INFO: task syz-executor:294 blocked for more than 122 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:294 tgid:294 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:6026 [inline] __schedule+0x1399/0x1fa0 kernel/sched/core.c:7880 __schedule_loop kernel/sched/core.c:7961 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7976 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8033 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285 rcu_barrier+0x4d/0x540 kernel/rcu/tree.c:4589 netdev_run_todo+0x118/0xce0 net/core/dev.c:10900 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:3520 __fput+0x1fe/0xa00 fs/file_table.c:429 ____fput+0x20/0x30 fs/file_table.c:457 task_work_run+0x1e5/0x260 kernel/task_work.c:246 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x9ad/0x2720 kernel/exit.c:954 do_group_exit+0x229/0x2f0 kernel/exit.c:1096 get_signal+0x1398/0x14e0 kernel/signal.c:2933 arch_do_signal_or_restart+0xbc/0x760 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+0x57/0xb0 kernel/entry/common.c:218 do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fb659957f57 RSP: 002b:00007fff54881930 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: 0000000000000005 RBX: 000055557af17500 RCX: 00007fb659957f57 RDX: 0000000000000000 RSI: 00007fff54881a80 RDI: ffffffffffffff9c RBP: 00007fff54881a80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff54882b10 R13: 00007fb659a32120 R14: 000055557af174e8 R15: 0000000000000005 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 f1e96da778e106ed2ad9fef94b5d954a2cba2451 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120 dump_stack+0x19/0x20 lib/dump_stack.c:129 nmi_cpu_backtrace+0x2ba/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+0xdad/0xf00 kernel/hung_task.c:423 kthread+0x2c9/0x370 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 286 Comm: syz-executor Not tainted syzkaller #0 f1e96da778e106ed2ad9fef94b5d954a2cba2451 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:get_current arch/x86/include/asm/current.h:49 [inline] RIP: 0010:update_stack_state+0x3ae/0x4b0 arch/x86/kernel/unwind_frame.c:252 Code: 00 00 00 00 48 83 45 d0 08 eb 0c 48 83 e8 80 48 89 45 d0 4c 8b 6d c0 48 8b 45 90 42 80 3c 20 00 74 08 4c 89 ef e8 02 5f 9b 00 <65> 48 8b 05 3a 1d c0 7e 49 39 45 00 74 0e 48 8b 7d d0 e8 1b fc ff RSP: 0018:ffffc90000006ff8 EFLAGS: 00000246 RAX: 1ffff92000000e2e RBX: ffffc90000007148 RCX: ffffc90000007501 RDX: ffffc90000007580 RSI: 1ffff92000000e2a RDI: ffffc900000071a0 RBP: ffffc900000070b8 R08: ffffc90000007210 R09: ffffc90000007208 R10: 0000000000000003 R11: ffffffff8175e9a0 R12: dffffc0000000000 R13: ffffc90000007170 R14: ffffc900000071a0 R15: 1ffff92000000e31 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa298147e20 CR3: 000000010c7d6000 CR4: 00000000003526b0 Call Trace: unwind_next_frame+0x3c1/0x750 arch/x86/kernel/unwind_frame.c:315 arch_stack_walk+0x138/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:49 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:70 kasan_save_alloc_info+0x40/0x50 mm/kasan/generic.c:565 unpoison_slab_object mm/kasan/common.c:321 [inline] __kasan_slab_alloc+0x73/0x90 mm/kasan/common.c:347 kasan_slab_alloc include/linux/kasan.h:251 [inline] slab_post_alloc_hook mm/slub.c:4202 [inline] slab_alloc_node mm/slub.c:4251 [inline] kmem_cache_alloc_node_noprof+0x1ca/0x420 mm/slub.c:4305 kmalloc_reserve+0xcf/0x4f0 net/core/skbuff.c:596 __alloc_skb+0x144/0x370 net/core/skbuff.c:687 alloc_skb include/linux/skbuff.h:1363 [inline] nlmsg_new include/net/netlink.h:1015 [inline] fdb_notify+0x78/0x150 net/bridge/br_fdb.c:195 br_fdb_update+0x4b7/0x680 net/bridge/br_fdb.c:945 br_handle_frame_finish+0x399/0x17a0 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+0xfae/0x3ab0 net/core/dev.c:5683 __netif_receive_skb_one_core net/core/dev.c:5787 [inline] __netif_receive_skb net/core/dev.c:5902 [inline] process_backlog+0x3e5/0xad0 net/core/dev.c:6238 __napi_poll+0xd0/0x610 net/core/dev.c:6889 napi_poll net/core/dev.c:6958 [inline] net_rx_action+0x5ea/0xd80 net/core/dev.c:7080 handle_softirqs+0x1aa/0x630 kernel/softirq.c:621 __do_softirq+0xf/0x16 kernel/softirq.c:659 do_softirq+0xb8/0x110 kernel/softirq.c:503 __local_bh_enable_ip+0x74/0x80 kernel/softirq.c:430 __raw_write_unlock_bh include/linux/rwlock_api_smp.h:281 [inline] _raw_write_unlock_bh+0x33/0x70 kernel/locking/spinlock.c:366 sock_orphan include/net/sock.h:2075 [inline] __tcp_close+0x698/0xd10 net/ipv4/tcp.c:3167 tcp_close+0x2d/0x120 net/ipv4/tcp.c:3250 inet_release+0x1b0/0x2b0 net/ipv4/af_inet.c:442 __sock_release net/socket.c:659 [inline] sock_close+0xda/0x280 net/socket.c:1426 __fput+0x1fe/0xa00 fs/file_table.c:429 ____fput+0x20/0x30 fs/file_table.c:457 task_work_run+0x1e5/0x260 kernel/task_work.c:246 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x9ad/0x2720 kernel/exit.c:954 do_group_exit+0x229/0x2f0 kernel/exit.c:1096 __do_sys_exit_group kernel/exit.c:1107 [inline] __se_sys_exit_group kernel/exit.c:1105 [inline] __x64_sys_exit_group+0x43/0x50 kernel/exit.c:1105 x64_sys_call+0x2ed2/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:47 [inline] do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fa29739cdd9 Code: Unable to access opcode bytes at 0x7fa29739cdaf. RSP: 002b:00007ffed10afde8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fa29744dd71 RCX: 00007fa29739cdd9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043 RBP: 00007fa29744dd8f R08: 0000000000000000 R09: 00007ffed10aff0c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009 R13: 00007ffed10aff0c R14: 00007ffed10affa0 R15: 0000000000000000 net_ratelimit: 107230 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:ee:18:9e:e7:7e:87, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:ee:18:9e:e7:7e:87, 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:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)