INFO: task syz.0.2086:11056 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2086 state:D stack:23568 pid:11056 ppid:4274 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
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+0x83e/0x8d0 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+0x1d0/0x260 kernel/task_work.c:203
get_signal+0x11a6/0x1350 kernel/signal.c:2648
arch_do_signal_or_restart+0xc4/0x1350 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:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1ad2f9c819
RSP: 002b:00007f1ad3df0fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: fffffffffffffffc RBX: 00007f1ad3215fa0 RCX: 00007f1ad2f9c819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000041980000
RBP: 00007f1ad3032c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f1ad3216038 R14: 00007f1ad3215fa0 R15: 00007fff9dd5d048
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2df30 (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: ffffffff8cb2e750 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
#0: ffffffff8cb2d5a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2d5a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2d5a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by kworker/1:2/129:
#0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90002dd7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
2 locks held by getty/4025:
#0: ffff88803016b098 (&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+0x429/0x1390 drivers/tty/n_tty.c:2198
2 locks held by kworker/u4:19/10740:
#0: ffff8880b8f3ab18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:538
#1: ffffc900057f7d00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
3 locks held by kworker/u4:21/10743:
#0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90005837d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffffffff8dd46ea8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263
5 locks held by kworker/u4:22/10746:
#0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90005857d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffffffff8dd39fd0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:594
#3: ffff8880752712f8 (&devlink->lock_key#2){+.+.}-{3:3}, at: devlink_pernet_pre_exit+0x104/0x280 net/devlink/leftover.c:12502
#4: ffffffff8cb33140 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x600 kernel/rcu/tree.c:4023
2 locks held by kworker/u4:23/10748:
#0: ffff8880b8f3ab18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:538
#1: ffffffff8cb2d5a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#1: ffffffff8cb2d5a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#1: ffffffff8cb2d5a0 (rcu_read_lock){....}-{1:2}, at: do_perf_sw_event kernel/events/core.c:9736 [inline]
#1: ffffffff8cb2d5a0 (rcu_read_lock){....}-{1:2}, at: ___perf_sw_event+0x180/0x6e0 kernel/events/core.c:9774
3 locks held by kworker/u4:28/10758:
#0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90005917d00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffffffff8cb33278 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#2: ffffffff8cb33278 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962
5 locks held by syz-executor/14449:
#0: ffff88807dca8460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x26b/0xa30 fs/read_write.c:580
#1: ffff888034403088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343
#2: ffff88801f302008 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88801f302008 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8d656348 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd4/0x360 drivers/net/netdevsim/bus.c:209
#4: ffff8880752700e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline]
#4: ffff8880752700e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1080 [inline]
#4: ffff8880752700e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb2/0x850 drivers/base/dd.c:1283
1 lock held by syz.3.3064/14474:
#0: ffffffff8cb8c1c8 (bpf_event_mutex){+.+.}-{3:3}, at: perf_event_detach_bpf_prog+0x87/0x310 kernel/trace/bpf_trace.c:2178
2 locks held by syz.3.3064/14475:
#0: ffffffff8dd46ea8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8dd46ea8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6147
#1: ffffffff8cb33278 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#1: ffffffff8cb33278 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3c0/0x890 kernel/rcu/tree_exp.h:962
1 lock held by syz.5.3062/14478:
#0: ffffffff8cb8c1c8 (bpf_event_mutex){+.+.}-{3:3}, at: perf_event_detach_bpf_prog+0x87/0x310 kernel/trace/bpf_trace.c:2178
1 lock held by syz.5.3062/14481:
#0: ffffffff8dd46ea8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8dd46ea8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6147
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3e6/0x460 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4310 Comm: kworker/0:5 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: mld mld_ifc_work
RIP: 0010:unwind_done arch/x86/include/asm/unwind.h:50 [inline]
RIP: 0010:__unwind_start+0x5c9/0x740 arch/x86/kernel/unwind_orc.c:714
Code: e8 fc 3c 9a 00 48 8b 44 24 10 49 39 04 24 0f 87 14 fb ff ff 48 89 df e8 65 d7 ff ff 48 be 00 00 00 00 00 fc ff df 48 8b 04 24 <0f> b6 04 30 84 c0 75 0e 83 3b 00 0f 85 4a ff ff ff e9 e8 fa ff ff
RSP: 0018:ffffc90004467108 EFLAGS: 00000282
RAX: 1ffff9200088ce2d RBX: ffffc90004467168 RCX: 0000000000000201
RDX: ffffc90004467101 RSI: dffffc0000000000 RDI: 00000000ffffffff
RBP: 1ffff9200088ce2e R08: ffffc900044671f0 R09: ffffc900044671b8
R10: dffffc0000000000 R11: fffff5200088ce39 R12: ffffc900044671a0
R13: ffffc90004467178 R14: 1ffff9200088ce2f R15: ffffc90004467170
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33b0fff8 CR3: 000000007d102000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xda/0x140 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
__kasan_slab_alloc+0x6b/0x80 mm/kasan/common.c:329
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737
slab_alloc_node mm/slub.c:3359 [inline]
kmem_cache_alloc_node+0x14d/0x320 mm/slub.c:3404
__alloc_skb+0xfc/0x7e0 net/core/skbuff.c:505
alloc_skb include/linux/skbuff.h:1303 [inline]
nlmsg_new include/net/netlink.h:991 [inline]
__neigh_notify+0x15c/0x300 net/core/neighbour.c:3514
neigh_cleanup_and_release+0xc6/0x2e0 net/core/neighbour.c:102
neigh_del net/core/neighbour.c:226 [inline]
neigh_remove_one+0x5ed/0x700 net/core/neighbour.c:247
neigh_forced_gc net/core/neighbour.c:280 [inline]
neigh_alloc net/core/neighbour.c:486 [inline]
___neigh_create+0x46a/0x24c0 net/core/neighbour.c:649
ip6_finish_output2+0x1525/0x15d0 net/ipv6/ip6_output.c:129
dst_output include/net/dst.h:453 [inline]
NF_HOOK+0x161/0x4a0 include/linux/netfilter.h:302
mld_sendpack+0x83b/0xdc0 net/ipv6/mcast.c:1825
mld_send_cr net/ipv6/mcast.c:2126 [inline]
mld_ifc_work+0x836/0xb40 net/ipv6/mcast.c:2658
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295