INFO: task syz.5.1708:10990 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.1708 state:D stack:23504 pid:10990 ppid: 6414 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
perf_pending_task_sync+0x13c/0x1c0 kernel/events/core.c:5127
_free_event+0x34/0xe60 kernel/events/core.c:5133
put_event kernel/events/core.c:5258 [inline]
perf_event_release_kernel+0x83e/0x8d0 kernel/events/core.c:5383
perf_release+0x37/0x40 kernel/events/core.c:5393
__fput+0x234/0x930 fs/file_table.c:311
task_work_run+0x125/0x1a0 kernel/task_work.c:188
get_signal+0x1222/0x12c0 kernel/signal.c:2672
arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f9a0996f819
RSP: 002b:00007f9a07bc8fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: fffffffffffffffc RBX: 00007f9a09be8fa0 RCX: 00007f9a0996f819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040020000
RBP: 00007f9a09a05c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f9a09be9038 R14: 00007f9a09be8fa0 R15: 00007ffc3cc50fa8
Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3943:
#0: ffff88802c206098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158
3 locks held by kworker/0:6/4227:
#0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
#1: ffffc900031bfd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
#2: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
#2: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845
3 locks held by kworker/u4:19/5902:
#0: ffff888016c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
#1: ffffc90003eb7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
#2: ffffffff8d43cb48 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251
4 locks held by kworker/u4:25/7857:
#0: ffff888016dcd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
#1: ffffc90003ee7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
#2: ffffffff8d430c50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:589
#3: ffffffff8d43cb48 (rtnl_mutex){+.+.}-{3:3}, at: netdev_run_todo+0x88f/0xa70 net/core/dev.c:10722
1 lock held by syz.4.2655/15332:
#0: ffffffff8d43cb48 (rtnl_mutex){+.+.}-{3:3}, at: netdev_run_todo+0x88f/0xa70 net/core/dev.c:10722
1 lock held by syz.7.2661/15352:
#0: ffffffff8d43cb48 (rtnl_mutex){+.+.}-{3:3}, at: netdev_run_todo+0x88f/0xa70 net/core/dev.c:10722
2 locks held by syz.9.2665/15374:
#0: ffffffff8d43cb48 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline]
#0: ffffffff8d43cb48 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3440
#1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
2 locks held by syz.8.2668/15387:
#0: ffffffff8cccf5e8 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0xdc/0x1a80 drivers/net/ppp/ppp_generic.c:738
#1: ffffffff8d43cb48 (rtnl_mutex){+.+.}-{3:3}, at: ppp_create_interface drivers/net/ppp/ppp_generic.c:3359 [inline]
#1: ffffffff8d43cb48 (rtnl_mutex){+.+.}-{3:3}, at: ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:1069 [inline]
#1: ffffffff8d43cb48 (rtnl_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x689/0x1a80 drivers/net/ppp/ppp_generic.c:742
1 lock held by syz.8.2668/15388:
#0: ffffffff8cccf5e8 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0xdc/0x1a80 drivers/net/ppp/ppp_generic.c:738
2 locks held by syz.8.2668/15389:
#0: ffffffff8d430c50 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:499
#1: ffffffff8d43cb48 (rtnl_mutex){+.+.}-{3:3}, at: register_nexthop_notifier+0x84/0x240 net/ipv4/nexthop.c:3620
