audit: type=1400 audit(1556427703.285:5): avc: denied { associate } for pid=2234 comm="syz-executor.0" name="syz0" scontext=unconfined_u:object_r:unlabeled_t:s0 tcontext=system_u:object_r:unlabeled_t:s0 tclass=filesystem permissive=1 INFO: task syz-executor.4:2231 blocked for more than 140 seconds. Not tainted 4.9.170+ #48 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D25400 2231 1 0x00000004 ffff8801c9a117c0 ffff8801c9c03c80 ffff8801db621000 ffff8801c9e517c0 ffff8801db621018 ffff8801c9f77688 ffffffff82801a4e ffff8801c9a117c0 ffffffff841f38c0 00ff8801c9f775e8 ffff8801db6218f0 1ffff100393eeec0 Call Trace: [<000000002e814d85>] schedule+0x92/0x1c0 kernel/sched/core.c:3546 [<00000000390dd9dd>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3579 [<00000000184a54ef>] __mutex_lock_common kernel/locking/mutex.c:582 [inline] [<00000000184a54ef>] mutex_lock_nested+0x38d/0x920 kernel/locking/mutex.c:621 [<000000007373da6c>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 [<00000000ae980f6b>] __blkdev_get+0x268/0xeb0 fs/block_dev.c:1287 [<0000000033100c56>] blkdev_get+0x2e8/0x920 fs/block_dev.c:1424 [<00000000fbcbf737>] blkdev_open+0x1aa/0x250 fs/block_dev.c:1579 [<00000000c8b43b8d>] do_dentry_open+0x422/0xd20 fs/open.c:772 [<00000000a48dea38>] vfs_open+0x105/0x230 fs/open.c:885 [<000000003c5b90e1>] do_last fs/namei.c:3457 [inline] [<000000003c5b90e1>] path_openat+0xbf5/0x2f60 fs/namei.c:3581 [<00000000bcc0e41b>] do_filp_open+0x1a1/0x280 fs/namei.c:3615 [<00000000f5f8cce8>] do_sys_open+0x2f0/0x610 fs/open.c:1078 [<00000000ac136b5e>] SYSC_open fs/open.c:1096 [inline] [<00000000ac136b5e>] SyS_open+0x2d/0x40 fs/open.c:1091 [<00000000d9906bd2>] do_syscall_64+0x1ad/0x570 arch/x86/entry/common.c:285 [<000000004ffb63f1>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Showing all locks held in the system: 2 locks held by khungtaskd/24: #0: (rcu_read_lock){......}, at: [<0000000028e26b4e>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline] #0: (rcu_read_lock){......}, at: [<0000000028e26b4e>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263 #1: (tasklist_lock){.+.+..}, at: [<0000000004eb4356>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4339 1 lock held by rsyslogd/1894: #0: (&f->f_pos_lock){+.+.+.}, at: [<000000007dbb0d5d>] __fdget_pos+0xa8/0xd0 fs/file.c:782 2 locks held by getty/2022: #0: (&tty->ldisc_sem){++++++}, at: [<00000000d5d0df27>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+...}, at: [<00000000bc39a82e>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.4/2231: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000001c710032>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<000000007373da6c>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 2 locks held by syz-executor.2/2232: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000001c710032>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<000000007373da6c>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 1 lock held by syz-executor.0/2234: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000001c710032>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 3 locks held by syz-executor.3/2238: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000007a219060>] __blkdev_put+0xbb/0x840 fs/block_dev.c:1587 #1: (loop_index_mutex){+.+.+.}, at: [<000000004ec1b06c>] lo_release+0x1e/0x1b0 drivers/block/loop.c:1664 #2: (loop_ctl_mutex#2){+.+...}, at: [<00000000cf24b952>] __lo_release drivers/block/loop.c:1642 [inline] #2: (loop_ctl_mutex#2){+.+...}, at: [<00000000cf24b952>] lo_release+0x84/0x1b0 drivers/block/loop.c:1665 2 locks held by syz-executor.1/3112: #0: (loop_ctl_mutex/1){+.+.+.}, at: [<000000009c109077>] lo_ioctl+0x85/0x1a10 drivers/block/loop.c:1405 #1: (&bdev->bd_mutex){+.+.+.}, at: [<00000000e3d2970c>] blkdev_reread_part+0x1f/0x40 block/ioctl.c:189 1 lock held by blkid/3113: #0: (loop_ctl_mutex/1){+.+.+.}, at: [<000000009c109077>] lo_ioctl+0x85/0x1a10 drivers/block/loop.c:1405 1 lock held by syz-executor.5/3115: #0: (loop_ctl_mutex/1){+.+.+.}, at: [<000000009c109077>] lo_ioctl+0x85/0x1a10 drivers/block/loop.c:1405 2 locks held by blkid/3116: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000001c710032>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<000000007373da6c>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 2 locks held by blkid/3122: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000001c710032>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<000000007373da6c>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 1 lock held by blkid/3123: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000001c710032>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.170+ #48 ffff8801d98d7cc8 ffffffff81b4fb21 0000000000000000 0000000000000000 0000000000000000 ffffffff81097401 dffffc0000000000 ffff8801d98d7d00 ffffffff81b5adbc 0000000000000000 0000000000000000 0000000000000000 Call Trace: [<0000000067df848e>] __dump_stack lib/dump_stack.c:15 [inline] [<0000000067df848e>] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [<000000004fd051fa>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99 [<00000000c793706b>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60 [<000000004140beb0>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [<0000000013ea9b82>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [<0000000013ea9b82>] check_hung_task kernel/hung_task.c:126 [inline] [<0000000013ea9b82>] check_hung_uninterruptible_tasks kernel/hung_task.c:183 [inline] [<0000000013ea9b82>] watchdog+0x670/0xaf0 kernel/hung_task.c:263 [<0000000021a12a60>] kthread+0x278/0x310 kernel/kthread.c:211 [<000000005589c201>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff82810ac2