INFO: task syz.3.5042:26466 blocked for more than 143 seconds. Not tainted 6.11.0-rc6-syzkaller-g9c0c11bb87b0 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.5042 state:D stack:28992 pid:26466 tgid:26456 ppid:19505 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: 0033:0x7fe73c41cef9 RSP: 002b:00007fe73b055038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fe73c5d6130 RCX: 00007fe73c41cef9 RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000004 RBP: 00007fe73c48f046 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fe73c5d6130 R15: 00007fff9e733288 Showing all locks held in the system: 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 5 locks held by kworker/1:2/42: #0: ffff888105e82148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1277/0x1b40 kernel/workqueue.c:3206 #1: ffffc900004d7d80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1b40 kernel/workqueue.c:3207 #2: ffff888109b3e190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #2: ffff888109b3e190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 #3: ffff88811cee4190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #3: ffff88811cee4190 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0x10a/0x920 drivers/usb/core/hub.c:2295 #4: ffff88812d3be160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #4: ffff88812d3be160 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1094 [inline] #4: ffff88812d3be160 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa4/0x610 drivers/base/dd.c:1292 2 locks held by getty/2604: #0: ffff888100ea60a0 (&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 syz.3.5042/26465: #0: ffff88811b40bcb0 (&dev->io_mutex){+.+.}-{3:3}, at: yurex_write+0x17f/0x930 drivers/usb/misc/yurex.c:448 1 lock held by syz.3.5042/26466: #0: ffff88811b40bcb0 (&dev->io_mutex){+.+.}-{3:3}, at: yurex_write+0x17f/0x930 drivers/usb/misc/yurex.c:448 1 lock held by syz.2.5517/28362: #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.4.5518/28369: #0: ffffffff88ec6df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:328 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc6-syzkaller-g9c0c11bb87b0 #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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 4929 Comm: kworker/0:4 Not tainted 6.11.0-rc6-syzkaller-g9c0c11bb87b0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Workqueue: events dvb_usb_read_remote_control RIP: 0010:check_wait_context kernel/locking/lockdep.c:4773 [inline] RIP: 0010:__lock_acquire+0x44e/0x3cb0 kernel/locking/lockdep.c:5092 Code: 00 00 48 89 f9 48 c1 e9 03 0f b6 14 11 48 89 f9 83 e1 07 38 ca 7f 08 84 d2 0f 85 49 2b 00 00 4c 89 ef 44 0f b6 a0 c4 00 00 00 1d 56 ff ff 48 ba 00 00 00 00 00 fc ff df 48 8d b8 c5 00 00 00 RSP: 0018:ffffc90000007c78 EFLAGS: 00000046 RAX: ffffffff8fa560b8 RBX: 0000000000000000 RCX: 0000000000000004 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888101748ae8 RBP: 0000000000000001 R08: 0000000000000000 R09: fffffbfff1f4a3dd R10: ffffffff8fa51eef R11: 0000000000000000 R12: 0000000000000002 R13: ffff888101748ae8 R14: 000000000000004f R15: ffff888101748000 FS: 0000000000000000(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7532321000 CR3: 0000000111da6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5759 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:170 __run_timer_base kernel/time/timer.c:2427 [inline] __run_timer_base kernel/time/timer.c:2421 [inline] run_timer_base+0x109/0x190 kernel/time/timer.c:2437 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2447 handle_softirqs+0x209/0x8e0 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:637 [inline] irq_exit_rcu+0xac/0x110 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2010 [inline] RIP: 0010:vprintk_emit+0x396/0x600 kernel/printk/printk.c:2347 Code: 00 4d 85 e4 0f 85 04 02 00 00 e8 a5 ce 1e 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 03 d1 1e 00 48 85 ed 0f 85 10 02 00 00 85 ce 1e 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00 RSP: 0018:ffffc9000240fb78 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 000000000000003e RCX: ffffffff8135c706 RDX: ffff888101748000 RSI: ffffffff8135c710 RDI: 0000000000000007 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000200 R13: ffff888101e8d7c0 R14: ffffffff87c48620 R15: ffffc9000240fbf8 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:45 _printk+0xc8/0x100 kernel/printk/printk.c:2373 dvb_usb_read_remote_control+0x174/0x1c0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:263 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389 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