input: syz0 as /devices/virtual/input/input100 audit: type=1400 audit(1555608527.026:41): avc: denied { map } for pid=6725 comm="syz-executor.4" path="/root/syzkaller-testdir166015357/syzkaller.BMbOQ6/152/file0/bus" dev="ramfs" ino=19189 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:ramfs_t:s0 tclass=file permissive=1 INFO: task syz-executor.0:1833 blocked for more than 140 seconds. Not tainted 4.14.112+ #56 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D25160 1833 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 loop_probe+0x73/0x180 drivers/block/loop.c:1962 kobj_lookup+0x226/0x410 drivers/base/map.c:124 get_gendisk+0x36/0x240 block/genhd.c:785 __blkdev_get+0x345/0xf90 fs/block_dev.c:1451 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xdf0 fs/open.c:770 vfs_open+0x105/0x230 fs/open.c:884 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1077 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task syz-executor.1:1837 blocked for more than 140 seconds. Not tainted 4.14.112+ #56 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D25592 1837 1827 0x00000000 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xdf0 fs/open.c:770 vfs_open+0x105/0x230 fs/open.c:884 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1077 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task syz-executor.3:1846 blocked for more than 140 seconds. Not tainted 4.14.112+ #56 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D25640 1846 1829 0x00000000 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xdf0 fs/open.c:770 vfs_open+0x105/0x230 fs/open.c:884 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1077 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task syz-executor.2:6675 blocked for more than 140 seconds. Not tainted 4.14.112+ #56 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28808 6675 1843 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 blkdev_put+0x27/0x4c0 fs/block_dev.c:1814 blkdev_close+0x86/0xb0 fs/block_dev.c:1863 __fput+0x25e/0x700 fs/file_table.c:210 task_work_run+0x118/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x13b/0x160 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:267 [inline] do_syscall_64+0x372/0x4b0 arch/x86/entry/common.c:294 INFO: task syz-executor.2:6678 blocked for more than 140 seconds. Not tainted 4.14.112+ #56 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D26520 6678 1843 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_release+0x19/0x190 drivers/block/loop.c:1667 __blkdev_put+0x518/0x6d0 fs/block_dev.c:1791 kill_f2fs_super+0x203/0x2f0 fs/f2fs/super.c:3528 deactivate_locked_super+0x71/0xd0 fs/super.c:319 mount_bdev+0x322/0x360 fs/super.c:1151 mount_fs+0x277/0x312 fs/super.c:1255 vfs_kern_mount.part.0+0xc7/0x4a0 fs/namespace.c:1056 vfs_kern_mount fs/namespace.c:1038 [inline] do_new_mount fs/namespace.c:2573 [inline] do_mount+0x3f6/0x26a0 fs/namespace.c:2903 SYSC_mount fs/namespace.c:3119 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3096 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task syz-executor.5:6709 blocked for more than 140 seconds. Not tainted 4.14.112+ #56 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28304 6709 1831 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 loop_reread_partitions+0x72/0x80 drivers/block/loop.c:615 loop_set_status+0xbff/0x11f0 drivers/block/loop.c:1184 INFO: task syz-executor.5:6730 blocked for more than 140 seconds. Not tainted 4.14.112+ #56 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28968 6730 1831 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 loop_control_ioctl+0x71/0x2e0 drivers/block/loop.c:1982 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0xabe/0x1040 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task blkid:6698 blocked for more than 140 seconds. Not tainted 4.14.112+ #56 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28808 6698 2781 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 __lo_release drivers/block/loop.c:1644 [inline] lo_release+0x78/0x190 drivers/block/loop.c:1668 __blkdev_put+0x518/0x6d0 fs/block_dev.c:1791 blkdev_close+0x86/0xb0 fs/block_dev.c:1863 __fput+0x25e/0x700 fs/file_table.c:210 task_work_run+0x118/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x13b/0x160 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:267 [inline] do_syscall_64+0x372/0x4b0 arch/x86/entry/common.c:294 INFO: task blkid:6715 blocked for more than 140 seconds. Not tainted 4.14.112+ #56 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D27800 6715 295 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xdf0 fs/open.c:770 vfs_open+0x105/0x230 fs/open.c:884 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1077 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task blkid:6717 blocked for more than 140 seconds. Not tainted 4.14.112+ #56 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D27800 6717 296 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x963/0xf90 fs/block_dev.c:1537 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xdf0 fs/open.c:770 vfs_open+0x105/0x230 fs/open.c:884 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1077 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: (tasklist_lock){.+.+}, at: [<00000000f7cac0f5>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4544 2 locks held by getty/1756: #0: (&tty->ldisc_sem){++++}, at: [<000000001f2f07a8>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000104cb11a>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.0/1833: #0: (loop_index_mutex){+.+.}, at: [<00000000688e0516>] loop_probe+0x73/0x180 drivers/block/loop.c:1962 1 lock held by syz-executor.1/1837: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000f6cf59ba>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 1 lock held by syz-executor.3/1846: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000f6cf59ba>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 1 lock held by syz-executor.2/6675: #0: (&bdev->bd_mutex){+.+.}, at: [<000000001ea539e7>] blkdev_put+0x27/0x4c0 fs/block_dev.c:1814 2 locks held by syz-executor.2/6678: #0: (&bdev->bd_mutex){+.+.}, at: [<000000003ef4bcc9>] __blkdev_put+0xb1/0x6d0 fs/block_dev.c:1778 #1: (loop_index_mutex){+.+.}, at: [<0000000078251641>] lo_release+0x19/0x190 drivers/block/loop.c:1667 1 lock held by syz-executor.5/6697: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000f6cf59ba>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 2 locks held by syz-executor.5/6709: #0: (loop_ctl_mutex/1){+.+.}, at: [<000000006b57eb08>] lo_ioctl+0x83/0x1970 drivers/block/loop.c:1405 #1: (&bdev->bd_mutex){+.+.}, at: [<0000000045204d1f>] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 1 lock held by syz-executor.5/6712: #0: (loop_index_mutex){+.+.}, at: [<00000000d6f99683>] loop_control_ioctl+0x71/0x2e0 drivers/block/loop.c:1982 1 lock held by syz-executor.5/6730: #0: (loop_index_mutex){+.+.}, at: [<00000000d6f99683>] loop_control_ioctl+0x71/0x2e0 drivers/block/loop.c:1982 1 lock held by syz-executor.5/6732: #0: (loop_index_mutex){+.+.}, at: [<00000000d6f99683>] loop_control_ioctl+0x71/0x2e0 drivers/block/loop.c:1982 3 locks held by blkid/6698: #0: (&bdev->bd_mutex){+.+.}, at: [<000000003ef4bcc9>] __blkdev_put+0xb1/0x6d0 fs/block_dev.c:1778 #1: (loop_index_mutex){+.+.}, at: [<0000000078251641>] lo_release+0x19/0x190 drivers/block/loop.c:1667 #2: (loop_ctl_mutex#2){+.+.}, at: [<00000000c200787f>] __lo_release drivers/block/loop.c:1644 [inline] #2: (loop_ctl_mutex#2){+.+.}, at: [<00000000c200787f>] lo_release+0x78/0x190 drivers/block/loop.c:1668 2 locks held by blkid/6715: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000f6cf59ba>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<0000000097d9e11a>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by blkid/6717: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000f6cf59ba>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<0000000097d9e11a>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 1 lock held by blkid/6722: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000f6cf59ba>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.112+ #56 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x10e lib/dump_stack.c:53 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff94a4a942