syzbot

INFO: task syz.3.48:6251 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc2-syzkaller-00269-g11313e2f7812 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.48        state:D stack:25160 pid:6251  tgid:6250  ppid:5825   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 jfs_flush_journal+0x716/0xed0 fs/jfs/jfs_logmgr.c:1564
 jfs_sync_fs+0x7d/0xa0 fs/jfs/super.c:649
 __iterate_supers+0x13a/0x250 fs/super.c:924
 ksys_sync+0xb2/0x150 fs/sync.c:104
 __ia32_sys_sync+0xe/0x20 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efe4418e929
RSP: 002b:00007efe45062038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007efe443b5fa0 RCX: 00007efe4418e929
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007efe443b5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007efe443b5fa0 R15: 00007ffe67900d18
 </TASK>

Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
 #0: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
 #0: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:998
1 lock held by khungtaskd/31:
 #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5584:
 #0: ffff88814c27a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000361c2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by syz-executor/5832:
 #0: ffffffff8e87e488 (bio_slab_lock){+.+.}-{4:4}, at: bio_put_slab block/bio.c:140 [inline]
 #0: ffffffff8e87e488 (bio_slab_lock){+.+.}-{4:4}, at: bioset_exit+0x44a/0x690 block/bio.c:1758
 #1: ffffffff8e144780 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3782
1 lock held by syz.3.48/6251:
 #0: ffff8880570200e0 (&type->s_umount_key#68){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
 #0: ffff8880570200e0 (&type->s_umount_key#68){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
2 locks held by syz.3.48/6256:
 #0: ffff88807b9ad470 (&fc->uapi_mutex){+.+.}-{4:4}, at: __do_sys_fsconfig fs/fsopen.c:465 [inline]
 #0: ffff88807b9ad470 (&fc->uapi_mutex){+.+.}-{4:4}, at: __se_sys_fsconfig+0x758/0x8d0 fs/fsopen.c:344
 #1: ffff8880570200e0 (&type->s_umount_key#68){++++}-{4:4}, at: vfs_cmd_reconfigure fs/fsopen.c:261 [inline]
 #1: ffff8880570200e0 (&type->s_umount_key#68){++++}-{4:4}, at: vfs_fsconfig_locked+0x169/0x320 fs/fsopen.c:291
1 lock held by syz.1.101/6647:
 #0: ffff8880570200e0 (&type->s_umount_key#68){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
 #0: ffff8880570200e0 (&type->s_umount_key#68){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
1 lock held by syz.5.190/7460:
 #0: ffff8880570200e0 (&type->s_umount_key#68){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
 #0: ffff8880570200e0 (&type->s_umount_key#68){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
1 lock held by syz-executor/7768:
 #0: ffffffff8e87e488 (bio_slab_lock){+.+.}-{4:4}, at: bio_put_slab block/bio.c:140 [inline]
 #0: ffffffff8e87e488 (bio_slab_lock){+.+.}-{4:4}, at: bioset_exit+0x44a/0x690 block/bio.c:1758
1 lock held by syz.3.296/8446:
1 lock held by rm/8456:

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc2-syzkaller-00269-g11313e2f7812 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:470
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 8445 Comm: syz.3.296 Not tainted 6.16.0-rc2-syzkaller-00269-g11313e2f7812 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0033:0x7f3084e6e98b
Code: c5 81 e5 ff 0f 00 00 48 31 d5 80 3d d6 36 34 00 00 0f 84 a8 00 00 00 4c 89 f6 48 8b 0d b6 36 34 00 31 c0 48 81 ce ff ff ff 3f <48> 3b 34 c1 0f 84 3b 01 00 00 48 83 c0 01 48 83 f8 04 75 ec 31 f6
RSP: 002b:00007fff60b1afb0 EFLAGS: 00000286
RAX: 0000000000000000 RBX: 00007f3085ce5720 RCX: 000000110f230000
RDX: ffffffff8173a9f9 RSI: ffffffffbfffffff RDI: 0000000000000000
RBP: ffffffff8173a0dc R08: 00007f30851b6038 R09: 00007f30851a2000
R10: 00007f30845ff008 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff8173a9f9 R15: 0000000000061e11
FS:  00005555559f7500 GS:  0000000000000000