INFO: task syz-executor.2:2564 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.2 state:D stack:26432 pid: 2564 ppid: 30380 flags:0x00004004 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 schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857 __down_common+0x2e0/0x420 kernel/locking/semaphore.c:224 down+0x70/0x90 kernel/locking/semaphore.c:62 console_lock+0x28/0x80 kernel/printk/printk.c:2524 con_shutdown+0x3d/0x90 drivers/tty/vt/vt.c:3431 release_tty+0xcb/0x610 drivers/tty/tty_io.c:1605 tty_init_dev.part.0+0x12a/0x610 drivers/tty/tty_io.c:1474 tty_init_dev include/linux/err.h:36 [inline] tty_open_by_driver drivers/tty/tty_io.c:2098 [inline] tty_open+0xb16/0x1000 drivers/tty/tty_io.c:2146 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4c8/0x1250 fs/open.c:822 do_open fs/namei.c:3426 [inline] path_openat+0x1cad/0x2750 fs/namei.c:3559 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_openat fs/open.c:1244 [inline] __se_sys_openat fs/open.c:1239 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1239 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: 0033:0x7fb85f92ca04 RSP: 002b:00007fb85cecdcc0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fb85fa8d020 RCX: 00007fb85f92ca04 RDX: 0000000000000002 RSI: 00007fb85cecdd60 RDI: 00000000ffffff9c RBP: 00007fb85cecdd60 R08: 0000000000000000 R09: 000000000000000e R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 00007fb85ffc0b2f R14: 00007fb85cece300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8b983a20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6461 1 lock held by in:imklog/6184: #0: ffff8880730bf770 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 1 lock held by vhost-25731/25732: 1 lock held by syz-executor.2/2564: #0: ffffffff8c393d68 (tty_mutex){+.+.}-{3:3}, at: tty_open_by_driver drivers/tty/tty_io.c:2062 [inline] #0: ffffffff8c393d68 (tty_mutex){+.+.}-{3:3}, at: tty_open+0x55e/0x1000 drivers/tty/tty_io.c:2146 5 locks held by syz-executor.2/2578: ============================================= 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: 25732 Comm: vhost-25731 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:197 Code: 01 f0 4d 89 03 e9 63 fd ff ff b9 ff ff ff ff ba 08 00 00 00 4d 8b 03 48 0f bd ca 49 8b 45 00 48 63 c9 e9 64 ff ff ff 0f 1f 00 <65> 8b 05 49 ab 8a 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b RSP: 0018:ffffc900057ffce8 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffc90015f70000 RDX: 1ffff1100751a8ef RSI: ffffffff86c7bd09 RDI: 0000000000000003 RBP: ffff88803a8d01a8 R08: 0000000000000000 R09: ffffffff8fd45b5f R10: ffffffff86c7bcfb R11: 0000000000000000 R12: ffff88803a8d4778 R13: 0000000000000000 R14: ffff88803a8d01a8 R15: ffff88803a8d01a8 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000002 CR3: 00000000793da000 CR4: 00000000003526e0 Call Trace: vhost_get_avail_idx drivers/vhost/vhost.c:1021 [inline] vhost_enable_notify+0x579/0xa00 drivers/vhost/vhost.c:2540 vhost_transport_do_send_pkt+0xd1d/0xfd0 drivers/vhost/vsock.c:122 vhost_worker+0x23d/0x3d0 drivers/vhost/vhost.c:372 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 01 f0 add %esi,%eax 2: 4d 89 03 mov %r8,(%r11) 5: e9 63 fd ff ff jmpq 0xfffffd6d a: b9 ff ff ff ff mov $0xffffffff,%ecx f: ba 08 00 00 00 mov $0x8,%edx 14: 4d 8b 03 mov (%r11),%r8 17: 48 0f bd ca bsr %rdx,%rcx 1b: 49 8b 45 00 mov 0x0(%r13),%rax 1f: 48 63 c9 movslq %ecx,%rcx 22: e9 64 ff ff ff jmpq 0xffffff8b 27: 0f 1f 00 nopl (%rax) * 2a: 65 8b 05 49 ab 8a 7e mov %gs:0x7e8aab49(%rip),%eax # 0x7e8aab7a <-- trapping instruction 31: 89 c1 mov %eax,%ecx 33: 48 8b 34 24 mov (%rsp),%rsi 37: 81 e1 00 01 00 00 and $0x100,%ecx 3d: 65 gs 3e: 48 rex.W 3f: 8b .byte 0x8b