INFO: task syz.0.706:8691 blocked for more than 143 seconds. Not tainted 6.16.0-rc5-syzkaller-00266-g3f31a806a62e #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.706 state:D stack:27800 pid:8691 tgid:8689 ppid:5829 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6879 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:747 bdev_open+0x41a/0xe40 block/bdev.c:945 blkdev_open+0x280/0x3f0 block/fops.c:676 do_dentry_open+0x741/0x1c10 fs/open.c:964 vfs_open+0x82/0x3f0 fs/open.c:1094 do_open fs/namei.c:3896 [inline] path_openat+0x1de4/0x2cb0 fs/namei.c:4055 do_filp_open+0x20b/0x470 fs/namei.c:4082 do_sys_openat2+0x11b/0x1d0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f397478d290 RSP: 002b:00007f39755ceb70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000200 RCX: 00007f397478d290 RDX: 0000000000000200 RSI: 00007f39755cec10 RDI: 00000000ffffff9c RBP: 00007f39755cec10 R08: 0000000000000000 R09: 002364626e2f7665 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 0000000000000001 R14: 00007f39749b6080 R15: 00007fff536b1938 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e5c4dc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c4dc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c4dc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 2 locks held by getty/5600: #0: ffff888037e820a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 6 locks held by kworker/1:4/5909: #0: ffff8880222d4d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000475fd10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88802a4a8198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #2: ffff88802a4a8198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fa0 drivers/usb/core/hub.c:5894 #3: ffff888074c60198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #3: ffff888074c60198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004 #4: ffff888025bd1160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #4: ffff888025bd1160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004 #5: ffffffff8e478b70 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xa9/0x250 kernel/umh.c:214 5 locks held by kworker/0:6/5910: 1 lock held by udevd/6998: #0: ffff88814273a358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 1 lock held by syz.0.706/8691: #0: ffff88814273a358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 2 locks held by syz.2.1177/10726: #0: ffffffff8fb82f88 (input_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:225 [inline] #0: ffffffff8fb82f88 (input_mutex){+.+.}-{4:4}, at: __input_unregister_device+0x156/0x470 drivers/input/input.c:2221 #1: ffffffff8e5d03b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:336 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc5-syzkaller-00266-g3f31a806a62e #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:470 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 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: 0 Comm: swapper/1 Not tainted 6.16.0-rc5-syzkaller-00266-g3f31a806a62e #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: cb 6b 02 e9 83 fb 02 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d e3 b8 21 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197df8 EFLAGS: 000002c6 RAX: 00000000018df4ab RBX: 0000000000000001 RCX: ffffffff8b885c99 RDX: 0000000000000000 RSI: ffffffff8de32e47 RDI: ffffffff8c158f60 RBP: ffffed1003c5c488 R08: 0000000000000001 R09: ffffed10170a6645 R10: ffff8880b853322b R11: 0000000000000001 R12: 0000000000000001 R13: ffff88801e2e2440 R14: ffffffff90a98650 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124813000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbceb782178 CR3: 0000000074c97000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:749 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148