INFO: task kworker/1:4:747 blocked for more than 122 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:4     state:D stack:0     pid:747   tgid:747   ppid:2      flags:0x00004000
Workqueue: events fqdir_free_fn
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
 rcu_barrier+0x4d/0x530 kernel/rcu/tree.c:4589
 fqdir_free_fn+0x36/0x150 net/ipv4/inet_fragment.c:167
 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+0x64/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task syz.2.1374:4325 blocked for more than 124 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.1374      state:D stack:0     pid:4325  tgid:4325  ppid:2697   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
 rcu_barrier+0x4d/0x530 kernel/rcu/tree.c:4589
 netdev_run_todo+0x10e/0xcb0 net/core/dev.c:10868
 rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152
 tun_detach drivers/net/tun.c:704 [inline]
 tun_chr_close+0xc5/0x150 drivers/net/tun.c:3517
 __fput+0x1fb/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
 ret_from_fork+0x3a/0xa0 arch/x86/kernel/process.c:162
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
RIP: 0033:0x7f09cd38ebe9
RSP: 002b:00007f09cbdf6fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: 0000000000000000 RBX: 00007f09cd5c5fa0 RCX: 00007f09cd38ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f09cd411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f09cd5c6038 R14: 00007f09cd5c5fa0 R15: 00007ffceb2a9f38
 </TASK>
INFO: task syz.1.1988:6089 blocked for more than 124 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1988      state:D stack:0     pid:6089  tgid:6086  ppid:5546   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_timeout+0xb2/0x3a0 kernel/time/timer.c:2595
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common+0x359/0x630 kernel/sched/completion.c:127
 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148
 rcu_barrier+0x415/0x530 kernel/rcu/tree.c:4657
 netdev_run_todo+0x10e/0xcb0 net/core/dev.c:10868
 rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152
 tun_detach drivers/net/tun.c:704 [inline]
 tun_chr_close+0xc5/0x150 drivers/net/tun.c:3517
 __fput+0x1fb/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: 0033:0x7f7bf0f8ebe9
RSP: 002b:00007f7bf1ec3038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007f7bf11c6090 RCX: 00007f7bf0f8ebe9
RDX: 0000200000002280 RSI: 0000000000008914 RDI: 0000000000000008
RBP: 00007f7bf1011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7bf11c6128 R14: 00007f7bf11c6090 R15: 00007ffe5a559658
 </TASK>
INFO: task syz.3.1985:6090 blocked for more than 124 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1985      state:D stack:0     pid:6090  tgid:6088  ppid:294    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
 rcu_barrier+0x4d/0x530 kernel/rcu/tree.c:4589
 setup_net+0x8cf/0x990 net/core/net_namespace.c:394
 copy_net_ns+0x513/0xa30 net/core/net_namespace.c:510
 create_new_namespaces+0x3b5/0x720 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x126/0x180 kernel/nsproxy.c:228
 ksys_unshare+0x4fe/0x880 kernel/fork.c:3352
 __do_sys_unshare kernel/fork.c:3423 [inline]
 __se_sys_unshare kernel/fork.c:3421 [inline]
 __x64_sys_unshare+0x3c/0x50 kernel/fork.c:3421
 x64_sys_call+0x2998/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:273
 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: 0033:0x7f5eb518ebe9
RSP: 002b:00007f5eb5fe9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f5eb53c5fa0 RCX: 00007f5eb518ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000064000600
RBP: 00007f5eb5211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5eb53c6038 R14: 00007f5eb53c5fa0 R15: 00007ffff455ffd8
 </TASK>
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 73b2ef142dafea13a051d13948dec704a9c677a1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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+0x64/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 33 Comm: rcuop/1 Not tainted syzkaller #0 73b2ef142dafea13a051d13948dec704a9c677a1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:stack_trace_save+0x74/0xe0 kernel/stacktrace.c:119
Code: 48 b9 f1 f1 f1 f1 00 00 00 f3 49 be 00 00 00 00 00 fc ff df 4a 89 0c 33 42 c7 44 33 08 f3 f3 f3 f3 48 89 7c 24 20 89 74 24 28 <ff> c2 89 54 24 2c 48 c7 44 24 30 00 00 00 00 65 48 8b 14 25 40 eb
RSP: 0018:ffffc90000006ce0 EFLAGS: 00000a06
RAX: ffffc90000006d00 RBX: 1ffff92000000d9c RCX: f3000000f1f1f1f1
RDX: 0000000000000002 RSI: 0000000000000010 RDI: ffffc90000006dc0
RBP: ffffc90000006d70 R08: ffffc90000006e3f R09: 0000000000000000
R10: ffffc90000006dc0 R11: fffff52000000dc8 R12: dffffc0000000000
R13: 1ffff92000000db4 R14: dffffc0000000000 R15: 1ffff110206cf580
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7d9c8f7d60 CR3: 00000000072a8000 CR4: 00000000003526b0
Call Trace:
 <IRQ>
 save_stack+0xf8/0x1f0 mm/page_owner.c:174
 __set_page_owner+0x8e/0x5d0 mm/page_owner.c:338
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook+0x3b9/0x3f0 mm/page_alloc.c:1826
 prep_new_page+0x1c/0x120 mm/page_alloc.c:1834
 get_page_from_freelist+0x48ce/0x4960 mm/page_alloc.c:3914
 __alloc_pages_noprof+0x31f/0x7b0 mm/page_alloc.c:5258
 alloc_slab_page+0x6b/0x1f0 mm/slub.c:-1
 allocate_slab+0x69/0x440 mm/slub.c:2660
 new_slab mm/slub.c:2714 [inline]
 ___slab_alloc+0x59a/0x8b0 mm/slub.c:3902
 __slab_alloc mm/slub.c:3992 [inline]
 __slab_alloc_node mm/slub.c:4045 [inline]
 slab_alloc_node mm/slub.c:4206 [inline]
 kmem_cache_alloc_noprof+0x202/0x3a0 mm/slub.c:4227
 skb_clone+0x229/0x460 net/core/skbuff.c:2082
 deliver_clone net/bridge/br_forward.c:125 [inline]
 br_flood+0x661/0x730 net/bridge/br_forward.c:245
 br_handle_frame_finish+0x12bb/0x1720 net/bridge/br_input.c:215
 nf_hook_bridge_pre net/bridge/br_input.c:301 [inline]
 br_handle_frame+0x5a6/0xba0 net/bridge/br_input.c:424
 __netif_receive_skb_core+0xf48/0x3940 net/core/dev.c:5651
 __netif_receive_skb_one_core net/core/dev.c:5755 [inline]
 __netif_receive_skb net/core/dev.c:5870 [inline]
 process_backlog+0x3e5/0xae0 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+0x64/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
net_ratelimit: 73132 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:00:00:00:00:79:74, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:e6:43:84:22:1b:e8, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:00:00:00:00:79:74, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:e6:43:84:22:1b:e8, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:00:00:00:00:79:74, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:00:00:00:00:79:74, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:00:00:00:00:79:74, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:e6:43:84:22:1b:e8, vlan:0)
net_ratelimit: 102884 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:00:00:00:00:79:74, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:00:00:00:00:79:74, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:00:00:00:00:79:74, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:00:00:00:00:79:74, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:00:00:00:00:79:74, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:00:00:00:00:79:74, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:00:00:00:00:79:74, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)