INFO: task syz-executor:10349 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21064 pid:10349 tgid:10349 ppid:1 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 __bch2_fs_stop+0x704/0x900 fs/bcachefs/super.c:696 generic_shutdown_super+0x135/0x2c0 fs/super.c:643 bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2618 deactivate_locked_super+0xb9/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1375 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2214f501f7 RSP: 002b:00007ffce1489878 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f2214f501f7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffce1489930 RBP: 00007ffce1489930 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffce148a9c0 R13: 00007f2214fd1d7d R14: 0000000000107e0e R15: 00007ffce148aa00 Showing all locks held in the system: 4 locks held by kworker/u8:0/12: #0: ffff88801a6f4138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801a6f4138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90000117bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90000117bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecc6a20 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:658 #3: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890 net/core/dev.c:12719 4 locks held by pr/legacy/17: 1 lock held by khungtaskd/38: #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by udevd/5203: 1 lock held by dhcpcd/5499: #0: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_deladdr+0x20f/0x330 net/ipv6/addrconf.c:4799 2 locks held by getty/5596: #0: ffff88823bf280a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e7b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222 3 locks held by kworker/0:6/6009: #0: ffff888019898538 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019898538 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc900051afbc0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc900051afbc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 2 locks held by kworker/u8:12/7868: 3 locks held by kworker/u8:13/8676: #0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90003be7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90003be7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 1 lock held by syz-executor/10349: #0: ffff888062d360d0 (&type->s_umount_key#76){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888062d360d0 (&type->s_umount_key#76){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888062d360d0 (&type->s_umount_key#76){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 4 locks held by udevd/11187: 2 locks held by syz-executor/14693: #0: ffffffff8e43b9e0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e43b9e0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e43b9e0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056 1 lock held by syz-executor/14893: #0: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056 3 locks held by syz.6.970/14982: 2 locks held by syz.8.971/14984: 1 lock held by udevadm/15000: 4 locks held by syz.7.972/15002: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:rdtsc_ordered arch/x86/include/asm/tsc.h:57 [inline] RIP: 0010:delay_tsc+0x71/0xc0 arch/x86/lib/delay.c:72 Code: 00 00 e8 82 e0 99 f6 65 8b 05 ab 51 00 07 85 c0 74 1c f3 90 bf 01 00 00 00 e8 bb de 99 f6 e8 46 3c 01 00 39 c5 75 0e 0f 01 f9 <66> 90 eb bd e8 66 88 3d f6 eb dd 4c 29 fb e8 2c 3c 01 00 89 c5 0f RSP: 0018:ffffc90000167890 EFLAGS: 00000246 RAX: 00000000ea4bd95a RBX: 0000000000000899 RCX: 0000000000000001 RDX: 0000000000000275 RSI: ffffffff8b621660 RDI: ffffffff8b621620 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff8af5ee30 R12: 1ffffffff3275d12 R13: 00000000ffffffff R14: 00000275ea4bd050 R15: 0000000000000884 FS: 0000000000000000(0000) GS:ffff8881269bc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007efe06875000 CR3: 000000005bff6000 CR4: 00000000003526f0 Call Trace: udelay include/asm-generic/delay.h:62 [inline] wait_for_lsr+0x166/0x2f0 drivers/tty/serial/8250/8250_port.c:1990 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3288 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3311 [inline] serial8250_console_write+0x11bd/0x1b40 drivers/tty/serial/8250/8250_port.c:3396 console_emit_next_record kernel/printk/printk.c:3118 [inline] console_flush_all+0x695/0xcd0 kernel/printk/printk.c:3226 __console_flush_and_unlock+0xa4/0x240 kernel/printk/printk.c:3285 legacy_kthread_func+0x13b/0x1a0 kernel/printk/printk.c:3638 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245