INFO: task syz-executor.2:11165 blocked for more than 140 seconds. Not tainted 4.14.216-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28536 11165 8006 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 loop_control_ioctl+0x181/0x3f0 drivers/block/loop.c:2007 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45e219 RSP: 002b:00007f436234cc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045e219 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003 RBP: 000000000119bfc0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007ffe5bb4526f R14: 00007f436234d9c0 R15: 000000000119bf8c INFO: task syz-executor.0:11168 blocked for more than 140 seconds. Not tainted 4.14.216-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29248 11168 8003 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 loop_reread_partitions drivers/block/loop.c:624 [inline] loop_set_status+0xeeb/0x12b0 drivers/block/loop.c:1193 loop_set_status64+0x92/0xe0 drivers/block/loop.c:1311 lo_ioctl+0x587/0x1cd0 drivers/block/loop.c:1441 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x540/0x1830 block/ioctl.c:594 block_ioctl+0xd9/0x120 fs/block_dev.c:1893 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45e087 RSP: 002b:00007f5ae85779e8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 000000000045e087 RDX: 00007f5ae8577ab0 RSI: 0000000000004c04 RDI: 0000000000000004 RBP: 000000000119bfc0 R08: 0000000020000030 R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000202 R12: 000000000119bf8c R13: 00007ffdeb9123af R14: 00007f5ae85789c0 R15: 000000000119bf8c INFO: task systemd-udevd:11171 blocked for more than 140 seconds. Not tainted 4.14.216-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. systemd-udevd D28912 11171 4629 0x00000104 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1634 __blkdev_get+0xa8c/0x1090 fs/block_dev.c:1537 blkdev_get+0x88/0x890 fs/block_dev.c:1611 blkdev_open+0x1cc/0x250 fs/block_dev.c:1772 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0x628/0x2970 fs/namei.c:3569 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f94f7c87840 RSP: 002b:00007fffc6153a48 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000055d13cec55a0 RCX: 00007f94f7c87840 RDX: 000055d13af81fe3 RSI: 0000000000080000 RDI: 000055d13cecb530 RBP: 0000000000000001 R08: 000055d13af81670 R09: 0000000000000110 R10: 00000000000002fe R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 000055d13ceb7720 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1531: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 2 locks held by syz-executor.2/11165: #0: (loop_index_mutex){+.+.}, at: [] loop_control_ioctl+0x67/0x3f0 drivers/block/loop.c:1993 #1: (&lo->lo_ctl_mutex){+.+.}, at: [] loop_control_ioctl+0x181/0x3f0 drivers/block/loop.c:2007 2 locks held by syz-executor.0/11168: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x87/0x1cd0 drivers/block/loop.c:1414 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 2 locks held by systemd-udevd/11171: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x191/0x1090 fs/block_dev.c:1455 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x19/0xb0 drivers/block/loop.c:1634 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1531 Comm: khungtaskd Not tainted 4.14.216-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5b9/0xb40 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4622 Comm: systemd-journal Not tainted 4.14.216-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880a16980c0 task.stack: ffff8880a16a0000 RIP: 0010:lock_release+0xc/0x870 kernel/locking/lockdep.c:4007 RSP: 0018:ffff8880a16a7b80 EFLAGS: 00000096 RAX: dffffc0000000000 RBX: 0000000000000082 RCX: ffff8880765f3600 RDX: ffffffff83185db0 RSI: 0000000000000001 RDI: ffffffff8c081b60 RBP: ffffffff8c081b48 R08: 1ffff11016010ca4 R09: 0000000000000082 R10: ffff8880a1698948 R11: ffff8880a16980c0 R12: ffff8880765f2600 R13: 000000000000000a R14: ffffffff8c081b48 R15: ffff8880b0086508 FS: 00007f4233d0d8c0(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f42311e0018 CR3: 00000000a1531000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_unlock_irqrestore+0x1b/0xe0 kernel/locking/spinlock.c:192 __debug_check_no_obj_freed lib/debugobjects.c:760 [inline] debug_check_no_obj_freed+0x2c0/0x680 lib/debugobjects.c:776 kmem_cache_free+0x156/0x2b0 mm/slab.c:3757 putname+0xcd/0x110 fs/namei.c:259 filename_lookup+0x37b/0x510 fs/namei.c:2386 user_path_at include/linux/namei.h:57 [inline] SYSC_faccessat fs/open.c:403 [inline] SyS_faccessat+0x21b/0x680 fs/open.c:353 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f4232fc99c7 RSP: 002b:00007ffeedd37268 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffeedd3a180 RCX: 00007f4232fc99c7 RDX: 00007f4233a3aa00 RSI: 0000000000000000 RDI: 0000558a14d049a3 RBP: 00007ffeedd372a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffeedd3a180 R15: 00007ffeedd37790 Code: 4c 8b 44 24 08 e9 4b fd ff ff 48 c7 c7 40 b9 f9 8b e8 29 ec 3c 00 e9 88 fd ff ff 0f 1f 40 00 48 b8 00 00 00 00 00 fc ff df 41 57 <41> 56 41 55 41 54 49 89 d4 55 48 89 fd 53 48 83 ec 58 48 c7 44