INFO: task kworker/u8:1:13 blocked for more than 123 seconds. Not tainted 6.12.38-syzkaller-gd0c633175c04 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:1 state:D stack:0 pid:13 tgid:13 ppid:2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: 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 cleanup_net+0x8f2/0xc70 net/core/net_namespace.c:653 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0x7d2/0x1020 kernel/workqueue.c:3319 worker_thread+0xc58/0x1250 kernel/workqueue.c:3400 kthread+0x2ca/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 INFO: task kworker/1:1:45 blocked for more than 124 seconds. Not tainted 6.12.38-syzkaller-gd0c633175c04 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:1 state:D stack:0 pid:45 tgid:45 ppid:2 flags:0x00004000 Workqueue: events fqdir_free_fn Call Trace: 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+0x7d2/0x1020 kernel/workqueue.c:3319 worker_thread+0xc58/0x1250 kernel/workqueue.c:3400 kthread+0x2ca/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 INFO: task syz-executor:5477 blocked for more than 124 seconds. Not tainted 6.12.38-syzkaller-gd0c633175c04 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:0 pid:5477 tgid:5477 ppid:1 flags:0x00004004 Call Trace: 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 default_device_exit_batch+0x815/0x8a0 net/core/dev.c:12035 ops_exit_list net/core/net_namespace.c:178 [inline] setup_net+0x6f3/0x990 net/core/net_namespace.c:388 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: 0033:0x7f5a7e3903e7 RSP: 002b:00007ffe5da1c4c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f5a7e5b5f40 RCX: 00007f5a7e3903e7 RDX: 0000000000000005 RSI: 00007ffe5da1c390 RDI: 0000000040000000 RBP: 00007f5a7e5b67b8 R08: 00007f5a7f0e7d60 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 INFO: task syz-executor:5478 blocked for more than 124 seconds. Not tainted 6.12.38-syzkaller-gd0c633175c04 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:0 pid:5478 tgid:5478 ppid:1 flags:0x00004004 Call Trace: 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 default_device_exit_batch+0x815/0x8a0 net/core/dev.c:12035 ops_exit_list net/core/net_namespace.c:178 [inline] setup_net+0x6f3/0x990 net/core/net_namespace.c:388 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: 0033:0x7f7b341903e7 RSP: 002b:00007fffad1414c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f7b343b5f40 RCX: 00007f7b341903e7 RDX: 0000000000000005 RSI: 00007fffad141390 RDI: 0000000040000000 RBP: 00007f7b343b67b8 R08: 00007f7b34ee7d60 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 INFO: task syz-executor:5479 blocked for more than 125 seconds. Not tainted 6.12.38-syzkaller-gd0c633175c04 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:0 pid:5479 tgid:5479 ppid:1 flags:0x00004006 Call Trace: 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+0x1fe/0xa00 fs/file_table.c:429 ____fput+0x20/0x30 fs/file_table.c:457 task_work_run+0x1e0/0x250 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: 0033:0x7f4c53b90a23 RSP: 002b:00007ffd3b442288 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: 0000000000000030 RBX: 00007f4c548e4620 RCX: 00007f4c53b90a23 RDX: 0000000000000030 RSI: 00007f4c548e4670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffd3b4422a4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f4c548e4670 R15: 0000000000000000 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted 6.12.38-syzkaller-gd0c633175c04 #0 79f03ae2e0a264f34f505a942aaa3597bcba712e Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __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+0x2ca/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 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 33 Comm: rcuop/1 Not tainted 6.12.38-syzkaller-gd0c633175c04 #0 79f03ae2e0a264f34f505a942aaa3597bcba712e Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:br_fdb_update+0x64/0x680 net/bridge/br_fdb.c:892 Code: 24 80 00 00 00 49 bf 00 00 00 00 00 fc ff df 48 c7 44 24 40 b3 8a b5 41 48 c7 44 24 48 1a f9 e6 86 48 c7 44 24 50 30 bb fe 84 <4c> 8d 6c 24 40 49 c1 ed 03 48 b8 f1 f1 f1 f1 00 f3 f3 f3 4b 89 44 RSP: 0018:ffffc90000230680 EFLAGS: 00000282 RAX: 0d9191c4c97afc00 RBX: ffff888100bd8ac0 RCX: 0000000000000000 RDX: ffff88811410e008 RSI: ffff8881314e6000 RDI: ffff888100bd8ac0 RBP: ffffc90000230750 R08: 0000000000000000 R09: 0000000000000000 R10: ffff88815ba72168 R11: ffffed102b74e42f R12: ffff88811410e008 R13: ffff8881314e6000 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000560c0ebe6b90 CR3: 000000010b3c6000 CR4: 00000000003526b0 DR0: 0000000000000000 DR1: 0000000000000097 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: br_handle_frame_finish+0x39c/0x1720 net/bridge/br_input.c:141 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+0xf4b/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 __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+0x2ca/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 net_ratelimit: 79879 callbacks suppressed bridge0: received packet on bridge_slave_0 with own address as source address (addr:10:20:10:00:00:00, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:10:20:10:00:00:00, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:10:20:10:00:00:00, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:10:20:10:00:00:00, 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:10:20:10:00:00:00, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:10:20:10:00:00:00, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:10:20:10:00:00:00, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:10:20:10:00:00:00, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:10:20:10:00:00:00, vlan:0)