INFO: task syz-executor:2558 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:2558 tgid:2558 ppid:1 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:6016 [inline] __schedule+0x1399/0x1fa0 kernel/sched/core.c:7870 __schedule_loop kernel/sched/core.c:7951 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7966 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8023 __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:10887 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+0x1e8/0x260 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: 0033:0x7fa3c1b9c819 RSP: 002b:00007ffdd24ea958 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fa3c1c320ba RCX: 00007fa3c1b9c819 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000016 R08: 0000000000000000 R09: 00007fa3c1c32048 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdd24ebc10 R13: 00007fa3c1c32048 R14: 0000555562ec34e8 R15: 00007ffdd24eddd0 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 a07f00d2ee7d03658d1c696b901c19adfab1cc4a Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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+0x2c6/0x370 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: 2822 Comm: syz-executor Not tainted syzkaller #0 a07f00d2ee7d03658d1c696b901c19adfab1cc4a Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:task_stack_page include/linux/sched/task_stack.h:23 [inline] RIP: 0010:last_frame arch/x86/kernel/unwind_frame.c:82 [inline] RIP: 0010:is_last_frame arch/x86/kernel/unwind_frame.c:87 [inline] RIP: 0010:is_last_task_frame arch/x86/kernel/unwind_frame.c:156 [inline] RIP: 0010:unwind_next_frame+0x10d/0x750 arch/x86/kernel/unwind_frame.c:276 Code: f7 e8 c7 27 9b 00 48 ba 00 00 00 00 00 fc ff df 4c 89 75 98 49 8b 06 48 89 45 a8 4c 8d 68 20 4c 89 e8 48 c1 e8 03 80 3c 10 00 <74> 12 4c 89 ef e8 99 27 9b 00 48 ba 00 00 00 00 00 fc ff df 49 8b RSP: 0018:ffffc900011af3a8 EFLAGS: 00000246 RAX: 1ffff11023104984 RBX: ffffc900011af428 RCX: 00000000011af400 RDX: dffffc0000000000 RSI: ffffffff81eb284e RDI: ffffc900011af428 RBP: ffffc900011af418 R08: ffffc900011af4f0 R09: ffffc900011af4e8 R10: 0000000000000004 R11: ffffffff8175da00 R12: 0000000000000000 R13: ffff888118824c20 R14: ffffc900011af450 R15: ffffc900011af980 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbaf4545000 CR3: 0000000145cb6000 CR4: 00000000003526b0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x138/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 save_stack+0x125/0x240 mm/page_owner.c:174 __reset_page_owner+0x79/0x450 mm/page_owner.c:315 reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1390 [inline] free_unref_page+0xbcf/0xf80 mm/page_alloc.c:2876 __free_pages+0x6b/0x3b0 mm/page_alloc.c:5385 vfree+0x3ea/0x5b0 mm/vmalloc.c:3400 kcov_put kernel/kcov.c:439 [inline] kcov_close+0x2c/0x70 kernel/kcov.c:535 __fput+0x1fe/0xa00 fs/file_table.c:429 ____fput+0x20/0x30 fs/file_table.c:457 task_work_run+0x1e8/0x260 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: 0033:0x7f549dd57997 Code: Unable to access opcode bytes at 0x7f549dd5796d. RSP: 002b:00007ffd60625de0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: 0000000000000030 RBX: 000055557eafa500 RCX: 00007f549dd57997 RDX: 0000000000000030 RSI: 00007f549eb44670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffd60625e44 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f549eb44670 R15: 0000000000000000 net_ratelimit: 74387 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 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) 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:0e:fb:06:ce:7e:7c, 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 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)