INFO: task syz-executor.5:6934 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.5 state:D stack:20152 pid: 6934 ppid: 1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4969 [inline] __schedule+0xb72/0x1460 kernel/sched/core.c:6250 schedule+0x12b/0x1f0 kernel/sched/core.c:6323 blk_mq_freeze_queue_wait+0x105/0x190 block/blk-mq.c:178 __loop_clr_fd+0x1c6/0x9b0 drivers/block/loop.c:1122 blkdev_put_whole block/bdev.c:694 [inline] blkdev_put+0x477/0x7b0 block/bdev.c:956 deactivate_locked_super+0xa7/0xf0 fs/super.c:335 cleanup_mnt+0x462/0x510 fs/namespace.c:1137 task_work_run+0x146/0x1c0 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+0x209/0x220 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x2e/0x70 kernel/entry/common.c:300 do_syscall_64+0x53/0xd0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fd39fc94f57 RSP: 002b:00007ffdf3159938 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fd39fc94f57 RDX: 00007ffdf3159a0b RSI: 000000000000000a RDI: 00007ffdf3159a00 RBP: 00007ffdf3159a00 R08: 00000000ffffffff R09: 00007ffdf31597d0 R10: 00005555565ea903 R11: 0000000000000246 R12: 00007fd39fced105 R13: 00007ffdf315aac0 R14: 00005555565ea810 R15: 00007ffdf315ab00 INFO: task systemd-udevd:15125 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:systemd-udevd state:D stack:26864 pid:15125 ppid: 2975 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4969 [inline] __schedule+0xb72/0x1460 kernel/sched/core.c:6250 schedule+0x12b/0x1f0 kernel/sched/core.c:6323 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6382 __mutex_lock_common+0xd1f/0x2590 kernel/locking/mutex.c:680 __mutex_lock kernel/locking/mutex.c:740 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:792 blkdev_get_by_dev+0xfc/0xb80 block/bdev.c:819 blkdev_open+0x137/0x2f0 block/fops.c:501 do_dentry_open+0x78b/0x1020 fs/open.c:822 do_open fs/namei.c:3426 [inline] path_openat+0x2896/0x3660 fs/namei.c:3559 do_filp_open+0x277/0x4f0 fs/namei.c:3586 do_sys_openat2+0x13b/0x500 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+0x221/0x270 fs/open.c:1232 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f298eeb7840 RSP: 002b:00007ffe117c1318 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00005617a63ca380 RCX: 00007f298eeb7840 RDX: 00005617a5955fe3 RSI: 00000000000a0800 RDI: 00005617a63b7520 RBP: 00007ffe117c1490 R08: 00005617a5955670 R09: 0000000000000010 R10: 00005617a5955d0c R11: 0000000000000246 R12: 00007ffe117c13e0 R13: 00005617a63b70d0 R14: 0000000000000003 R15: 000000000000000e Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8cb1da00 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by syz-executor.1/6518: #0: ffff8881474b0118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xfa/0x7b0 block/bdev.c:914 #1: ffff88801ab7bb60 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x6d/0x9b0 drivers/block/loop.c:1106 2 locks held by syz-executor.4/6536: #0: ffff88801abed918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xfa/0x7b0 block/bdev.c:914 #1: ffff88801abe9360 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x6d/0x9b0 drivers/block/loop.c:1106 2 locks held by syz-executor.5/6934: #0: ffff88801abf2918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xfa/0x7b0 block/bdev.c:914 #1: ffff88801abee360 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x6d/0x9b0 drivers/block/loop.c:1106 1 lock held by systemd-udevd/15125: #0: ffff88801abf2918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0xfc/0xb80 block/bdev.c:819 ============================================= 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+0x1dc/0x2d8 lib/dump_stack.c:106 nmi_cpu_backtrace+0x45f/0x490 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x16a/0x280 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+0xc82/0xcd0 kernel/hung_task.c:295 kthread+0x468/0x490 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 44 Comm: kworker/u4:2 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: 0x0 (phy13) RIP: 0010:vtime_task_switch_generic+0x0/0x580 kernel/sched/cputime.c:765 Code: d0 ff ff 0f 0b 42 80 7c 2d 00 00 75 d6 eb dc 44 89 f9 80 e1 07 80 c1 03 38 c1 7c b9 4c 89 ff e8 76 35 73 00 eb af 0f 1f 40 00 <55> 41 57 41 56 41 55 41 54 53 48 83 ec 28 48 89 fb 48 c7 c0 a4 8a RSP: 0018:ffffc9000114fc18 EFLAGS: 00000002 RAX: 0000000000000001 RBX: ffff88806da70018 RCX: 1ffff92000229f50 RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff88806da70000 RBP: ffffc9000114fc70 R08: dffffc0000000000 R09: ffffed100db4e001 R10: ffffed100db4e001 R11: 0000000000000000 R12: ffff8880b9b00000 R13: ffff8880b9b39ff8 R14: dffffc0000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8a3cd5b000 CR3: 000000000c88e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vtime_task_switch include/linux/vtime.h:95 [inline] finish_task_switch+0x3f5/0x630 kernel/sched/core.c:4843 context_switch kernel/sched/core.c:4972 [inline] __schedule+0xb7a/0x1460 kernel/sched/core.c:6250 schedule+0x12b/0x1f0 kernel/sched/core.c:6323 worker_thread+0xfd5/0x1320 kernel/workqueue.c:2466 kthread+0x468/0x490 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 ---------------- Code disassembly (best guess): 0: d0 ff sar %bh 2: ff 0f decl (%rdi) 4: 0b 42 80 or -0x80(%rdx),%eax 7: 7c 2d jl 0x36 9: 00 00 add %al,(%rax) b: 75 d6 jne 0xffffffe3 d: eb dc jmp 0xffffffeb f: 44 89 f9 mov %r15d,%ecx 12: 80 e1 07 and $0x7,%cl 15: 80 c1 03 add $0x3,%cl 18: 38 c1 cmp %al,%cl 1a: 7c b9 jl 0xffffffd5 1c: 4c 89 ff mov %r15,%rdi 1f: e8 76 35 73 00 callq 0x73359a 24: eb af jmp 0xffffffd5 26: 0f 1f 40 00 nopl 0x0(%rax) * 2a: 55 push %rbp <-- trapping instruction 2b: 41 57 push %r15 2d: 41 56 push %r14 2f: 41 55 push %r13 31: 41 54 push %r12 33: 53 push %rbx 34: 48 83 ec 28 sub $0x28,%rsp 38: 48 89 fb mov %rdi,%rbx 3b: 48 rex.W 3c: c7 .byte 0xc7 3d: c0 .byte 0xc0 3e: a4 movsb %ds:(%rsi),%es:(%rdi) 3f: 8a .byte 0x8a