INFO: task syz-executor.3:20849 blocked for more than 143 seconds. Not tainted 5.0.0-next-20190306 #4 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D27272 20849 10596 0x00000004 Call Trace: context_switch kernel/sched/core.c:2877 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3518 schedule+0x92/0x180 kernel/sched/core.c:3562 request_wait_answer+0x42f/0x7c0 fs/fuse/dev.c:554 __fuse_request_send+0x12b/0x1d0 fs/fuse/dev.c:574 fuse_request_send+0x60/0xa0 fs/fuse/dev.c:587 fuse_simple_request+0x2f6/0x740 fs/fuse/dev.c:645 fuse_do_getattr+0x24b/0xc80 fs/fuse/dir.c:895 fuse_perm_getattr+0x3d/0x60 fs/fuse/dir.c:1078 fuse_permission+0x3d5/0x530 fs/fuse/dir.c:1115 do_inode_permission fs/namei.c:384 [inline] inode_permission+0x36d/0x570 fs/namei.c:449 may_lookup fs/namei.c:1700 [inline] link_path_walk.part.0+0x9d6/0x1340 fs/namei.c:2082 link_path_walk fs/namei.c:2070 [inline] path_openat+0x202/0x46e0 fs/namei.c:3532 do_filp_open+0x1a1/0x280 fs/namei.c:3563 do_sys_open+0x3fe/0x5d0 fs/open.c:1063 __do_sys_openat fs/open.c:1090 [inline] __se_sys_openat fs/open.c:1084 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1084 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458079 Code: Bad RIP value. RSP: 002b:00007fded4176c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000458079 RDX: 0000000000000002 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fded41776d4 R13: 00000000004c40f2 R14: 00000000004d75b8 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1044: #0: 0000000080490dbb (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5052 2 locks held by rsyslogd/7666: #0: 0000000070120d51 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 #1: 00000000b65579a8 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1168 [inline] #1: 00000000b65579a8 (&rq->lock){-.-.}, at: __schedule+0x1fc/0x1cc0 kernel/sched/core.c:3456 2 locks held by getty/7756: #0: 00000000e0cf406d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000b5178f03 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7757: #0: 000000003831ad5a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000de714ce9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7758: #0: 000000003c987970 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000012eadd6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7759: #0: 000000008de93809 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000a317b497 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7760: #0: 000000003008c947 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000005855450c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7761: #0: 000000000148b0cf (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000a2140ea7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7762: #0: 000000007db0cbef (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000009d858b0e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by kworker/u4:6/8710: #0: 00000000b65579a8 (&rq->lock){-.-.}, at: idle_balance kernel/sched/fair.c:10011 [inline] #0: 00000000b65579a8 (&rq->lock){-.-.}, at: pick_next_task_fair+0x1214/0x19a0 kernel/sched/fair.c:7062 #1: 0000000080490dbb (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:6059 1 lock held by syz-executor.4/12392: #0: 00000000c6421c82 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1407 [inline] #0: 00000000c6421c82 (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file.isra.0+0x376/0x23f0 fs/exec.c:1750 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1044 Comm: khungtaskd Not tainted 5.0.0-next-20190306 #4 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0x9b7/0xec0 kernel/hung_task.c:288 kthread+0x357/0x430 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: