INFO: task syz-executor.4:6574 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.4 state:D stack:23920 pid: 6574 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: 0033:0x7f13c6b5df57 RSP: 002b:00007ffda15ed348 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f13c6b5df57 RDX: 00007ffda15ed41b RSI: 000000000000000a RDI: 00007ffda15ed410 RBP: 00007ffda15ed410 R08: 00000000ffffffff R09: 00007ffda15ed1e0 R10: 000055555666e903 R11: 0000000000000246 R12: 00007f13c6bb6105 R13: 00007ffda15ee4d0 R14: 000055555666e810 R15: 00007ffda15ee510 INFO: task systemd-udevd:3294 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:26144 pid: 3294 ppid: 2976 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: 0033:0x7fd10121b840 RSP: 002b:00007fff930e2128 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00005647539183a0 RCX: 00007fd10121b840 RDX: 0000564752071fe3 RSI: 00000000000a0800 RDI: 0000564753904de0 RBP: 00007fff930e22a0 R08: 0000564752071670 R09: 0000000000000010 R10: 0000564752071d0c R11: 0000000000000246 R12: 00007fff930e21f0 R13: 0000564753904e40 R14: 0000000000000003 R15: 000000000000000e Showing all locks held in the system: 1 lock held by khungtaskd/26: #0: ffffffff8bb83ba0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by in:imklog/6220: #0: ffff888072778d70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 2 locks held by syz-executor.4/6574: #0: ffff88801ab69118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x97/0x9e0 block/bdev.c:914 #1: ffff88801ab4cb60 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x7a/0x1070 drivers/block/loop.c:1106 3 locks held by kworker/u4:9/25082: 1 lock held by systemd-udevd/3294: #0: ffff88801ab69118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb50 block/bdev.c:819 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 26 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: 2967 Comm: systemd-journal 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:check_preemption_disabled+0xa/0x170 lib/smp_processor_id.c:13 Code: f8 65 48 8b 3c 25 40 70 02 00 e8 a1 99 11 f8 eb 99 0f 1f 44 00 00 0f 0b e9 23 ff ff ff cc cc cc 41 56 41 55 49 89 f5 41 54 55 <48> 89 fd 53 0f 1f 44 00 00 65 44 8b 25 0d d0 c0 76 65 8b 1d 7e 2a RSP: 0018:ffffc9000202f980 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff89ac1080 RDI: ffffffff8a04b6a0 RBP: ffffffff8bb83ae0 R08: 0000000000000000 R09: ffffffff8d90e7d7 R10: fffffbfff1b21cfa R11: 000000000000002f R12: ffff88807ad43a80 R13: ffffffff89ac1080 R14: 00000000ffffffff R15: ffff88807ad44510 FS: 00007f04603cd8c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f045cba9020 CR3: 000000001aa1a000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:438 [inline] lock_is_held_type+0xd7/0x140 kernel/locking/lockdep.c:5681 lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x522/0x720 kernel/locking/lockdep.c:5648 seqcount_lockdep_reader_access include/linux/seqlock.h:104 [inline] set_root+0x3ca/0x5b0 fs/namei.c:940 nd_jump_root+0x3c8/0x570 fs/namei.c:961 path_init+0x1020/0x1920 fs/namei.c:2359 path_lookupat+0x30/0x860 fs/namei.c:2439 filename_lookup+0x1c6/0x590 fs/namei.c:2478 user_path_at_empty+0x42/0x60 fs/namei.c:2801 user_path_at include/linux/namei.h:57 [inline] do_faccessat+0x127/0x850 fs/open.c:421 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: 0033:0x7f045f6889c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd3de49798 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffd3de4c6b0 RCX: 00007f045f6889c7 RDX: 00007f04600f9a00 RSI: 0000000000000000 RDI: 00005623be9f99a3 RBP: 00007ffd3de497d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffd3de4c6b0 R15: 00007ffd3de49cc0 ---------------- Code disassembly (best guess): 0: f8 clc 1: 65 48 8b 3c 25 40 70 mov %gs:0x27040,%rdi 8: 02 00 a: e8 a1 99 11 f8 callq 0xf81199b0 f: eb 99 jmp 0xffffffaa 11: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 16: 0f 0b ud2 18: e9 23 ff ff ff jmpq 0xffffff40 1d: cc int3 1e: cc int3 1f: cc int3 20: 41 56 push %r14 22: 41 55 push %r13 24: 49 89 f5 mov %rsi,%r13 27: 41 54 push %r12 29: 55 push %rbp * 2a: 48 89 fd mov %rdi,%rbp <-- trapping instruction 2d: 53 push %rbx 2e: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 33: 65 44 8b 25 0d d0 c0 mov %gs:0x76c0d00d(%rip),%r12d # 0x76c0d048 3a: 76 3b: 65 gs 3c: 8b .byte 0x8b 3d: 1d .byte 0x1d 3e: 7e 2a jle 0x6a