INFO: task syz.4.8500:3851 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.8500 state:D stack:26400 pid:3851 ppid:3432 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
perf_pending_task_sync kernel/events/core.c:5031 [inline]
_free_event+0x171/0x10a0 kernel/events/core.c:5037
put_event kernel/events/core.c:5162 [inline]
perf_event_release_kernel+0x832/0x8c0 kernel/events/core.c:5287
perf_release+0x37/0x40 kernel/events/core.c:5297
__fput+0x22c/0x920 fs/file_table.c:320
task_work_run+0x1ca/0x250 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0x93e/0x2400 kernel/exit.c:880
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
get_signal+0x1272/0x1350 kernel/signal.c:2871
arch_do_signal_or_restart+0xb7/0x1240 arch/x86/kernel/signal.c:871
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:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd13698f749
RSP: 002b:00007fd134bf5fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: fffffffffffffffc RBX: 00007fd136be5fa0 RCX: 00007fd13698f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000126400
RBP: 00007fd136a13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fd136be6038 R14: 00007fd136be5fa0 R15: 00007fff869941d8
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8c92bab0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8c92c2d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
2 locks held by ksoftirqd/0/15:
1 lock held by khungtaskd/28:
#0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by getty/4029:
#0: ffff88814cdb2098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
3 locks held by kworker/0:3/4372:
#0: ffff88814c766938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc900046f7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4131
6 locks held by kworker/u4:56/21801:
#0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc90004c37d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8db2e6d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594
#3: ffff8880629e52f8 (&devlink->lock_key#65){+.+.}-{3:3}, at: devlink_pernet_pre_exit+0xf8/0x270 net/devlink/leftover.c:12500
#4: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x3b/0x150 drivers/net/netdevsim/netdev.c:381
#5: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#5: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962
4 locks held by kworker/u4:12/29922:
#0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc90003b2fd00 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffff88806a3787c8 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: wiphy_lock include/net/cfg80211.h:5639 [inline]
#2: ffff88806a3787c8 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: cfg80211_wiphy_work+0x31/0x260 net/wireless/core.c:420
#3: ffff88806a37aaf8 (&local->mtx){+.+.}-{3:3}, at: ieee80211_scan_work+0x51/0x1bc0 net/mac80211/scan.c:1079
2 locks held by kworker/1:7/3498:
#0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc90003cafd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
4 locks held by kworker/u4:1/3583:
#0: ffff88806a321938 ((wq_completion)phy6){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc900043bfd00 ((work_completion)(&sdata->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffff888027cc0d40 (&wdev->mtx){+.+.}-{3:3}, at: sdata_lock net/mac80211/ieee80211_i.h:1113 [inline]
#2: ffff888027cc0d40 (&wdev->mtx){+.+.}-{3:3}, at: ieee80211_ibss_work+0xa0/0x10b0 net/mac80211/ibss.c:1680
#3: ffff88806a37aaf8 (&local->mtx){+.+.}-{3:3}, at: ieee80211_request_ibss_scan+0x76/0x850 net/mac80211/scan.c:1196
3 locks held by kworker/u4:5/3830:
#0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc90004eafd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#2: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962
2 locks held by syz.3.9181/6312:
#0: ffffffff8db2e6d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:504
