INFO: task syz-executor.3:24189 blocked for more than 143 seconds. Not tainted 5.15.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.3 state:D stack:27328 pid:24189 ppid: 13930 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4969 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6250 schedule+0xd2/0x260 kernel/sched/core.c:6323 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: 0033:0x7f44a951aae9 RSP: 002b:00007f44a6a4e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f44a962e0e0 RCX: 00007f44a951aae9 RDX: 0000000000000006 RSI: 000000000000ab00 RDI: 0000000000000005 RBP: 00007f44a9574f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd2749e5af R14: 00007f44a6a4e300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb80fe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by systemd-journal/2970: #0: ffff8880b9d39b18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2b/0x120 kernel/sched/core.c:478 1 lock held by in:imklog/6229: #0: ffff888076fbab70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 1 lock held by syz-executor.3/24189: #0: ffff8881473fc198 (&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 5.15.0-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: 2970 Comm: systemd-journal Not tainted 5.15.0-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: 45 00 5d be 03 00 00 00 e9 26 b2 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 89 4f 8b 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:ffffc90001ac7a10 EFLAGS: 00000046 RAX: 0000000080000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff888018d0c000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff817d64e8 R11: 0000000000000000 R12: 0000000000000dc0 R13: 0000000000000dc0 R14: 0000000000000200 R15: ffff888023c72d40 FS: 00007febaacf78c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007feba83c3000 CR3: 00000000766ae000 CR4: 00000000003526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_hardirqs_on+0x6e/0x1c0 kernel/trace/trace_preemptirq.c:44 slab_alloc mm/slab.c:3317 [inline] kmem_cache_alloc+0x3bd/0x560 mm/slab.c:3507 kmem_cache_zalloc include/linux/slab.h:714 [inline] __alloc_file+0x21/0x280 fs/file_table.c:101 alloc_empty_file+0x6d/0x170 fs/file_table.c:150 path_openat+0xe1/0x2750 fs/namei.c:3545 do_filp_open+0x1aa/0x400 fs/namei.c:3586 do_sys_openat2+0x16d/0x4d0 fs/open.c:1212 do_sys_open fs/open.c:1228 [inline] __do_sys_open fs/open.c:1236 [inline] __se_sys_open fs/open.c:1232 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1232 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: 0033:0x7febaa286840 Code: 73 01 c3 48 8b 0d 68 77 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 89 bb 20 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e f6 ff ff 48 89 04 24 RSP: 002b:00007fffb24810a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007fffb24813b0 RCX: 00007febaa286840 RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 000055fe21580a70 RBP: 000000000000000d R08: 0000000000000000 R09: 00000000ffffffff R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff R13: 000055fe21575060 R14: 00007fffb2481370 R15: 000055fe215822d0 ---------------- Code disassembly (best guess): 0: 45 00 5d be add %r11b,-0x42(%r13) 4: 03 00 add (%rax),%eax 6: 00 00 add %al,(%rax) 8: e9 26 b2 63 02 jmpq 0x263b233 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 89 4f 8b 7e mov %gs:0x7e8b4f89(%rip),%eax # 0x7e8b4fb3 * 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