INFO: task syz-executor237:5077 blocked for more than 143 seconds. Not tainted 6.9.0-rc7-syzkaller-00136-gf4345f05c0df #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor237 state:D stack:26008 pid:5077 tgid:5077 ppid:5076 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x1796/0x4a00 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2558 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 __flush_workqueue+0x7d6/0x1710 kernel/workqueue.c:4007 nbd_start_device_ioctl drivers/block/nbd.c:1463 [inline] __nbd_ioctl drivers/block/nbd.c:1524 [inline] nbd_ioctl+0xbd1/0xf40 drivers/block/nbd.c:1564 blkdev_ioctl+0x5e5/0x740 block/ioctl.c:642 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f910dff3879 RSP: 002b:00007ffd11b66aa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f910dff3879 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f910e0665f0 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/29: #0: ffffffff8e334da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8e334da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8e334da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 2 locks held by kworker/u9:1/4469: #0: ffff88802029d148 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3242 [inline] #0: ffff88802029d148 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3348 #1: ffffc9000d90fd00 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3243 [inline] #1: ffffc9000d90fd00 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3348 1 lock held by klogd/4514: #0: ffff8880b943e658 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 2 locks held by getty/4830: #0: ffff88802ed810a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f0e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.9.0-rc7-syzkaller-00136-gf4345f05c0df #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 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:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xfde/0x1020 kernel/hung_task.c:380 kthread+0x2f0/0x390 kernel/kthread.c:388 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 950 Comm: kworker/u8:6 Not tainted 6.9.0-rc7-syzkaller-00136-gf4345f05c0df #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:insn_get_prefixes+0x249/0x18b0 arch/x86/lib/insn.c:134 Code: 0d ef 21 f6 e9 72 01 00 00 e8 03 ef 21 f6 eb 1e e8 fc ee 21 f6 eb 13 e8 f5 ee 21 f6 eb 0c e8 ee ee 21 f6 eb 05 e8 e7 ee 21 f6 <4c> 8b 3c 24 48 b8 00 00 00 00 00 fc ff df 0f b6 04 03 84 c0 0f 85 RSP: 0018:ffffc900041175c0 EFLAGS: 00000293 RAX: ffffffff8b741894 RBX: 1ffffffff178ac11 RCX: ffff888020d99e00 RDX: 0000000000000000 RSI: 000000000000001f RDI: 000000000000000b RBP: 000000000000001f R08: ffffffff8b7417ac R09: 0000000000000000 R10: ffffc90004117920 R11: fffff52000822f2f R12: ffffffff8bc5608c R13: ffffffff8bc5608a R14: ffffffff8bc56099 R15: ffffc90004117920 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a398083600 CR3: 000000000e134000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: insn_get_opcode+0x65/0xa90 arch/x86/lib/insn.c:271 insn_get_modrm+0x63/0x730 arch/x86/lib/insn.c:340 insn_get_sib arch/x86/lib/insn.c:414 [inline] insn_get_displacement+0x151/0x9a0 arch/x86/lib/insn.c:455 insn_get_immediate+0x62/0x11f0 arch/x86/lib/insn.c:621 insn_get_length arch/x86/lib/insn.c:694 [inline] insn_decode+0x2d6/0x4c0 arch/x86/lib/insn.c:733 text_poke_loc_init+0xed/0x870 arch/x86/kernel/alternative.c:2400 arch_jump_label_transform_queue+0x8f/0x100 arch/x86/kernel/jump_label.c:138 __jump_label_update+0x177/0x3a0 kernel/jump_label.c:475 static_key_disable_cpuslocked+0xce/0x1c0 kernel/jump_label.c:235 static_key_disable+0x1a/0x20 kernel/jump_label.c:243 toggle_allocation_gate+0x1b8/0x250 mm/kfence/core.c:831 process_one_work kernel/workqueue.c:3267 [inline] process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3348 worker_thread+0x86d/0xd70 kernel/workqueue.c:3429 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.471 msecs