INFO: task kworker/u8:4:2185 blocked for more than 123 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:4    state:D stack:0     pid:2185  tgid:2185  ppid:2      flags:0x00004000
Workqueue: events_unbound linkwatch_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5945 [inline]
 __schedule+0x1322/0x1df0 kernel/sched/core.c:7791
 __schedule_loop kernel/sched/core.c:7872 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7887
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285
 rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79
 linkwatch_event+0x12/0x60 net/core/link_watch.c:285
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x7d5/0x1020 kernel/workqueue.c:3319
 worker_thread+0xc58/0x1250 kernel/workqueue.c:3400
 kthread+0x2c7/0x370 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task syz-executor:2189 blocked for more than 125 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:2189  tgid:2189  ppid:1      flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5945 [inline]
 __schedule+0x1322/0x1df0 kernel/sched/core.c:7791
 __schedule_loop kernel/sched/core.c:7872 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7887
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285
 rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79
 tun_detach drivers/net/tun.c:698 [inline]
 tun_chr_close+0x41/0x150 drivers/net/tun.c:3517
 __fput+0x1fe/0xa00 fs/file_table.c:429
 ____fput+0x20/0x30 fs/file_table.c:457
 task_work_run+0x1e3/0x250 kernel/task_work.c:240
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0x9bc/0x2630 kernel/exit.c:953
 do_group_exit+0x22a/0x300 kernel/exit.c:1095
 get_signal+0x139d/0x14f0 kernel/signal.c:2933
 arch_do_signal_or_restart+0x96/0x720 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x58/0xb0 kernel/entry/common.c:218
 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f9388790a63
RSP: 002b:00007fffb25a0a88 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: 0000000000000038 RBX: 00007f9389504620 RCX: 00007f9388790a63
RDX: 0000000000000038 RSI: 00007f9389504670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007fffb25a0aa4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f9389504670 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:2191 blocked for more than 127 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:2191  tgid:2191  ppid:1      flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5945 [inline]
 __schedule+0x1322/0x1df0 kernel/sched/core.c:7791
 __schedule_loop kernel/sched/core.c:7872 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7887
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285
 rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79
 tun_detach drivers/net/tun.c:698 [inline]
 tun_chr_close+0x41/0x150 drivers/net/tun.c:3517
 __fput+0x1fe/0xa00 fs/file_table.c:429
 ____fput+0x20/0x30 fs/file_table.c:457
 task_work_run+0x1e3/0x250 kernel/task_work.c:240
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0x9bc/0x2630 kernel/exit.c:953
 do_group_exit+0x22a/0x300 kernel/exit.c:1095
 get_signal+0x139d/0x14f0 kernel/signal.c:2933
 arch_do_signal_or_restart+0x96/0x720 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x58/0xb0 kernel/entry/common.c:218
 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f3ca5b90a63
RSP: 002b:00007ffe4e0a58e8 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: 0000000000000028 RBX: 00007f3ca6904620 RCX: 00007f3ca5b90a63
RDX: 0000000000000028 RSI: 00007f3ca6904670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffe4e0a5904 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f3ca6904670 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:2202 blocked for more than 128 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:2202  tgid:2202  ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5945 [inline]
 __schedule+0x1322/0x1df0 kernel/sched/core.c:7791
 __schedule_loop kernel/sched/core.c:7872 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7887
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285
 rtnl_lock net/core/rtnetlink.c:79 [inline]
 rtnetlink_rcv_msg+0x75f/0xa00 net/core/rtnetlink.c:6675
 netlink_rcv_skb+0x22b/0x4a0 net/netlink/af_netlink.c:2555
 rtnetlink_rcv+0x20/0x30 net/core/rtnetlink.c:6696
 netlink_unicast_kernel net/netlink/af_netlink.c:1323 [inline]
 netlink_unicast+0x8c3/0xa60 net/netlink/af_netlink.c:1349
 netlink_sendmsg+0x7f0/0xaf0 net/netlink/af_netlink.c:1899
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x66a/0x6f0 net/socket.c:2217
 __do_sys_sendto net/socket.c:2229 [inline]
 __se_sys_sendto net/socket.c:2225 [inline]
 __x64_sys_sendto+0xe9/0x100 net/socket.c:2225
 x64_sys_call+0x2c2c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:45
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f293f990a63
RSP: 002b:00007ffd4b9f3508 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f2940704620 RCX: 00007f293f990a63
RDX: 000000000000002c RSI: 00007f2940704670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffd4b9f3524 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f2940704670 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:2204 blocked for more than 130 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:2204  tgid:2204  ppid:1      flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5945 [inline]
 __schedule+0x1322/0x1df0 kernel/sched/core.c:7791
 __schedule_loop kernel/sched/core.c:7872 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7887
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285
 rtnl_lock net/core/rtnetlink.c:79 [inline]
 rtnetlink_rcv_msg+0x75f/0xa00 net/core/rtnetlink.c:6675
