INFO: task syz-executor:5768 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:21128 pid:5768 ppid:1 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
wb_wait_for_completion+0x166/0x290 fs/fs-writeback.c:192
sync_inodes_sb+0x1bc/0x9e0 fs/fs-writeback.c:2772
sync_filesystem+0x171/0x220 fs/sync.c:64
generic_shutdown_super+0x6f/0x2b0 fs/super.c:666
kill_block_super+0x44/0x90 fs/super.c:1660
deactivate_locked_super+0x97/0x100 fs/super.c:481
cleanup_mnt+0x429/0x4c0 fs/namespace.c:1259
task_work_run+0x1ce/0x250 kernel/task_work.c:239
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0x90b/0x23c0 kernel/exit.c:883
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
__do_sys_exit_group kernel/exit.c:1035 [inline]
__se_sys_exit_group kernel/exit.c:1033 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f128278f749
RSP: 002b:00007ffc95ac7898 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f1282813ddd RCX: 00007f128278f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 000000000000000c R08: 00007ffc95ac5636 R09: 00007ffc95ac8b50
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc95ac8b50
R13: 00007f1282813d7d R14: 000055557fe644a8 R15: 00007ffc95ac9c20
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
3 locks held by kworker/0:2/787:
#0: ffff88801a27dd38 ((wq_completion)pm){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a27dd38 ((wq_completion)pm){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90003a47d00 ((work_completion)(&hcd->wakeup_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90003a47d00 ((work_completion)(&hcd->wakeup_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff888024ed7190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#2: ffff888024ed7190 (&dev->mutex){....}-{3:3}, at: hub_event+0x185/0x49c0 drivers/usb/core/hub.c:5861
2 locks held by getty/5528:
#0: ffff88802ce2f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
2 locks held by syz-executor/5768:
#0: ffff888021e940e0 (&type->s_umount_key#63){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline]
#0: ffff888021e940e0 (&type->s_umount_key#63){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff888021e940e0 (&type->s_umount_key#63){++++}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
#1: ffff88814175e7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
#1: ffff88814175e7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a0/0x9e0 fs/fs-writeback.c:2770
5 locks held by kworker/u4:12/5901:
1 lock held by segctord/5968:
1 lock held by syz.4.291/7446:
#0: ffff888021e940e0 (&type->s_umount_key#63){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888021e940e0 (&type->s_umount_key#63){++++}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117
1 lock held by syz-executor/7663:
#0: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
#0: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x448/0x830 kernel/rcu/tree_exp.h:1004
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 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+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf41/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 59 Comm: kworker/u4:4 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:skb_put+0xe/0x210 net/core/skbuff.c:2436
Code: 08 9e 28 f9 0f 0b e8 01 9e 28 f9 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 <48> 83 ec 10 41 89 f7 49 89 fe 48 bb 00 00 00 00 00 fc ff df e8 c9
RSP: 0018:ffffc900015a7a98 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88801e6c0000
RDX: 0000000000000000 RSI: 000000000000000e RDI: ffff88802ba47500
RBP: ffff88805ca5d1d8 R08: ffff88807d20aee3 R09: 1ffff1100fa415dc
R10: dffffc0000000000 R11: ffffed100fa415dd R12: dffffc0000000000
R13: ffff88802ba47500 R14: ffff8880304d6568 R15: 0000000000000060
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556de0d5c8 CR3: 0000000076a05000 CR4: 00000000003506f0
Call Trace:
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:754 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x328/0xb00 drivers/net/netdevsim/dev.c:851
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293