INFO: task syz-executor481:5033 blocked for more than 143 seconds. Not tainted 6.6.0-rc6-syzkaller-00029-g213f891525c2 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor481 state:D stack:27392 pid:5033 ppid:5032 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0xee1/0x5a10 kernel/sched/core.c:6695 schedule+0xe7/0x1b0 kernel/sched/core.c:6771 schedule_timeout+0x278/0x2c0 kernel/time/timer.c:2143 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common+0x3e0/0x5f0 kernel/sched/completion.c:116 __flush_workqueue+0x3e0/0x1320 kernel/workqueue.c:3195 nbd_start_device_ioctl drivers/block/nbd.c:1426 [inline] __nbd_ioctl drivers/block/nbd.c:1487 [inline] nbd_ioctl+0x308/0xd60 drivers/block/nbd.c:1527 blkdev_ioctl+0x2f9/0x770 block/ioctl.c:630 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl fs/ioctl.c:857 [inline] __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f9ee9c96879 RSP: 002b:00007fff48042fb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9ee9c96879 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f9ee9d095f0 R08: 0000000000000006 R09: 0000000000000006 R10: 0000000000000006 R11: 0000000000000246 R12: 0000000000000001 R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001 Showing all locks held in the system: 2 locks held by kworker/u4:1/12: 1 lock held by khungtaskd/29: #0: ffffffff8cbab2e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:303 [inline] #0: ffffffff8cbab2e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:749 [inline] #0: ffffffff8cbab2e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6613 2 locks held by kworker/u5:1/4439: #0: ffff88801c699138 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x787/0x15c0 kernel/workqueue.c:2605 #1: ffffc9000ddc7d80 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x7e9/0x15c0 kernel/workqueue.c:2606 2 locks held by getty/4784: #0: ffff888025b0e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc5/0x1480 drivers/tty/n_tty.c:2206 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.6.0-rc6-syzkaller-00029-g213f891525c2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x277/0x380 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x299/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf87/0x1210 kernel/hung_task.c:379 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 12 Comm: kworker/u4:1 Not tainted 6.6.0-rc6-syzkaller-00029-g213f891525c2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:insn_field_set arch/x86/include/asm/insn.h:29 [inline] RIP: 0010:insn_get_modrm+0x1ab/0x730 arch/x86/lib/insn.c:350 Code: 6d 00 4c 89 7b 68 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 <0f> 85 18 04 00 00 48 8d 7b 25 44 89 6b 20 48 b8 00 00 00 00 00 fc RSP: 0018:ffffc90000117918 EFLAGS: 00000246 RAX: 0000000000000003 RBX: ffffc90000117a68 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8a354643 RDI: ffffc90000117a88 RBP: ffffc90000117a8c R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000000 R12: ffffc90000117ab4 R13: 0000000000000044 R14: 0000000000004000 R15: ffffffff8a867c2d FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000562a86698348 CR3: 000000000c976000 CR4: 0000000000350ee0 Call Trace: insn_get_sib+0x1ad/0x320 arch/x86/lib/insn.c:421 insn_get_displacement+0x23a/0x680 arch/x86/lib/insn.c:464 insn_get_immediate+0x550/0x1c50 arch/x86/lib/insn.c:632 insn_get_length arch/x86/lib/insn.c:707 [inline] insn_decode+0x2ae/0x340 arch/x86/lib/insn.c:747 text_poke_loc_init+0xdf/0x5d0 arch/x86/kernel/alternative.c:2320 arch_jump_label_transform_queue+0xaf/0x110 arch/x86/kernel/jump_label.c:138 __jump_label_update+0x125/0x420 kernel/jump_label.c:475 jump_label_update+0x32e/0x410 kernel/jump_label.c:829 static_key_disable_cpuslocked+0x154/0x1b0 kernel/jump_label.c:235 static_key_disable+0x1a/0x20 kernel/jump_label.c:243 toggle_allocation_gate mm/kfence/core.c:835 [inline] toggle_allocation_gate+0x13f/0x250 mm/kfence/core.c:822 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304