INFO: task syz-executor266:5033 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-executor266 state:D stack:26096 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: 0033:0x7f116382e879 RSP: 002b:00007fffa70fb5c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f116382e879 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f11638a15f0 R08: 0000000000000006 R09: 0000000000000006 R10: 0000000000000006 R11: 0000000000000246 R12: 0000000000000001 R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001 Showing all locks held in the system: 1 lock held by khungtaskd/28: #0: ffffffff8cba7960 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:303 [inline] #0: ffffffff8cba7960 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:749 [inline] #0: ffffffff8cba7960 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6613 2 locks held by kworker/u4:5/942: #0: ffff888012c77938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x787/0x15c0 kernel/workqueue.c:2605 #1: ffffc90004e07d80 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work+0x7e9/0x15c0 kernel/workqueue.c:2606 2 locks held by kworker/u5:1/4435: #0: ffff888141372d38 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x787/0x15c0 kernel/workqueue.c:2605 #1: ffffc90002fcfd80 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x7e9/0x15c0 kernel/workqueue.c:2606 2 locks held by getty/4789: #0: ffff88814be0c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900020682f0 (&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: 28 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: 942 Comm: kworker/u4:5 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:__sanitizer_cov_trace_pc+0x3b/0x70 kernel/kcov.c:207 Code: 81 e1 00 01 00 00 65 48 8b 14 25 00 bd 03 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 04 16 00 00 85 c0 74 2b 8b 82 e0 15 00 00 <83> f8 02 75 20 48 8b 8a e8 15 00 00 8b 92 e4 15 00 00 48 8b 01 48 RSP: 0018:ffffc90004e07960 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff888012c68558 RCX: 0000000000000000 RDX: ffff88801e14a180 RSI: ffffffff81c766bd RDI: 0000000000000006 RBP: 0000000012c68007 R08: 0000000000000006 R09: 0000000012c68067 R10: 0000000012c68067 R11: 0000000000000000 R12: ffff888012c62040 R13: 00002aaaaaaab000 R14: ffffc90004e07a10 R15: 8000000000000063 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f09a3fc56c0 CR3: 000000000c976000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pte_offset_map_lock include/linux/mm.h:2940 [inline] __get_locked_pte+0x7d/0xc0 mm/memory.c:1822 get_locked_pte include/linux/mm.h:2664 [inline] __text_poke+0x224/0xc90 arch/x86/kernel/alternative.c:1820 text_poke arch/x86/kernel/alternative.c:1905 [inline] text_poke_bp_batch+0x62e/0x960 arch/x86/kernel/alternative.c:2294 text_poke_flush arch/x86/kernel/alternative.c:2407 [inline] text_poke_flush arch/x86/kernel/alternative.c:2404 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2414 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 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 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.259 msecs