INFO: task syz.5.1523:12685 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.1523 state:D stack:24536 pid:12685 tgid:12682 ppid:9650 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x1522/0x51d0 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0x164/0x360 kernel/sched/core.c:6964 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776 sync_bdevs+0x27e/0x470 block/bdev.c:1305 ksys_sync+0xc5/0x170 fs/sync.c:105 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6a6039aeb9 RSP: 002b:00007f6a6133b028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f6a60615fa0 RCX: 00007f6a6039aeb9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f6a60615fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6a60616038 R14: 00007f6a60615fa0 R15: 00007ffdde583e68 Showing all locks held in the system: 1 lock held by khungtaskd/32: #0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 5 locks held by kworker/u8:3/50: #0: ffff88801b2df148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88801b2df148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc90000bb7bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90000bb7bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8f99ddb0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xfe/0x7b0 net/core/net_namespace.c:670 #3: ffff8880330c14e8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_destruct+0x116/0x310 drivers/net/wireguard/device.c:249 #4: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #4: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:956 3 locks held by kworker/u8:6/3431: #0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc9000bc77bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000bc77bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8f9ac6c8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 2 locks held by getty/5576: #0: ffff8880307960a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 2 locks held by dhcpcd/10669: #0: ffff88805541ef48 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff88805541ef48 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline] #0: ffff88805541ef48 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455 #1: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #1: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:956 1 lock held by udevd/10964: #0: ffff8880254c0358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962 1 lock held by udevd/11254: #0: ffff8880256a7358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962 1 lock held by syz.5.1523/12685: #0: ffff8880256a7358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1305 3 locks held by syz-executor/12962: 2 locks held by syz-executor/14346: #0: ffffffff8f1112c8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8f1112c8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8f1112c8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f9ac6c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f9ac6c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f9ac6c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 2 locks held by syz.0.1870/14540: #0: ffff88807eb287c8 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff88807eb287c8 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline] #0: ffff88807eb287c8 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455 #1: ffff88802a5e4260 (sk_lock-AF_CAN){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1700 [inline] #1: ffff88802a5e4260 (sk_lock-AF_CAN){+.+.}-{0:0}, at: bcm_release+0x1cd/0x940 net/can/bcm.c:1601 6 locks held by dhcpcd-run-hook/14571: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 32 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 14346 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:debug_smp_processor_id+0x0/0x20 lib/smp_processor_id.c:57 Code: 00 7a 62 8e 4c 89 f6 e8 7e f5 45 f9 e9 67 ff ff ff cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 c7 c7 a0 3a 07 8c 48 c7 c6 e0 3a 07 8c eb 1c 66 66 RSP: 0018:ffffc9000b8e6508 EFLAGS: 00000002 RAX: 0000000000000003 RBX: 0000000000000993 RCX: ffffffff99fe3403 RDX: 00000000000001a7 RSI: ffffffff8c073ae0 RDI: 0000000000000001 RBP: 0000000000000000 R08: ffff8880248f8237 R09: 1ffff1100491f046 R10: dffffc0000000000 R11: ffffffff8b95c150 R12: 1ffffffff34670a6 R13: 00000000ffffffff R14: 000001a7c5427064 R15: 00000000000003d4 FS: 000055557fa89500(0000) GS:ffff8881256f3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb3fc292a90 CR3: 0000000037eea000 CR4: 0000000000350ef0 Call Trace: delay_tsc+0x6a/0xc0 arch/x86/lib/delay.c:90 udelay include/asm-generic/delay.h:62 [inline] wait_for_lsr+0x160/0x2f0 drivers/tty/serial/8250/8250_port.c:1967 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline] serial8250_console_write+0x1348/0x1ba0 drivers/tty/serial/8250/8250_port.c:3342 console_emit_next_record kernel/printk/printk.c:3129 [inline] console_flush_one_record kernel/printk/printk.c:3215 [inline] console_flush_all+0x718/0xb20 kernel/printk/printk.c:3289 __console_flush_and_unlock kernel/printk/printk.c:3319 [inline] console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3359 vprintk_emit+0x485/0x560 kernel/printk/printk.c:2426 _printk+0xdd/0x130 kernel/printk/printk.c:2451 netdev_info+0x11e/0x180 net/core/dev.c:12971 team_port_add drivers/net/team/team_core.c:1256 [inline] team_add_slave+0x225d/0x2970 drivers/net/team/team_core.c:1927 do_set_master+0x533/0x6d0 net/core/rtnetlink.c:2963 do_setlink+0x1018/0x4590 net/core/rtnetlink.c:3165 rtnl_changelink net/core/rtnetlink.c:3776 [inline] __rtnl_newlink net/core/rtnetlink.c:3935 [inline] rtnl_newlink+0x15a9/0x1be0 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] __sys_sendto+0x709/0x7a0 net/socket.c:2206 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2209 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc148f5b78e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007ffc0e631a68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000055557fa89500 RCX: 00007fc148f5b78e RDX: 0000000000000028 RSI: 00007fc149d44670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffc0e631ae4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 00007fc149d44670 R15: 0000000000000000