INFO: task syz.0.20:5130 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.20 state:D stack:25512 pid: 5130 ppid: 4826 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x97/0x280 kernel/time/timer.c:1890
do_wait_for_common+0x29a/0x440 kernel/sched/completion.c:85
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x48/0x60 kernel/sched/completion.c:138
kthread_stop+0x16e/0x540 kernel/kthread.c:666
ext4_stop_mmpd+0x43/0xb0 fs/ext4/mmp.c:263
ext4_fill_super+0x660b/0x9a60 fs/ext4/super.c:5088
mount_bdev+0x287/0x3c0 fs/super.c:1400
legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
vfs_get_tree+0x88/0x270 fs/super.c:1530
do_new_mount+0x24a/0xa40 fs/namespace.c:3034
do_mount fs/namespace.c:3377 [inline]
__do_sys_mount fs/namespace.c:3585 [inline]
__se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3562
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f147fe5e90a
RSP: 002b:00007f147f0cde68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f147f0cdef0 RCX: 00007f147fe5e90a
RDX: 0000400000000040 RSI: 0000400000000000 RDI: 00007f147f0cdeb0
RBP: 0000400000000040 R08: 00007f147f0cdef0 R09: 0000000003010008
R10: 0000000003010008 R11: 0000000000000246 R12: 0000400000000000
R13: 00007f147f0cdeb0 R14: 0000000000000538 R15: 0000400000000340
Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0: ffffffff8c11c720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3949:
#0: ffff88802c723098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
3 locks held by kworker/1:16/4710:
#0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc9000314fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffff8880592b7240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x271/0x3240 drivers/net/netdevsim/fib.c:1480
1 lock held by syz.0.20/5130:
#0: ffff8880791bc0e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.1.28/5173:
#0: ffff888077c2e0e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.2.29/5195:
#0: ffff88807be740e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.3.32/5231:
#0: ffff88807e5ea0e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.4.36/5268:
#0: ffff8880257640e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.5.44/5318:
#0: ffff88814c5120e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.6.52/5365:
#0: ffff88801f00a0e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.7.62/5426:
#0: ffff88802b5b20e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.8.63/5455:
#0: ffff8880791b60e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.9.64/5485:
#0: ffff8880683b20e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe0f/0xe50 kernel/hung_task.c:369
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 145 Comm: kworker/u4:2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: 0x0 (phy10)
RIP: 0010:lock_is_held_type+0x4c/0x190 kernel/locking/lockdep.c:5659
Code: 3d 6c 7f c7 03 00 0f 84 03 01 00 00 65 8b 05 5b 8f 60 76 85 c0 0f 85 f4 00 00 00 65 48 8b 1d cb 85 60 76 83 bb ec 0a 00 00 00 <0f> 85 df 00 00 00 41 89 f7 49 89 fe 48 c7 04 24 00 00 00 00 9c 8f
RSP: 0018:ffffc9000174fbc0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff88801b9b3b80 RCX: ffff88801b9b3b80
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff888016879818
RBP: 00000000ffffffff R08: dffffc0000000000 R09: ffff888017fded10
R10: ffffed1002ffbda5 R11: 1ffff11002ffbda2 R12: 00000000ffffffff
R13: dffffc0000000000 R14: 1ffff1100b6f0a02 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f684bdc75a0 CR3: 0000000022b92000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_is_held include/linux/lockdep.h:287 [inline]
put_pwq kernel/workqueue.c:1134 [inline]
pwq_dec_nr_in_flight+0x18f/0x450 kernel/workqueue.c:1233
process_one_work+0xb1b/0x1000 kernel/workqueue.c:2353
worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287