audit: type=1400 audit(1551550282.847:55): avc: denied { map } for pid=5448 comm="syz-executor.0" path="/sys/kernel/debug/kcov" dev="debugfs" ino=5005 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:debugfs_t:s0 tclass=file permissive=1 INFO: task syz-executor.4:4195 blocked for more than 140 seconds. Not tainted 4.14.104+ #22 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28072 4195 1852 0x80000002 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3492 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3550 __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 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x903/0x2960 kernel/exit.c:873 INFO: task syz-executor.4:4821 blocked for more than 140 seconds. Not tainted 4.14.104+ #22 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28152 4821 1852 0x80000002 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3492 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3550 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_release+0x19/0x170 drivers/block/loop.c:1643 __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 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x903/0x2960 kernel/exit.c:873 INFO: task blkid:5419 blocked for more than 140 seconds. Not tainted 4.14.104+ #22 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28808 5419 2844 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3492 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3550 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_release+0x19/0x170 drivers/block/loop.c:1643 __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 syz-executor.4:5422 blocked for more than 140 seconds. Not tainted 4.14.104+ #22 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28952 5422 1852 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3492 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3550 __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:614 loop_set_status+0xbff/0x11f0 drivers/block/loop.c:1183 INFO: task syz-executor.0:5449 blocked for more than 140 seconds. Not tainted 4.14.104+ #22 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D25640 5449 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3492 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3550 __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+0x41b/0xd60 fs/open.c:764 vfs_open+0x105/0x230 fs/open.c:878 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:1071 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: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4541 2 locks held by getty/1758: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:275 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.4/4195: #0: (&bdev->bd_mutex){+.+.}, at: [] blkdev_put+0x27/0x4c0 fs/block_dev.c:1814 2 locks held by syz-executor.4/4821: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_put+0xb1/0x6d0 fs/block_dev.c:1778 #1: (loop_ctl_mutex){+.+.}, at: [] lo_release+0x19/0x170 drivers/block/loop.c:1643 2 locks held by blkid/5419: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_put+0xb1/0x6d0 fs/block_dev.c:1778 #1: (loop_ctl_mutex){+.+.}, at: [] lo_release+0x19/0x170 drivers/block/loop.c:1643 2 locks held by syz-executor.4/5422: #0: (loop_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x83/0x1970 drivers/block/loop.c:1404 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 1 lock held by syz-executor.0/5449: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: khungtaskd Not tainted 4.14.104+ #22 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 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at pc 0xffffffffb7642a72