INFO: task syz-executor.4:27344 blocked for more than 143 seconds. Not tainted 5.16.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:28496 pid:27344 ppid: 25789 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6253 schedule+0xd2/0x260 kernel/sched/core.c:6326 blk_mq_freeze_queue_wait+0x112/0x160 block/blk-mq.c:178 nbd_add_socket+0x166/0x810 drivers/block/nbd.c:1109 __nbd_ioctl drivers/block/nbd.c:1454 [inline] nbd_ioctl+0x38c/0xb10 drivers/block/nbd.c:1511 blkdev_ioctl+0x37a/0x800 block/ioctl.c:609 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f9866d33ae9 RSP: 002b:00007f9864288188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f9866e47020 RCX: 00007f9866d33ae9 RDX: 0000000000000007 RSI: 000000000000ab00 RDI: 0000000000000006 RBP: 00007f9866d8df6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffee04bc9ff R14: 00007f9864288300 R15: 0000000000022000 INFO: task syz-executor.4:27352 blocked for more than 143 seconds. Not tainted 5.16.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:29592 pid:27352 ppid: 25789 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6253 schedule+0xd2/0x260 kernel/sched/core.c:6326 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6385 __mutex_lock_common kernel/locking/mutex.c:680 [inline] __mutex_lock+0xa32/0x12f0 kernel/locking/mutex.c:740 nbd_ioctl+0x151/0xb10 drivers/block/nbd.c:1504 blkdev_ioctl+0x37a/0x800 block/ioctl.c:609 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f9866d33ae9 RSP: 002b:00007f9864267188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f9866e470e0 RCX: 00007f9866d33ae9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 00007f9866d8df6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffee04bc9ff R14: 00007f9864267300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb83a60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by in:imklog/6217: #0: ffff88801d5805f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 2 locks held by rs:main Q:Reg/6218: #0: ffff8880759579f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 #1: ffff88807f3a4460 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x12d/0x250 fs/read_write.c:643 1 lock held by syz-executor.4/27344: #0: ffff88801a98d998 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x151/0xb10 drivers/block/nbd.c:1504 1 lock held by syz-executor.4/27352: #0: ffff88801a98d998 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x151/0xb10 drivers/block/nbd.c:1504 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xc1d/0xf50 kernel/hung_task.c:295 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2963 Comm: systemd-journal Not tainted 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:127 [inline] RIP: 0010:check_preemption_disabled+0x4d/0x170 lib/smp_processor_id.c:19 Code: e3 ff ff ff 7f 31 ff 89 de 0f 1f 44 00 00 85 db 74 11 0f 1f 44 00 00 44 89 e0 5b 5d 41 5c 41 5d 41 5e c3 0f 1f 44 00 00 9c 5b <81> e3 00 02 00 00 31 ff 48 89 de 0f 1f 44 00 00 48 85 db 74 d3 0f RSP: 0018:ffffc9000206fee0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000046 RCX: 0000000000000000 RDX: ffff88807ae80000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff8a051620 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff817e26bd R11: 0000000000000000 R12: 0000000000000001 R13: ffffffff8a0515e0 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fbd044578c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbd01dce000 CR3: 000000007af86000 CR4: 0000000000350ee0 Call Trace: tick_nohz_user_enter_prepare include/linux/tick.h:310 [inline] exit_to_user_mode_prepare+0x31/0x290 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fbd037129c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd8a144d38 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: 0000000000000000 RBX: 00007ffd8a147c50 RCX: 00007fbd037129c7 RDX: 00007fbd04183a00 RSI: 0000000000000000 RDI: 0000564200a539a3 RBP: 00007ffd8a144d70 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffd8a147c50 R15: 00007ffd8a145260 ---------------- Code disassembly (best guess), 4 bytes skipped: 0: 7f 31 jg 0x33 2: ff 89 de 0f 1f 44 decl 0x441f0fde(%rcx) 8: 00 00 add %al,(%rax) a: 85 db test %ebx,%ebx c: 74 11 je 0x1f e: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 13: 44 89 e0 mov %r12d,%eax 16: 5b pop %rbx 17: 5d pop %rbp 18: 41 5c pop %r12 1a: 41 5d pop %r13 1c: 41 5e pop %r14 1e: c3 retq 1f: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 24: 9c pushfq 25: 5b pop %rbx * 26: 81 e3 00 02 00 00 and $0x200,%ebx <-- trapping instruction 2c: 31 ff xor %edi,%edi 2e: 48 89 de mov %rbx,%rsi 31: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 36: 48 85 db test %rbx,%rbx 39: 74 d3 je 0xe 3b: 0f .byte 0xf