#1: ffffffff8c930cc0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x600 kernel/rcu/tree.c:4023
1 lock held by syz.5.9197/6377:
#0: ffffffff8c9801a8 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239
1 lock held by syz.7.9198/6379:
#0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3492
1 lock held by syz.6.9200/6383:
#0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
1 lock held by syz.6.9200/6384:
#0: ffffffff8c972348 (tracepoints_mutex){+.+.}-{3:3}, at: tracepoint_probe_register_prio_may_exist+0x40/0x90 kernel/tracepoint.c:478
1 lock held by syz.6.9200/6387:
#0: ffffffff8c972348 (tracepoints_mutex){+.+.}-{3:3}, at: tracepoint_probe_register_prio_may_exist+0x40/0x90 kernel/tracepoint.c:478
=============================================
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 10/25/2025
Call Trace:
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 21 Comm: ksoftirqd/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:check_preemption_disabled+0x6/0x110 lib/smp_processor_id.c:13
Code: 89 f6 e8 cd 38 1e fa e9 6e ff ff ff 00 00 cc cc 00 00 cc cc 48 c7 c7 c0 f8 be 8a 48 c7 c6 00 f9 be 8a eb 00 55 41 57 41 56 53 <48> 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 65 8b 05 41
RSP: 0018:ffffc900001b6ab8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff888017742898 RCX: 47c2b15ed533fd00
RDX: dffffc0000000000 RSI: ffffffff8a6c1780 RDI: ffffffff8abef920
RBP: ffffc900001b6b98 R08: ffff88823b400000 R09: 0000000000000001
R10: 00000000a09fff28 R11: 1ffff92000036d0f R12: ffff888017742938
R13: 0000000000000003 R14: 1ffff11002ee8513 R15: ffff888017742880
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efe23fb6ad8 CR3: 0000000023ffc000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline]
lockdep_hardirqs_on_prepare+0x3fc/0x760 kernel/locking/lockdep.c:4316
trace_hardirqs_on+0x34/0x40 kernel/trace/trace_preemptirq.c:49
kasan_quarantine_put+0xd4/0x220 mm/kasan/quarantine.c:242
kasan_slab_free include/linux/kasan.h:177 [inline]
slab_free_hook mm/slub.c:1729 [inline]
slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1755
slab_free mm/slub.c:3687 [inline]
kmem_cache_free+0xf7/0x290 mm/slub.c:3709
skb_release_all net/core/skbuff.c:854 [inline]
__kfree_skb net/core/skbuff.c:870 [inline]
kfree_skb_reason+0x133/0x370 net/core/skbuff.c:893
kfree_skb include/linux/skbuff.h:1220 [inline]
ip6_mc_input+0xa7a/0xc70 net/ipv6/ip6_input.c:589
ip_sabotage_in+0x1f0/0x270 net/bridge/br_netfilter_hooks.c:1001
nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
nf_hook_slow+0xb9/0x200 net/netfilter/core.c:614
nf_hook include/linux/netfilter.h:257 [inline]
NF_HOOK+0x200/0x390 include/linux/netfilter.h:300
__netif_receive_skb_one_core net/core/dev.c:5581 [inline]
__netif_receive_skb+0xcc/0x290 net/core/dev.c:5695
netif_receive_skb_internal net/core/dev.c:5781 [inline]
netif_receive_skb+0x1d4/0x7e0 net/core/dev.c:5840
NF_HOOK+0x96/0x370 include/linux/netfilter.h:302
br_handle_frame_finish+0x12e8/0x1760 net/bridge/br_input.c:204
br_nf_hook_thresh+0x3b2/0x480 net/bridge/br_netfilter_hooks.c:1184
br_nf_pre_routing_finish_ipv6+0x9e1/0xda0 net/bridge/br_netfilter_ipv6.c:-1
NF_HOOK include/linux/netfilter.h:302 [inline]
br_nf_pre_routing_ipv6+0x349/0x670 net/bridge/br_netfilter_ipv6.c:243
nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:260 [inline]
br_handle_frame+0x906/0x1320 net/bridge/br_input.c:406
__netif_receive_skb_core+0xfc5/0x3840 net/core/dev.c:5475
__netif_receive_skb_one_core net/core/dev.c:5579 [inline]
__netif_receive_skb+0x74/0x290 net/core/dev.c:5695
process_backlog+0x37c/0x6e0 net/core/dev.c:6023
__napi_poll+0xc0/0x460 net/core/dev.c:6590
napi_poll net/core/dev.c:6657 [inline]
net_rx_action+0x5b1/0xad0 net/core/dev.c:6771
handle_softirqs+0x2a1/0x920 kernel/softirq.c:596
run_ksoftirqd+0x98/0xf0 kernel/softirq.c:968
smpboot_thread_fn+0x64a/0xa40 kernel/smpboot.c:164
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295