INFO: task syz-executor.1:8001 blocked for more than 143 seconds. Not tainted 5.16.0-rc1-next-20211118-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.1 state:D stack:23416 pid: 8001 ppid: 1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4987 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6268 schedule+0xd2/0x260 kernel/sched/core.c:6341 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6400 __mutex_lock_common kernel/locking/mutex.c:680 [inline] __mutex_lock+0xa32/0x12f0 kernel/locking/mutex.c:740 blkdev_get_by_dev.part.0+0x9b/0xb50 block/bdev.c:819 blkdev_get_by_dev+0x6b/0x80 block/bdev.c:859 blkdev_open+0x154/0x2e0 block/fops.c:501 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: 0033:0x7f49557dda04 RSP: 002b:00007ffde871a4b0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffde871a5b0 RCX: 00007f49557dda04 RDX: 0000000000000002 RSI: 00007ffde871a5f0 RDI: 00000000ffffff9c RBP: 00007ffde871a5f0 R08: 0000000000000000 R09: 00007ffde871a3c0 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 0000000000000000 R14: 000000000000000d R15: 00007ffde871a5f0 INFO: task systemd-udevd:11020 blocked for more than 143 seconds. Not tainted 5.16.0-rc1-next-20211118-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:systemd-udevd state:D stack:26896 pid:11020 ppid: 2971 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:4987 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6268 schedule+0xd2/0x260 kernel/sched/core.c:6341 blk_mq_freeze_queue_wait+0x112/0x160 block/blk-mq.c:178 __loop_clr_fd+0x1ae/0x1070 drivers/block/loop.c:1122 lo_release+0x1ac/0x1f0 drivers/block/loop.c:1761 blkdev_put_whole block/bdev.c:694 [inline] blkdev_put+0x2fb/0x9e0 block/bdev.c:956 blkdev_close+0x6a/0x80 block/fops.c:515 __fput+0x286/0x9f0 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207 __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: 0033:0x7fc2f5419270 RSP: 002b:00007ffea5f0df78 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007fc2f5419270 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007 RBP: 00007fc2f62d3710 R08: 000055d34e6f70d0 R09: 000055d34e6f6e00 R10: 00007fc2f62d38c0 R11: 0000000000000246 R12: 0000000000000000 R13: 000055d34e6f3d70 R14: 0000000000000003 R15: 000000000000000e Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb83ba0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 5 locks held by kworker/u4:4/1042: 3 locks held by in:imklog/6256: #0: ffff88807a9194f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 #1: ffffffff8bb83ba0 (rcu_read_lock){....}-{1:2}, at: raw_spin_rq_lock_nested+0x2b/0x120 kernel/sched/core.c:478 #2: ffff8880b9d279c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: trace_sched_stat_runtime include/trace/events/sched.h:517 [inline] #2: ffff8880b9d279c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: update_curr+0x370/0x900 kernel/sched/fair.c:876 1 lock held by syz-executor.1/8001: #0: ffff88801ab68918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb50 block/bdev.c:819 2 locks held by systemd-udevd/11020: #0: ffff88801ab68918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x97/0x9e0 block/bdev.c:914 #1: ffff88801ab14b60 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x7a/0x1070 drivers/block/loop.c:1106 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.16.0-rc1-next-20211118-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:254 [inline] watchdog+0xcb7/0xed0 kernel/hung_task.c:339 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: 1042 Comm: kworker/u4:4 Not tainted 5.16.0-rc1-next-20211118-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: 0x0 (phy7) RIP: 0010:pwq_dec_nr_in_flight+0x20/0x2a0 kernel/workqueue.c:1192 Code: e9 5b ff ff ff 0f 1f 44 00 00 41 55 41 54 55 48 89 fd 53 48 89 f3 e8 8f 7c 2b 00 49 89 dc 83 e3 02 31 ff 49 c1 ec 05 48 89 de 0b 7f 2b 00 41 83 e4 0f 48 85 db 0f 85 a5 00 00 00 e8 69 7c 2b RSP: 0018:ffffc90005507cf8 EFLAGS: 00000802 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff88801c6c3a80 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88802292a800 R08: 0000000000000000 R09: 0000000000000003 R10: ffffffff814c3509 R11: 0000000000000000 R12: 07fffc4401149540 R13: ffff88806ed597d8 R14: ffff88801b57e700 R15: ffff888010c69800 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb6587ee000 CR3: 000000001c935000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: process_one_work+0xc9c/0x1690 kernel/workqueue.c:2341 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: e9 5b ff ff ff jmpq 0xffffff60 5: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) a: 41 55 push %r13 c: 41 54 push %r12 e: 55 push %rbp f: 48 89 fd mov %rdi,%rbp 12: 53 push %rbx 13: 48 89 f3 mov %rsi,%rbx 16: e8 8f 7c 2b 00 callq 0x2b7caa 1b: 49 89 dc mov %rbx,%r12 1e: 83 e3 02 and $0x2,%ebx 21: 31 ff xor %edi,%edi 23: 49 c1 ec 05 shr $0x5,%r12 27: 48 89 de mov %rbx,%rsi * 2a: e8 0b 7f 2b 00 callq 0x2b7f3a <-- trapping instruction 2f: 41 83 e4 0f and $0xf,%r12d 33: 48 85 db test %rbx,%rbx 36: 0f 85 a5 00 00 00 jne 0xe1 3c: e8 .byte 0xe8 3d: 69 .byte 0x69 3e: 7c 2b jl 0x6b