INFO: task syz-executor:5766 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:21424 pid:5766 ppid:1 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
wb_wait_for_completion+0x173/0x2a0 fs/fs-writeback.c:192
sync_inodes_sb+0x1c9/0xa10 fs/fs-writeback.c:2778
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+0x43b/0x4d0 fs/namespace.c:1259
task_work_run+0x1d4/0x260 kernel/task_work.c:245
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0x95a/0x2460 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:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f128a59bf79
RSP: 002b:00007ffede844938 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f128a631c9b RCX: 00007f128a59bf79
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 000000000000000c R08: 0000000000000000 R09: 00007f128a631c3b
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffede845bf0
R13: 00007f128a631c3b R14: 000055556bfff4e8 R15: 00007ffede846cc0
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
3 locks held by kworker/0:2/1190:
#0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
#1: ffffc90004b0fd00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90004b0fd00 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
#2: ffffffff8d137978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
#2: ffffffff8d137978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004
2 locks held by kworker/u4:9/4805:
2 locks held by getty/5522:
#0: ffff8880317120a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217
4 locks held by udevd/5754:
#0: ffff888069b21540 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb1/0xd50 fs/seq_file.c:182
#1: ffff888026cde488 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x5c/0x410 fs/kernfs/file.c:172
#2: ffff88802eab0008 (kn->active#18){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802eab0008 (kn->active#18){.+.+}-{0:0}, at: kernfs_seq_start+0xb2/0x410 fs/kernfs/file.c:173
#3: ffff88801af90190 (&dev->mutex){....}-{3:3}, at: device_lock_interruptible include/linux/device.h:1000 [inline]
#3: ffff88801af90190 (&dev->mutex){....}-{3:3}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
2 locks held by syz-executor/5766:
#0: ffff88805a04a0e0 (&type->s_umount_key#71){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
#0: ffff88805a04a0e0 (&type->s_umount_key#71){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff88805a04a0e0 (&type->s_umount_key#71){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
#1: ffff8880219327d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
#1: ffff8880219327d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1ad/0xa10 fs/fs-writeback.c:2776
2 locks held by kworker/0:3/5798:
#0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
#1: ffffc900045bfd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900045bfd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
5 locks held by kworker/1:7/5859:
#0: ffff888019aac938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888019aac938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
#1: ffffc9000495fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000495fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
#2: ffff8880251e4190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#2: ffff8880251e4190 (&dev->mutex){....}-{3:3}, at: hub_event+0x180/0x49f0 drivers/usb/core/hub.c:5861
#3: ffff88801af90190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#3: ffff88801af90190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x89/0x420 drivers/base/dd.c:1005
#4: ffff888144b21160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#4: ffff888144b21160 (&dev->mutex){....}-{3:3}, at: __device_attach+0x89/0x420 drivers/base/dd.c:1005
3 locks held by segctord/6294:
#0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa9/0x140 kernel/sched/core.c:567
#1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline]
#1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2176/0x45a0 kernel/sched/core.c:6695
#2: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: nilfs_segctor_wakeup+0x37/0x330 fs/nilfs2/segment.c:2270
4 locks held by syz-executor/8398:
#0: ffff8880261e4e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:521 [inline]
#0: ffff8880261e4e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x212/0x500 net/bluetooth/hci_core.c:2709
#1: ffff8880261e40b8 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x4c9/0xfa0 net/bluetooth/hci_sync.c:5273
#2: ffffffff8e52d768 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2011 [inline]
#2: ffffffff8e52d768 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa1/0x220 net/bluetooth/hci_conn.c:2540
#3: ffff8880241ceb38 (&conn->lock#2){+.+.}-{3:3}, at: l2cap_conn_del+0x70/0x660 net/bluetooth/l2cap_core.c:1763
1 lock held by syz.5.524/8734:
#0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3511
1 lock held by syz.4.526/8744:
#0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3511
1 lock held by dhcpcd/8759:
#0: ffff88801f71c130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1780 [inline]
#0: ffff88801f71c130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcc0 net/packet/af_packet.c:3258
=============================================
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 02/12/2026
Call Trace:
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a6/0x3e0 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+0xf3d/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: 1106 Comm: kworker/u4:7 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:stack_trace_consume_entry+0x0/0x270 kernel/stacktrace.c:83
Code: 48 8b 0c 25 28 00 00 00 48 3b 4c 24 78 75 09 48 8d 65 f0 5b 41 5e 5d c3 e8 4d a4 0e 09 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 18 48 ba 00 00
RSP: 0018:ffffc9000475f620 EFLAGS: 00000286
RAX: ffffffff8132a3ba RBX: ffffc9000475f6e0 RCX: ffff888023d4bc00
RDX: 0000000000000000 RSI: ffffffff81de67fc RDI: ffffc9000475f6e0
RBP: ffffc9000475f6b0 R08: ffff888023d4bc00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000000 R12: ffffffff81de67fc
R13: 00000000000000f0 R14: ffffffff8175b740 R15: ffffc9000475f628
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005615e69157d0 CR3: 000000000cf32000 CR4: 00000000003506f0
Call Trace:
arch_stack_walk+0x138/0x190 arch/x86/kernel/stacktrace.c:27
stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:329
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767
slab_alloc_node mm/slub.c:3495 [inline]
kmem_cache_alloc_node+0x14c/0x320 mm/slub.c:3540
__alloc_skb+0x103/0x2c0 net/core/skbuff.c:643
alloc_skb include/linux/skbuff.h:1284 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x293/0xb00 drivers/net/netdevsim/dev.c:851
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa5d/0x15d0 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