INFO: task systemd-udevd:2969 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:22616 pid: 2969 ppid: 1 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 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_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: 0033:0x7f1576267840 RSP: 002b:00007ffe7aa6d448 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007ffe7aa6d500 RCX: 00007f1576267840 RDX: 000056006c478fe3 RSI: 00000000000a0800 RDI: 000056006daffa90 RBP: 0000000000000000 R08: 000056006c478670 R09: 0000000000000010 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe7aa6d5f0 R13: 000056006dae3010 R14: 000056006db0d4d0 R15: 00007ffe7aa6d4c0 INFO: task syz-executor.2:6569 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.2 state:D stack:23928 pid: 6569 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 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 deactivate_locked_super+0x94/0x160 fs/super.c:335 deactivate_super+0xad/0xd0 fs/super.c:366 cleanup_mnt+0x3a2/0x540 fs/namespace.c:1137 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: 0033:0x7f34336d6f57 RSP: 002b:00007fff306ddd28 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f34336d6f57 RDX: 00007fff306dddfb RSI: 000000000000000a RDI: 00007fff306dddf0 RBP: 00007fff306dddf0 R08: 00000000ffffffff R09: 00007fff306ddbc0 R10: 0000555555b45903 R11: 0000000000000246 R12: 00007f343372f105 R13: 00007fff306deeb0 R14: 0000555555b45810 R15: 00007fff306deef0 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 3 locks held by systemd-journal/2967: 1 lock held by systemd-udevd/2969: #0: ffff88801abbd918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb50 block/bdev.c:819 1 lock held by in:imklog/6233: #0: ffff88801c1deaf0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 2 locks held by syz-executor.2/6569: #0: ffff88801abbd918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x97/0x9e0 block/bdev.c:914 #1: ffff88801abb9360 (&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: 14 Comm: rcu_preempt Not tainted 5.16.0-rc1-next-20211118-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3695 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3714 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3769 [inline] RIP: 0010:__lock_acquire+0x16ab/0x54a0 kernel/locking/lockdep.c:5027 Code: db 74 58 48 83 eb 08 74 52 48 ba 00 00 00 00 00 fc ff df eb 06 48 83 eb 08 74 40 48 8d 7b 18 48 89 f8 48 c1 e8 03 80 3c 10 00 <0f> 85 31 2a 00 00 48 8b 43 18 49 39 c7 0f 84 ec f5 ff ff 48 8d 7b RSP: 0018:ffffc90000d37a38 EFLAGS: 00000046 RAX: 1ffffffff1e57ccb RBX: ffffffff8f2be640 RCX: ffffffff815c685f RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff8f2be658 RBP: 0000000000007fc8 R08: 0000000000000000 R09: ffffffff8ff72a17 R10: fffffbfff1fee542 R11: 0000000000000001 R12: ffff8880119527a8 R13: ffff888011951d40 R14: 0000000000000001 R15: 62386d250e98b09e FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f18ff76e000 CR3: 000000001b5ee000 CR4: 00000000003526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5637 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602 del_timer_sync+0x5b/0x1b0 kernel/time/timer.c:1364 schedule_timeout+0x152/0x2a0 kernel/time/timer.c:1882 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: db 74 58 48 (bad) 0x48(%rax,%rbx,2) 4: 83 eb 08 sub $0x8,%ebx 7: 74 52 je 0x5b 9: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 10: fc ff df 13: eb 06 jmp 0x1b 15: 48 83 eb 08 sub $0x8,%rbx 19: 74 40 je 0x5b 1b: 48 8d 7b 18 lea 0x18(%rbx),%rdi 1f: 48 89 f8 mov %rdi,%rax 22: 48 c1 e8 03 shr $0x3,%rax 26: 80 3c 10 00 cmpb $0x0,(%rax,%rdx,1) * 2a: 0f 85 31 2a 00 00 jne 0x2a61 <-- trapping instruction 30: 48 8b 43 18 mov 0x18(%rbx),%rax 34: 49 39 c7 cmp %rax,%r15 37: 0f 84 ec f5 ff ff je 0xfffff629 3d: 48 rex.W 3e: 8d .byte 0x8d 3f: 7b .byte 0x7b