audit: type=1400 audit(2000000150.320:1818): avc: denied { write } for pid=16003 comm="syz-executor.5" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 INFO: task syz-executor.1:11722 blocked for more than 140 seconds. Not tainted 4.9.155+ #27 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D25512 11722 1 0x00000004 ffff8801a4a48000 ffff8801a2eec200 ffff8801db721000 ffff8801a3288000 ffff8801db721018 ffff8801a3eef598 ffffffff82806806 f7976ee33eb8cd3d 0000000000000001 ffff8801a4a488b0 0000000000000006 ffff8801db7218f0 Call Trace: [] schedule+0x92/0x1c0 kernel/sched/core.c:3553 [] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3586 [] __mutex_lock_common kernel/locking/mutex.c:582 [inline] [] mutex_lock_nested+0x38d/0x920 kernel/locking/mutex.c:621 [] fuse_lock_inode+0xad/0xe0 fs/fuse/inode.c:364 [] fuse_lookup+0x89/0x3b0 fs/fuse/dir.c:406 [] lookup_slow+0x24b/0x480 fs/namei.c:1709 [] walk_component+0x71e/0xce0 fs/namei.c:1825 [] link_path_walk+0x897/0x1200 fs/namei.c:2161 [] path_mountpoint+0x67/0x6d0 fs/namei.c:2737 [] filename_mountpoint+0x17f/0x350 fs/namei.c:2758 [] user_path_mountpoint_at+0x3a/0x50 fs/namei.c:2788 [] SYSC_umount fs/namespace.c:1722 [inline] [] SyS_umount+0x136/0xd30 fs/namespace.c:1706 [] do_syscall_64+0x1ad/0x570 arch/x86/entry/common.c:285 [] 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: [] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline] #0: (rcu_read_lock){......}, at: [] watchdog+0x11b/0xa40 kernel/hung_task.c:239 #1: (tasklist_lock){.+.?..}, at: [] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4336 2 locks held by getty/2032: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.1/11722: #0: (&type->i_mutex_dir_key#7){++++++}, at: [] inode_lock_shared include/linux/fs.h:778 [inline] #0: (&type->i_mutex_dir_key#7){++++++}, at: [] lookup_slow+0x160/0x480 fs/namei.c:1686 #1: (&fi->mutex){+.+.+.}, at: [] fuse_lock_inode+0xad/0xe0 fs/fuse/inode.c:364 2 locks held by syz-executor.1/15951: #0: (&type->i_mutex_dir_key#7){++++++}, at: [] inode_lock_shared include/linux/fs.h:778 [inline] #0: (&type->i_mutex_dir_key#7){++++++}, at: [] lookup_slow+0x160/0x480 fs/namei.c:1686 #1: (&fi->mutex){+.+.+.}, at: [] fuse_lock_inode+0xad/0xe0 fs/fuse/inode.c:364 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.155+ #27 ffff8801d9907cd0 ffffffff81b47871 0000000000000000 0000000000000000 0000000000000000 ffffffff81097301 00000000003ffefc ffff8801d9907d08 ffffffff81b52afc 0000000000000000 0000000000000000 0000000000000000 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99 [] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60 [] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [] check_hung_task kernel/hung_task.c:125 [inline] [] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline] [] watchdog+0x5f7/0xa40 kernel/hung_task.c:239 [] kthread+0x278/0x310 kernel/kthread.c:211 [] 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 0xffffffff82815692