 9712 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:jfs_flush_journal+0xf2b/0xf50 fs/jfs/jfs_logmgr.c:1585
Code: e9 9e f5 ff ff e8 75 09 54 fe 48 c7 c7 00 f2 cd 8b 48 c7 c6 00 ed cd 8b ba 31 06 00 00 48 c7 c1 40 f2 cd 8b e8 b6 9d b3 fd 90 <0f> 0b e8 4e 09 54 fe bf 02 00 00 00 e8 64 ab 21 fe e9 a9 f7 ff ff
RSP: 0018:ffffc900044979c0 EFLAGS: 00010246
RAX: 0000000000000040 RBX: dffffc0000000000 RCX: d7996471a1db3100
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90004497b00 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff52000892ee9 R12: 00000000000000c7
R13: ffff88803f245a18 R14: ffff88803f245800 R15: ffff88803f245ad8
FS: 0000000000000000(0000) GS:ffff88812482f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb5d95e1e9c CR3: 000000000f1b0000 CR4: 00000000003526f0
Call Trace:
<TASK>
jfs_umount+0x150/0x3b0 fs/jfs/jfs_umount.c:59
jfs_put_super+0x8c/0x190 fs/jfs/super.c:194
generic_shutdown_super+0x13d/0x2d0 fs/super.c:751
kill_block_super+0x44/0xa0 fs/super.c:1914
deactivate_locked_super+0xbe/0x110 fs/super.c:586
cleanup_mnt+0x204/0x2a0 fs/namespace.c:1396
task_work_run+0x1d9/0x260 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x705/0x2360 kernel/exit.c:980
do_group_exit+0x22d/0x2f0 kernel/exit.c:1123
__do_sys_exit_group kernel/exit.c:1134 [inline]
__se_sys_exit_group kernel/exit.c:1132 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1132
x64_sys_call+0x18c6/0x18d0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efff695f559
Code: Unable to access opcode bytes at 0x7efff695f52f.
RSP: 002b:00007ffc3bb1d2e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007efff69f5f88 RCX: 00007efff695f559
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000002 R08: 0000000000000000 R09: 00007efff69f5f63
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc3bb1e5a0
R13: 00007efff69f5f63 R14: 000000000007265b R15: 00007ffc3bb20760
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:jfs_flush_journal+0xf2b/0xf50 fs/jfs/jfs_logmgr.c:1585
Code: e9 9e f5 ff ff e8 75 09 54 fe 48 c7 c7 00 f2 cd 8b 48 c7 c6 00 ed cd 8b ba 31 06 00 00 48 c7 c1 40 f2 cd 8b e8 b6 9d b3 fd 90 <0f> 0b e8 4e 09 54 fe bf 02 00 00 00 e8 64 ab 21 fe e9 a9 f7 ff ff
RSP: 0018:ffffc900044979c0 EFLAGS: 00010246
RAX: 0000000000000040 RBX: dffffc0000000000 RCX: d7996471a1db3100
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90004497b00 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff52000892ee9 R12: 00000000000000c7
R13: ffff88803f245a18 R14: ffff88803f245800 R15: ffff88803f245ad8
FS: 0000000000000000(0000) GS:ffff88812472f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f09e4bbc000 CR3: 000000002d7bc000 CR4: 00000000003526f0
* Struck through repros no longer work on HEAD.