INFO: task syz.8.4257:22858 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.4257 state:D stack:23368 pid:22858 ppid:16755 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
perf_pending_task_sync kernel/events/core.c:5236 [inline]
_free_event+0x176/0xfb0 kernel/events/core.c:5242
put_event kernel/events/core.c:5370 [inline]
perf_event_release_kernel+0x7c8/0x850 kernel/events/core.c:5495
perf_release+0x3b/0x40 kernel/events/core.c:5505
__fput+0x221/0x930 fs/file_table.c:384
task_work_run+0x1d4/0x260 kernel/task_work.c:245
get_signal+0x11da/0x1390 kernel/signal.c:2679
arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2b47f9ce59
RSP: 002b:00007f2b48e3ffd8 EFLAGS: 00000202 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffff RBX: 00007f2b48215fa0 RCX: 00007f2b47f9ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000002c9a4080
RBP: 00007f2b48032e6f R08: ffffffffff600000 R09: ffffffffff600000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007f2b48216038 R14: 00007f2b48215fa0 R15: 00007ffc40452078
Showing all locks held in the system:
1 lock held by khungtaskd/28:
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by getty/5533:
#0: ffff8880312d80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000325e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
5 locks held by kworker/u4:7/17030:
#0: ffff88801a254938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff88801a254938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#1: ffffc9000452fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc9000452fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
#2: ffffffff8e3b2e50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x14c/0xbb0 net/core/net_namespace.c:606
#3: ffffffff8e3bfe48 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_delete_nets+0xd6/0x380 net/ipv4/ip_tunnel.c:1152
#4: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
#4: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004
1 lock held by syz.6.4858/25089:
#0: ffffffff8d1920e8 (bpf_event_mutex){+.+.}-{3:3}, at: perf_event_detach_bpf_prog+0x8b/0x310 kernel/trace/bpf_trace.c:2215
1 lock held by syz.4.4861/25098:
#0: ffffffff8d1920e8 (bpf_event_mutex){+.+.}-{3:3}, at: perf_event_detach_bpf_prog+0x8b/0x310 kernel/trace/bpf_trace.c:2215
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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+0xf59/0xfa0 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 16438 Comm: kworker/u4:3 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:-1 [inline]
RIP: 0010:unwind_next_frame+0x448/0x2990 arch/x86/kernel/unwind_orc.c:494
Code: 4c 8b 2c 24 0f 84 82 02 00 00 48 89 5c 24 20 4b 8d 5c a6 fc 49 39 de 0f 86 0a 14 00 00 e8 40 bd 4b 00 4c 89 f5 e9 a6 14 00 00 <4e> 8d 2c a5 f4 61 97 8e 44 29 e5 49 8d 5c ad fc 49 39 dd 76 10 e8
RSP: 0018:ffffc90003637518 EFLAGS: 00000202
RAX: ffffffff813b2686 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffff88802acbda00 RSI: 0000000000011089 RDI: 000000000001108a
RBP: 000000000001108a R08: ffffc900036376b0 R09: 0000000000000009
R10: 0000000000000004 R11: 0000000000000000 R12: 0000000000011089
R13: 000000000009c001 R14: 00000000000058d5 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c354554 CR3: 0000000075d73000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
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_save_free_info+0x28/0x40 mm/kasan/generic.c:522
____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1811 [inline]
slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837
slab_free mm/slub.c:3830 [inline]
__kmem_cache_free+0xba/0x1f0 mm/slub.c:3843
skb_kfree_head net/core/skbuff.c:946 [inline]
skb_free_head net/core/skbuff.c:958 [inline]
skb_release_data+0x609/0x7f0 net/core/skbuff.c:988
skb_release_all net/core/skbuff.c:1054 [inline]
__kfree_skb net/core/skbuff.c:1068 [inline]
consume_skb+0xb2/0x110 net/core/skbuff.c:1284
nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline]
nsim_dev_trap_report_work+0x723/0xa90 drivers/net/netdevsim/dev.c:851
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730
worker_thread+0xa5e/0xfe0 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