INFO: task syz.2.1537:10298 blocked for more than 143 seconds. Not tainted 6.11.0-rc7-syzkaller-00112-gf299cd11f753 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.1537 state:D stack:28992 pid:10298 tgid:10277 ppid:2656 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xcda/0x2f80 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6621 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752 yurex_write+0x17f/0x930 drivers/usb/misc/yurex.c:448 vfs_write+0x29a/0x1140 fs/read_write.c:588 ksys_write+0x12f/0x260 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5f5048def9 RSP: 002b:00007f5f4f0c5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f5f50646130 RCX: 00007f5f5048def9 RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000004 RBP: 00007f5f505009f6 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f5f50646130 R15: 00007ffcf45afc28 Showing all locks held in the system: 3 locks held by kworker/1:0/24: #0: ffff8881066ec548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1277/0x1b40 kernel/workqueue.c:3206 #1: ffffc9000019fd80 ((work_completion)(&hub->events)){+.+.}-{0:0} , at: process_one_work+0x921/0x1b40 kernel/workqueue.c:3207 #2: ffff8881097d3190 (&dev->mutex ){....}-{3:3} , at: device_lock include/linux/device.h:1009 [inline] , at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 1 lock held by khungtaskd/30: #0: ffffffff88ebb660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff88ebb660 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff88ebb660 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6626 3 locks held by kworker/0:2/806: 2 locks held by getty/2605: #0: ffff88810f7ec0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc8/0x1490 drivers/tty/n_tty.c:2211 1 lock held by udevd/4903: 4 locks held by udevd/4926: #0: ffff8881114f92f0 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xde/0x12c0 fs/seq_file.c:182 #1: ffff888113744088 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88813260b878 (kn->active#18){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff8881185df190 (&dev->mutex){....}-{3:3}, at: device_lock_interruptible include/linux/device.h:1014 [inline] #3: ffff8881185df190 (&dev->mutex){....}-{3:3}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 5 locks held by kworker/1:4/4938: #0: ffff8881066ec548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1277/0x1b40 kernel/workqueue.c:3206 #1: ffffc90004677d80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1b40 kernel/workqueue.c:3207 #2: ffff88810674a190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #2: ffff88810674a190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 #3: ffff88813239e190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #3: ffff88813239e190 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0x10a/0x920 drivers/usb/core/hub.c:2295 #4: ffff888120e99160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #4: ffff888120e99160 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1094 [inline] #4: ffff888120e99160 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa4/0x610 drivers/base/dd.c:1292 3 locks held by kworker/0:0/8826: 1 lock held by syz.2.1537/10297: #0: ffff888131251cb0 (&dev->io_mutex){+.+.}-{3:3}, at: yurex_write+0x17f/0x930 drivers/usb/misc/yurex.c:448 1 lock held by syz.2.1537/10298: #0: ffff888131251cb0 (&dev->io_mutex){+.+.}-{3:3}, at: yurex_write+0x17f/0x930 drivers/usb/misc/yurex.c:448 1 lock held by syz.0.1996/12051: #0: ffffffff88ec6df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:296 1 lock held by syz.1.1999/12063: #0: ffffffff88ec6df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:328 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc7-syzkaller-00112-gf299cd11f753 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119 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:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xf0c/0x1240 kernel/hung_task.c:379 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 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 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:111