 netlink_rcv_skb+0x22b/0x4a0 net/netlink/af_netlink.c:2555
 rtnetlink_rcv+0x20/0x30 net/core/rtnetlink.c:6696
 netlink_unicast_kernel net/netlink/af_netlink.c:1323 [inline]
 netlink_unicast+0x8c3/0xa60 net/netlink/af_netlink.c:1349
 netlink_sendmsg+0x7f0/0xaf0 net/netlink/af_netlink.c:1899
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x66a/0x6f0 net/socket.c:2217
 __do_sys_sendto net/socket.c:2229 [inline]
 __se_sys_sendto net/socket.c:2225 [inline]
 __x64_sys_sendto+0xe9/0x100 net/socket.c:2225
 x64_sys_call+0x2c2c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:45
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7effcb590a63
RSP: 002b:00007fff42b87768 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007effcc304620 RCX: 00007effcb590a63
RDX: 000000000000002c RSI: 00007effcc304670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007fff42b87784 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000000000000 R14: 00007effcc304670 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:2206 blocked for more than 131 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:2206  tgid:2206  ppid:1      flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5945 [inline]
 __schedule+0x1322/0x1df0 kernel/sched/core.c:7791
 __schedule_loop kernel/sched/core.c:7872 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7887
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285
 rtnl_lock net/core/rtnetlink.c:79 [inline]
 rtnetlink_rcv_msg+0x75f/0xa00 net/core/rtnetlink.c:6675
 netlink_rcv_skb+0x22b/0x4a0 net/netlink/af_netlink.c:2555
 rtnetlink_rcv+0x20/0x30 net/core/rtnetlink.c:6696
 netlink_unicast_kernel net/netlink/af_netlink.c:1323 [inline]
 netlink_unicast+0x8c3/0xa60 net/netlink/af_netlink.c:1349
 netlink_sendmsg+0x7f0/0xaf0 net/netlink/af_netlink.c:1899
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x66a/0x6f0 net/socket.c:2217
 __do_sys_sendto net/socket.c:2229 [inline]
 __se_sys_sendto net/socket.c:2225 [inline]
 __x64_sys_sendto+0xe9/0x100 net/socket.c:2225
 x64_sys_call+0x2c2c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:45
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7ffa15990a63
RSP: 002b:00007fff5aa18228 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007ffa16704620 RCX: 00007ffa15990a63
RDX: 000000000000002c RSI: 00007ffa16704670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007fff5aa18244 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000000000000 R14: 00007ffa16704670 R15: 0000000000000000
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 26040f0ed9382bf65720d717d6d6db2d10869199
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:94
 dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120
 dump_stack+0x19/0x20 lib/dump_stack.c:129
 nmi_cpu_backtrace+0x2bf/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline]
 watchdog+0xd8f/0xed0 kernel/hung_task.c:423
 kthread+0x2c7/0x370 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 20 Comm: rcuop/0 Not tainted syzkaller #0 26040f0ed9382bf65720d717d6d6db2d10869199
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:55 [inline]
RIP: 0010:update_stack_state+0x17a/0x4b0 arch/x86/kernel/unwind_frame.c:228
Code: ff ff ff eb 1e 48 8b 73 28 4c 89 ff 48 89 da 48 8b 8d 60 ff ff ff e8 b5 ba f5 ff 85 c0 0f 85 2f 01 00 00 48 8b 85 40 ff ff ff <42> 80 3c 28 00 74 08 4c 89 f7 e8 17 09 98 00 4d 8b 3e 48 8b 85 48
RSP: 0018:ffffc90000230498 EFLAGS: 00000a02
RAX: 1ffff920000460be RBX: ffffc900002305e8 RCX: 1ffff920000460bf
RDX: 1ffff920000460c0 RSI: 1ffff920000460be RDI: ffffc90000230640
RBP: ffffc90000230558 R08: ffffc900002306b0 R09: ffffc900002306a8
R10: 000000000000000b R11: ffffffff817441e0 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffc900002305f0 R15: ffffc90000230fd8
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b402ce0b98 CR3: 0000000120d88000 CR4: 00000000003526b0
Call Trace:
 <IRQ>
 unwind_next_frame+0x3c2/0x750 arch/x86/kernel/unwind_frame.c:315
 arch_stack_walk+0x139/0x170 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9d/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:69
 kasan_save_free_info+0x4a/0x60 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:248 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:265
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2418 [inline]
 slab_free mm/slub.c:4672 [inline]
 kmem_cache_free+0x1c1/0x510 mm/slub.c:4779
 kfree_skbmem net/core/skbuff.c:-1 [inline]
 __kfree_skb+0x18f/0x210 net/core/skbuff.c:1203
 sk_skb_reason_drop+0xd8/0x310 net/core/skbuff.c:1240
 kfree_skb_reason include/linux/skbuff.h:1271 [inline]
 ip_rcv_finish_core+0xc13/0x1440 net/ipv4/ip_input.c:424
 ip_rcv_finish net/ipv4/ip_input.c:447 [inline]
 NF_HOOK include/linux/netfilter.h:317 [inline]
 ip_rcv+0xe4/0x2d0 net/ipv4/ip_input.c:569
 __netif_receive_skb_one_core net/core/dev.c:5757 [inline]
 __netif_receive_skb net/core/dev.c:5870 [inline]
 process_backlog+0x507/0xae0 net/core/dev.c:6206
 __napi_poll+0xd3/0x610 net/core/dev.c:6857
 napi_poll net/core/dev.c:6926 [inline]
 net_rx_action+0x584/0xce0 net/core/dev.c:7048
 handle_softirqs+0x1ab/0x630 kernel/softirq.c:621
 __do_softirq+0xf/0x16 kernel/softirq.c:659
 do_softirq+0xa6/0x100 kernel/softirq.c:503
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x74/0x80 kernel/softirq.c:430
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_do_batch+0x5c6/0xd20 kernel/rcu/tree.c:2594
 nocb_cb_wait kernel/rcu/tree_nocb.h:923 [inline]
 rcu_nocb_cb_kthread+0x4dc/0xac0 kernel/rcu/tree_nocb.h:957
 kthread+0x2c7/0x370 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>