INFO: task syz.3.1818:12765 blocked for more than 144 seconds. Not tainted 6.12.0-rc6-syzkaller-00225-g50643bbc9eb6 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1818 state:D stack:25056 pid:12765 tgid:12738 ppid:5825 flags:0x00024004 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x17fa/0x4bd0 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6782 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2591 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x355/0x620 kernel/sched/completion.c:148 io_wq_exit_workers io_uring/io-wq.c:1249 [inline] io_wq_put_and_exit+0x344/0x720 io_uring/io-wq.c:1277 io_uring_clean_tctx+0x168/0x1e0 io_uring/tctx.c:193 io_uring_cancel_generic+0x76a/0x820 io_uring/io_uring.c:3219 io_uring_files_cancel include/linux/io_uring.h:20 [inline] do_exit+0x6a8/0x28e0 kernel/exit.c:895 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 get_signal+0x16a3/0x1740 kernel/signal.c:2917 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f28e197e719 RSP: 002b:00007f28e26ca0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f28e1b36060 RCX: 00007f28e197e719 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f28e1b36060 RBP: 00007f28e1b36058 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f28e1b36064 R13: 0000000000000000 R14: 00007ffd8d6c5e10 R15: 00007ffd8d6c5ef8 Showing all locks held in the system: 5 locks held by kworker/0:0/8: #0: ffff888020af8148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff888020af8148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900000d7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900000d7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffff8880288b0190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #2: ffff8880288b0190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1fe/0x5150 drivers/usb/core/hub.c:5849 #3: ffff88804d4eb190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff88804d4eb190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8e/0x520 drivers/base/dd.c:1005 #4: ffff888027a11b68 (hcd->bandwidth_mutex){+.+.}-{3:3}, at: usb_set_configuration+0x4fb/0x1fb0 drivers/usb/core/message.c:2077 1 lock held by khungtaskd/30: #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 2 locks held by getty/5582: #0: ffff888034b320a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900032532f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 2 locks held by kworker/u8:18/8395: 1 lock held by iou-wrk-12765/12766: #0: ffff888011ffe0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_ring_submit_lock io_uring/io_uring.h:249 [inline] #0: ffff888011ffe0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_provide_buffers+0xd0b/0x1010 io_uring/kbuf.c:580 1 lock held by iou-wrk-12765/12767: #0: ffff888011ffe0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_ring_submit_lock io_uring/io_uring.h:249 [inline] #0: ffff888011ffe0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_provide_buffers+0xd0b/0x1010 io_uring/kbuf.c:580 1 lock held by iou-wrk-12765/12768: #0: ffff888011ffe0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_ring_submit_lock io_uring/io_uring.h:249 [inline] #0: ffff888011ffe0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_provide_buffers+0xd0b/0x1010 io_uring/kbuf.c:580 3 locks held by iou-wrk-12765/12769: 1 lock held by iou-wrk-12765/12770: #0: ffff888011ffe0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_ring_submit_lock io_uring/io_uring.h:249 [inline] #0: ffff888011ffe0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_provide_buffers+0xd0b/0x1010 io_uring/kbuf.c:580 1 lock held by iou-wrk-12765/12771: #0: ffff888011ffe0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_ring_submit_lock io_uring/io_uring.h:249 [inline] #0: ffff888011ffe0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_provide_buffers+0xd0b/0x1010 io_uring/kbuf.c:580 1 lock held by iou-wrk-12765/12772: #0: ffff888011ffe0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_ring_submit_lock io_uring/io_uring.h:249 [inline] #0: ffff888011ffe0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_provide_buffers+0xd0b/0x1010 io_uring/kbuf.c:580 1 lock held by iou-wrk-12765/12773: #0: ffff888011ffe0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_ring_submit_lock io_uring/io_uring.h:249 [inline] #0: ffff888011ffe0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_provide_buffers+0xd0b/0x1010 io_uring/kbuf.c:580 2 locks held by syz.9.2224/14230: #0: ffff888079b94a08 (&sb->s_type->i_mutex_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline] #0: ffff888079b94a08 (&sb->s_type->i_mutex_key#9){+.+.}-{3:3}, at: __sock_release net/socket.c:657 [inline] #0: ffff888079b94a08 (&sb->s_type->i_mutex_key#9){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1426 #1: ffffffff8e93d338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #1: ffffffff8e93d338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc6-syzkaller-00225-g50643bbc9eb6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 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+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/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 CPU: 1 UID: 0 PID: 47 Comm: kworker/1:1 Not tainted 6.12.0-rc6-syzkaller-00225-g50643bbc9eb6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Workqueue: events dvb_usb_read_remote_control RIP: 0010:io_serial_in+0x76/0xb0 drivers/tty/serial/8250/8250_port.c:406 Code: 20 74 52 fc 89 e9 41 d3 e6 48 83 c3 40 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 71 16 b9 fc 44 03 33 44 89 f2 ec <0f> b6 c0 5b 41 5e 41 5f 5d c3 cc cc cc cc 89 e9 80 e1 07 38 c1 7c RSP: 0018:ffffc90000b774d8 EFLAGS: 00000002 RAX: 1ffffffff34dc900 RBX: ffffffff9a6e4c80 RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: 0000000000000000 R08: ffffffff854265d6 R09: 1ffff1100498d046 R10: dffffc0000000000 R11: ffffffff85426590 R12: dffffc0000000000 R13: ffffffff9a3dfef0 R14: 00000000000003fd R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f63eef08ab8 CR3: 000000000e734000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_in drivers/tty/serial/8250/8250.h:137 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline] wait_for_lsr drivers/tty/serial/8250/8250_port.c:2068 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3315 [inline] serial8250_console_write+0x1373/0x1ed0 drivers/tty/serial/8250/8250_port.c:3393 console_emit_next_record kernel/printk/printk.c:3092 [inline] console_flush_all+0x869/0xeb0 kernel/printk/printk.c:3180 __console_flush_and_unlock kernel/printk/printk.c:3239 [inline] console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3279 vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2407 _printk+0xd5/0x120 kernel/printk/printk.c:2432 dvb_usb_read_remote_control+0x143/0x1b0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:263 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244