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 27 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+0x188/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe0f/0xe50 kernel/hung_task.c:369
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 14 Comm: ksoftirqd/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:kasan_get_free_meta+0x7/0x20 mm/kasan/common.c:244
Code: 1f 40 00 48 63 8f bc 00 00 00 48 8d 04 0e 48 85 c9 48 0f 44 c1 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 63 8f c0 00 00 00 <48> 8d 14 0e 31 c0 48 81 f9 ff ff ff 7f 48 0f 45 c2 c3 0f 1f 80 00
RSP: 0018:ffffc90000d363d8 EFLAGS: 00000a02
RAX: dffffc0000000000 RBX: ffffc90000d36480 RCX: 0000000000000000
RDX: 0000000000000800 RSI: ffff8880750b9a00 RDI: ffff88801bbe4140
RBP: ffffc90000d36478 R08: ffffffff8100480f R09: 0000000000000003
R10: 0000000023a65017 R11: 0000000081753504 R12: ffff88801bbe4140
R13: ffff8880750b9a00 R14: ffff88801bbe4140 R15: ffff8880750b9a00
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4e5de28158 CR3: 000000003d8c3000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
kasan_quarantine_put+0x12/0x220 mm/kasan/quarantine.c:187
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:1710 [inline]
slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736
slab_free mm/slub.c:3504 [inline]
kmem_cache_free+0x8f/0x210 mm/slub.c:3520
kfree_skb include/linux/skbuff.h:1118 [inline]
packet_rcv_fanout+0xdc/0x640 net/packet/af_packet.c:1485
dev_queue_xmit_nit+0xa69/0xb00 net/core/dev.c:2386
xmit_one net/core/dev.c:3657 [inline]
dev_hard_start_xmit+0x13e/0x7e0 net/core/dev.c:3678
__dev_queue_xmit+0x1a9b/0x2f80 net/core/dev.c:4305
br_dev_queue_push_xmit+0x692/0x850 net/bridge/br_forward.c:53
NF_HOOK+0x5c7/0x640 include/linux/netfilter.h:302
br_nf_post_routing+0x915/0xcb0 net/bridge/br_netfilter_hooks.c:955
nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
nf_hook_slow+0xb9/0x200 net/netfilter/core.c:584
nf_hook include/linux/netfilter.h:257 [inline]
NF_HOOK+0x1f3/0x380 include/linux/netfilter.h:300
br_forward_finish+0x74/0x80 net/bridge/br_forward.c:66
br_nf_hook_thresh net/bridge/br_netfilter_hooks.c:1155 [inline]
br_nf_forward_finish+0x9bb/0xd50 net/bridge/br_netfilter_hooks.c:662
NF_HOOK+0x5c7/0x640 include/linux/netfilter.h:302
br_nf_forward_ip+0xc5c/0x10a0 net/bridge/br_netfilter_hooks.c:732
nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
nf_hook_slow+0xb9/0x200 net/netfilter/core.c:584
nf_hook include/linux/netfilter.h:257 [inline]
NF_HOOK+0x1f3/0x380 include/linux/netfilter.h:300
__br_forward+0x433/0x610 net/bridge/br_forward.c:115
br_handle_frame_finish+0xfbd/0x1270 net/bridge/br_input.c:180
br_nf_hook_thresh+0x3c9/0x4a0 net/bridge/br_netfilter_hooks.c:1155
br_nf_pre_routing_finish_ipv6+0x9c2/0xc90 net/bridge/br_netfilter_ipv6.c:-1
NF_HOOK include/linux/netfilter.h:302 [inline]
br_nf_pre_routing_ipv6+0x355/0x680 net/bridge/br_netfilter_ipv6.c:237
nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:242 [inline]
br_handle_frame+0xec7/0x10e0 net/bridge/br_input.c:384
__netif_receive_skb_core+0xfef/0x3690 net/core/dev.c:5445
__netif_receive_skb_one_core net/core/dev.c:5549 [inline]
__netif_receive_skb+0x74/0x290 net/core/dev.c:5665
process_backlog+0x370/0x790 net/core/dev.c:6542
__napi_poll+0xc0/0x430 net/core/dev.c:7101
napi_poll net/core/dev.c:7168 [inline]
net_rx_action+0x4d4/0xa10 net/core/dev.c:7258
handle_softirqs+0x339/0x830 kernel/softirq.c:576
run_ksoftirqd+0xa4/0x100 kernel/softirq.c:943
smpboot_thread_fn+0x4f6/0x970 kernel/smpboot.c:164
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287