INFO: task syz.5.2707:16813 blocked for more than 143 seconds. Not tainted 6.15.0-rc5-syzkaller-00038-g707df3375124 #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.2707 state:D stack:24904 pid:16813 tgid:16810 ppid:7307 task_flags:0x400548 flags:0x00024000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 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+0x2bf/0x5d0 kernel/sched/completion.c:148 io_wq_exit_workers io_uring/io-wq.c:1294 [inline] io_wq_put_and_exit+0x31b/0x690 io_uring/io-wq.c:1322 io_uring_clean_tctx+0x11f/0x1a0 io_uring/tctx.c:205 io_uring_cancel_generic+0x68f/0x730 io_uring/io_uring.c:3216 io_uring_files_cancel include/linux/io_uring.h:19 [inline] do_exit+0x56a/0x2550 kernel/exit.c:909 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 get_signal+0x125e/0x1310 kernel/signal.c:3034 arch_do_signal_or_restart+0x95/0x780 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:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x8b/0x120 kernel/entry/common.c:218 do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7a6044d980 RSP: 002b:00007f7a6144bb38 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007f7a607b5fa8 RCX: 00007f7a6058e969 RDX: 00007f7a6144bb40 RSI: 00007f7a6144bc70 RDI: 0000000000000011 RBP: 00007f7a607b5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7a607b5fac R13: 0000000000000000 R14: 00007f7a608df940 R15: 00007f7a608dfa28 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 2 locks held by getty/5593: #0: ffff8880343ca0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036cb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 6 locks held by kworker/1:6/5892: #0: ffff8880206cdd48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff8880206cdd48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc9000434fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000434fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffff8881457f0198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #2: ffff8881457f0198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a00 drivers/usb/core/hub.c:5859 #3: ffff8881457f3510 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3220 [inline] #3: ffff8881457f3510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5428 [inline] #3: ffff8881457f3510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5671 [inline] #3: ffff8881457f3510 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5831 [inline] #3: ffff8881457f3510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x21a3/0x4a00 drivers/usb/core/hub.c:5913 #4: ffff8881453b5b68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5429 [inline] #4: ffff8881453b5b68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5671 [inline] #4: ffff8881453b5b68 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5831 [inline] #4: ffff8881453b5b68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x21cb/0x4a00 drivers/usb/core/hub.c:5913 #5: ffff8880b8839b58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:613 2 locks held by kworker/0:6/5912: #0: ffff8880b8839b58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:613 #1: ffff8880b8823b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x318/0x6d0 kernel/sched/psi.c:975 1 lock held by iou-wrk-16813/16821: #0: ffff88808aec20a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:289 [inline] #0: ffff88808aec20a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_provide_buffers+0x7a1/0xa70 io_uring/kbuf.c:562 1 lock held by iou-wrk-16813/16823: #0: ffff88808aec20a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:289 [inline] #0: ffff88808aec20a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_provide_buffers+0x7a1/0xa70 io_uring/kbuf.c:562 2 locks held by iou-wrk-16813/16824: 1 lock held by iou-wrk-16813/16825: #0: ffff88808aec20a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:289 [inline] #0: ffff88808aec20a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_provide_buffers+0x7a1/0xa70 io_uring/kbuf.c:562 1 lock held by iou-wrk-16813/16826: #0: ffff88808aec20a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:289 [inline] #0: ffff88808aec20a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_provide_buffers+0x7a1/0xa70 io_uring/kbuf.c:562 2 locks held by syz.1.3167/19021: #0: ffffffff8f2f47c8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff8f2f47c8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3390 #1: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #1: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc5-syzkaller-00038-g707df3375124 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:437 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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 6.15.0-rc5-syzkaller-00038-g707df3375124 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81 Code: cc cc cc cc cc cc cc 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 03 eb 11 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6 RAX: c72c5763ba85de00 RBX: ffffffff81974f28 RCX: c72c5763ba85de00 RDX: 0000000000000001 RSI: ffffffff8d74aa4f RDI: ffffffff8bc1d1e0 RBP: ffffc90000197f20 R08: ffff8880b8932b5b R09: 1ffff1101712656b R10: dffffc0000000000 R11: ffffed101712656c R12: ffffffff8f7ed970 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110038d9b40 FS: 0000000000000000(0000) GS:ffff8881261cb000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f095d9aecf8 CR3: 000000004b812000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 3a810b1eb6134bdc DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:748 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147