INFO: task syz-executor:289 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:289 tgid:289 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5996 [inline] __schedule+0x134f/0x1ea0 kernel/sched/core.c:7843 __schedule_loop kernel/sched/core.c:7924 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7939 schedule_timeout+0xc7/0x3b0 kernel/time/timer.c:2596 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common+0x369/0x650 kernel/sched/completion.c:127 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148 rcu_barrier+0x415/0x540 kernel/rcu/tree.c:4657 netdev_run_todo+0x118/0xce0 net/core/dev.c:10874 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+0x9e3/0x2650 kernel/exit.c:953 do_group_exit+0x229/0x2f0 kernel/exit.c:1095 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: 0033:0x7f36e899c71a RSP: 002b:00007fffe4b17d48 EFLAGS: 00000206 ORIG_RAX: 0000000000000036 RAX: 0000000000000000 RBX: 00007fffe4b17dd0 RCX: 00007f36e899c71a RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000003 RBP: 0000000000000003 R08: 00000000000002e8 R09: 0000000000000000 R10: 00007f36e8be1140 R11: 0000000000000206 R12: 00007f36e8be10e0 R13: 00007fffe4b17d6c R14: 0000000000000000 R15: 00007f36e8be1e60 INFO: task syz-executor:5770 blocked for more than 124 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:5770 tgid:5770 ppid:291 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5996 [inline] __schedule+0x134f/0x1ea0 kernel/sched/core.c:7843 __schedule_loop kernel/sched/core.c:7924 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7939 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7996 __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:10874 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+0x9e3/0x2650 kernel/exit.c:953 do_group_exit+0x229/0x2f0 kernel/exit.c:1095 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] irqentry_exit_to_user_mode+0x4d/0xb0 kernel/entry/common.c:231 irqentry_exit+0x16/0x60 kernel/entry/common.c:334 exc_page_fault+0x65/0xc0 arch/x86/mm/fault.c:1542 asm_exc_page_fault+0x2b/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7fa9e6b2a180 RSP: 002b:00007fff514831c8 EFLAGS: 00010286 RAX: ffffffffffffffff RBX: 00007fff514831d0 RCX: 0000000000000000 RDX: ffffffffffffffff RSI: 00007fff514831d0 RDI: 00000000000000c8 RBP: 00007fff5148360c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000296 R13: 0000000000000062 R14: 0000000000025f8d R15: 00007fff51483660 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 001c7e68fa735976e9f6b7ad125989e1d2b10b0e Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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: 36 Comm: kauditd Not tainted syzkaller #0 001c7e68fa735976e9f6b7ad125989e1d2b10b0e Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:io_serial_in+0x7b/0xc0 drivers/tty/serial/8250/8250_port.c:406 Code: e8 ea a0 64 fe 44 89 f9 d3 e3 49 83 c6 08 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 8b 67 bc fe 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f 5d e9 c5 13 7e 02 cc 44 89 f9 80 e1 RSP: 0018:ffffc9000025f690 EFLAGS: 00000002 RAX: 1ffffffff1182200 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffc9000025f6b0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8322fbd0 R12: dffffc0000000000 R13: 000000000000270d R14: ffffffff88c11508 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055797e763af8 CR3: 000000010bfc6000 CR4: 00000000003526b0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:137 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline] wait_for_lsr drivers/tty/serial/8250/8250_port.c:2069 [inline] fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3314 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3336 [inline] serial8250_console_write+0x14e6/0x21a0 drivers/tty/serial/8250/8250_port.c:3421 univ8250_console_write+0x6f/0xb0 drivers/tty/serial/8250/8250_core.c:396 console_emit_next_record kernel/printk/printk.c:3151 [inline] console_flush_all+0x5fa/0xac0 kernel/printk/printk.c:3239 __console_flush_and_unlock kernel/printk/printk.c:3298 [inline] console_unlock+0xf8/0x2c0 kernel/printk/printk.c:3338 vprintk_emit+0x282/0x650 kernel/printk/printk.c:2462 vprintk_default+0x2a/0x40 kernel/printk/printk.c:2477 vprintk+0x93/0xa0 kernel/printk/printk_safe.c:75 _printk+0xde/0x140 kernel/printk/printk.c:2487 kauditd_printk_skb kernel/audit.c:546 [inline] kauditd_hold_skb+0x1cc/0x230 kernel/audit.c:581 kauditd_send_queue+0x2c4/0x310 kernel/audit.c:766 kauditd_thread+0x4e0/0x740 kernel/audit.c:890 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 net_ratelimit: 116391 callbacks suppressed 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 veth0_to_bridge with own address as source address (addr:42:01:dc:32:c9:b2, 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:42:01:dc:32:c9:b2, 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:1b, 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: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) net_ratelimit: 133937 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 veth0_to_bridge with own address as source address (addr:42:01:dc:32:c9:b2, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:42:01:dc:32:c9:b2, 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:1b, 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: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 veth0_to_bridge with own address as source address (addr:42:01:dc:32:c9:b2, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)