INFO: task syz.4.1121:11704 blocked for more than 143 seconds. Not tainted 6.12.0-rc3-next-20241015-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1121 state:D stack:24672 pid:11704 tgid:11703 ppid:10908 flags:0x00024000 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x18af/0x4bd0 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6782 schedule_timeout+0xb0/0x290 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+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:3222 io_uring_files_cancel include/linux/io_uring.h:20 [inline] do_exit+0x6a8/0x28e0 kernel/exit.c:894 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 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: 0033:0x7efc6997dff9 RSP: 002b:00007efc6a8490e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007efc69b35f88 RCX: 00007efc6997dff9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007efc69b35f88 RBP: 00007efc69b35f80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007efc69b35f8c R13: 0000000000000000 R14: 00007ffc1c7fe490 R15: 00007ffc1c7fe578 Showing all locks held in the system: 3 locks held by kworker/u8:1/12: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90000117d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000117d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcdc488 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 1 lock held by khungtaskd/30: #0: ffffffff8e939e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e939e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e939e20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 3 locks held by kworker/u8:7/2470: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90009157d00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90009157d00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8e93f3b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #2: ffffffff8e93f3b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 7 locks held by kworker/u8:8/2926: 2 locks held by getty/4992: #0: ffff8880330fa0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031232f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 1 lock held by iou-wrk-11704/11707: #0: ffff888027efa0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_ring_submit_lock io_uring/io_uring.h:249 [inline] #0: ffff888027efa0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_provide_buffers+0xd0b/0x1010 io_uring/kbuf.c:580 1 lock held by iou-wrk-11704/11720: #0: ffff888027efa0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_ring_submit_lock io_uring/io_uring.h:249 [inline] #0: ffff888027efa0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_provide_buffers+0xd0b/0x1010 io_uring/kbuf.c:580 1 lock held by iou-wrk-11704/11722: 1 lock held by iou-wrk-11704/11723: #0: ffff888027efa0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_ring_submit_lock io_uring/io_uring.h:249 [inline] #0: ffff888027efa0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_provide_buffers+0xd0b/0x1010 io_uring/kbuf.c:580 1 lock held by iou-wrk-11704/11725: #0: ffff888027efa0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_ring_submit_lock io_uring/io_uring.h:249 [inline] #0: ffff888027efa0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_provide_buffers+0xd0b/0x1010 io_uring/kbuf.c:580 1 lock held by iou-wrk-11704/11727: 1 lock held by iou-wrk-11704/11728: #0: ffff888027efa0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_ring_submit_lock io_uring/io_uring.h:249 [inline] #0: ffff888027efa0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_provide_buffers+0xd0b/0x1010 io_uring/kbuf.c:580 2 locks held by udevd/11967: 1 lock held by syz.0.1196/12497: #0: ffffffff8fcdc488 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcdc488 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6746 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc3-next-20241015-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 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 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+0x21/0x30 drivers/acpi/processor_idle.c:111