INFO: task syz.3.1324:10321 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1324 state:D stack:27560 pid:10321 ppid:5770 flags:0x00004006
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
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747
blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
bdev_open_by_dev+0x77/0x100 block/bdev.c:859
setup_bdev_super+0x59/0x660 fs/super.c:1496
mount_bdev+0x1d3/0x2d0 fs/super.c:1640
legacy_get_tree+0xea/0x180 fs/fs_context.c:662
vfs_get_tree+0x8c/0x280 fs/super.c:1764
do_new_mount+0x24b/0xa40 fs/namespace.c:3386
do_mount fs/namespace.c:3726 [inline]
__do_sys_mount fs/namespace.c:3935 [inline]
__se_sys_mount+0x2e7/0x3d0 fs/namespace.c:3912
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: 0033:0x7f8501f9cdd9
RSP: 002b:00007f8502e9d028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f8502216090 RCX: 00007f8501f9cdd9
RDX: 0000200000004200 RSI: 0000200000000040 RDI: 0000200000000000
RBP: 00007f8502032d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000a18410 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8502216128 R14: 00007f8502216090 R15: 00007ffc8d0255d8
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/u4:2/38:
#0: ffff88801838b138 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff88801838b138 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1: ffffc90000aefd00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc90000aefd00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
2 locks held by kworker/u4:3/48:
#0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa9/0x140 kernel/sched/core.c:567
#1: ffffc90000b97d00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc90000b97d00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
2 locks held by kworker/u4:4/59:
#0: ffff88801838b138 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff88801838b138 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1: ffffc900015a7d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc900015a7d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
2 locks held by getty/5524:
#0: ffff88814cd190a0 (&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
2 locks held by kworker/0:7/5874:
#0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1: ffffc90004bafd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc90004bafd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
3 locks held by kworker/u4:10/6751:
#0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1: ffffc900033b7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc900033b7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#2: ffffffff8e3c2ac8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:286
1 lock held by udevd/10126:
#0: ffff8880221474c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
3 locks held by kworker/0:1/10158:
#0: ffff88823bdc6f38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff88823bdc6f38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1: ffffc9000534fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc9000534fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#2: ffff88802556e190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#2: ffff88802556e190 (&dev->mutex){....}-{3:3}, at: hub_event+0x180/0x49f0 drivers/usb/core/hub.c:5861
1 lock held by syz.3.1324/10321:
#0: ffff8880221474c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
2 locks held by syz.1.1548/11136:
#0: ffffffff8e3c2ac8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8e3c2ac8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3511
#1: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
#1: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 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 04/18/2026
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: 48 Comm: kworker/u4:3 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:deref_stack_reg+0x1c5/0x240 arch/x86/kernel/unwind_orc.c:406
Code: c1 4c 39 e0 0f 96 c0 84 c1 74 43 e8 65 bc 4b 00 49 bf 00 00 00 00 00 fc ff df 48 89 ef e8 63 08 00 00 49 89 c6 48 8b 5c 24 20 <48> 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 05 f4 a3 00
RSP: 0018:ffffc90000b974f8 EFLAGS: 00000293
RAX: 0000000000000820 RBX: ffffc90000b97668 RCX: ffff88801d271e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffc90000b97988
RBP: ffffc90000b97988 R08: ffff88801d271e00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000000 R12: ffffc90000b98000
R13: 1ffff92000172ec7 R14: 0000000000000820 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f112d9ea2f8 CR3: 0000000063349000 CR4: 00000000003506f0
Call Trace:
unwind_next_frame+0x1789/0x2970 arch/x86/kernel/unwind_orc.c:648
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
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:1316 [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:2653 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
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
vkms_vblank_simulate: vblank timer overrun