INFO: task syz-executor.3:11092 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.3 state:D stack:28496 pid:11092 ppid: 7700 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: 0033:0x7f545e268ae9 RSP: 002b:00007f545b7bd188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f545e37c020 RCX: 00007f545e268ae9 RDX: 0000000000000007 RSI: 000000000000ab00 RDI: 0000000000000006 RBP: 00007f545e2c2f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd4a1ff22f R14: 00007f545b7bd300 R15: 0000000000022000 INFO: task syz-executor.3:11106 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.3 state:D stack:29592 pid:11106 ppid: 7700 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: 0033:0x7f545e268ae9 RSP: 002b:00007f545b79c188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f545e37c0e0 RCX: 00007f545e268ae9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 00007f545e2c2f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd4a1ff22f R14: 00007f545b79c300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb83b60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by in:imklog/6206: #0: ffff88801b1d2d70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 1 lock held by syz-executor.3/11092: #0: ffff88801aeaa198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x151/0xb10 drivers/block/nbd.c:1504 1 lock held by syz-executor.3/11106: #0: ffff88801aeaa198 (&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:111 nmi_trigger_cpumask_backtrace+0x1b3/0x230 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: 6505 Comm: syz-fuzzer Not tainted 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_kcov_mode kernel/kcov.c:166 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x7/0x60 kernel/kcov.c:200 Code: 46 00 5d be 03 00 00 00 e9 56 13 63 02 66 0f 1f 44 00 00 48 8b be b0 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 8b 05 99 d6 8a 7e <89> c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 40 70 02 00 a9 RSP: 0018:ffffc90001a3fb48 EFLAGS: 00000202 RAX: 0000000080000001 RBX: ffffc90001a3fcc0 RCX: ffff888017a33a00 RDX: 0000000000000000 RSI: ffff888017a33a00 RDI: 0000000000000003 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff83fecac8 R11: 0000000000000000 R12: ffffc90001a3fcd8 R13: ffffc90000df2f48 R14: ffffc90001a3fce0 R15: 0000000000000000 FS: 000000c00002e090(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f861ab6a028 CR3: 000000001903c000 CR4: 0000000000350ee0 Call Trace: __list_del_entry include/linux/list.h:137 [inline] list_del_init include/linux/list.h:206 [inline] plist_del+0x1c6/0x480 lib/plist.c:130 __futex_unqueue+0xc9/0x1b0 kernel/futex/core.c:513 futex_unqueue+0x79/0x120 kernel/futex/core.c:610 futex_wait+0x2d1/0x670 kernel/futex/waitwake.c:660 do_futex+0x205/0x390 kernel/futex/syscalls.c:122 __do_sys_futex kernel/futex/syscalls.c:199 [inline] __se_sys_futex kernel/futex/syscalls.c:180 [inline] __x64_sys_futex+0x1b0/0x4a0 kernel/futex/syscalls.c:180 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: 0033:0x46e203 Code: 24 20 c3 cc cc cc cc 48 8b 7c 24 08 8b 74 24 10 8b 54 24 14 4c 8b 54 24 18 4c 8b 44 24 20 44 8b 4c 24 28 b8 ca 00 00 00 0f 05 <89> 44 24 30 c3 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc RSP: 002b:000000c00003de80 EFLAGS: 00000202 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 000000c00002e000 RCX: 000000000046e203 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 0000000001864c98 RBP: 000000c00003dec8 R08: 0000000000000000 R09: 0000000000000000 R10: 000000c00003deb8 R11: 0000000000000202 R12: 000000000043b6e0 R13: 0000000000000000 R14: 00000000008db92c R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 46 00 5d be rex.RX add %r11b,-0x42(%rbp) 4: 03 00 add (%rax),%eax 6: 00 00 add %al,(%rax) 8: e9 56 13 63 02 jmpq 0x2631363 d: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 13: 48 8b be b0 01 00 00 mov 0x1b0(%rsi),%rdi 1a: e8 b4 ff ff ff callq 0xffffffd3 1f: 31 c0 xor %eax,%eax 21: c3 retq 22: 90 nop 23: 65 8b 05 99 d6 8a 7e mov %gs:0x7e8ad699(%rip),%eax # 0x7e8ad6c3 * 2a: 89 c1 mov %eax,%ecx <-- trapping instruction 2c: 48 8b 34 24 mov (%rsp),%rsi 30: 81 e1 00 01 00 00 and $0x100,%ecx 36: 65 48 8b 14 25 40 70 mov %gs:0x27040,%rdx 3d: 02 00 3f: a9 .byte 0xa9