INFO: task syz-executor7:26963 blocked for more than 140 seconds. Not tainted 4.18.0-next-20180816+ #41 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D23544 26963 4407 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x87c/0x1df0 kernel/sched/core.c:3473 schedule+0xfb/0x450 kernel/sched/core.c:3517 __rwsem_down_write_failed_common+0x98b/0x1650 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write_nested+0xae/0x130 kernel/locking/rwsem.c:194 inode_lock_nested include/linux/fs.h:805 [inline] do_unlinkat+0x3d8/0xa30 fs/namei.c:4049 __do_sys_unlink fs/namei.c:4110 [inline] __se_sys_unlink fs/namei.c:4108 [inline] __x64_sys_unlink+0x42/0x50 fs/namei.c:4108 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457089 Code: 08 e8 3b a9 fb ff 48 8b 44 24 20 48 8b 4c 24 18 48 8b 54 24 38 48 8b 7c 24 48 eb 8d 48 8b 6c 24 50 48 83 c4 58 c3 48 89 04 24 <48> 89 5c 24 08 e8 0d a9 fb ff 48 8b 44 24 40 48 8b 4c 24 48 48 8b RSP: 002b:00007fad3d194c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 00007fad3d1956d4 RCX: 0000000000457089 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000300 RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d6c80 R14: 00000000004c7a6c R15: 0000000000000001 INFO: task syz-executor7:26965 blocked for more than 140 seconds. Not tainted 4.18.0-next-20180816+ #41 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D25720 26965 4407 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x87c/0x1df0 kernel/sched/core.c:3473 schedule+0xfb/0x450 kernel/sched/core.c:3517 __rwsem_down_write_failed_common+0x98b/0x1650 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write_nested+0xae/0x130 kernel/locking/rwsem.c:194 inode_lock_nested include/linux/fs.h:805 [inline] filename_create+0x1b2/0x5b0 fs/namei.c:3635 user_path_create fs/namei.c:3693 [inline] do_mkdirat+0xda/0x310 fs/namei.c:3832 __do_sys_mkdir fs/namei.c:3856 [inline] __se_sys_mkdir fs/namei.c:3854 [inline] __x64_sys_mkdir+0x5c/0x80 fs/namei.c:3854 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457089 Code: 08 e8 3b a9 fb ff 48 8b 44 24 20 48 8b 4c 24 18 48 8b 54 24 38 48 8b 7c 24 48 eb 8d 48 8b 6c 24 50 48 83 c4 58 c3 48 89 04 24 <48> 89 5c 24 08 e8 0d a9 fb ff 48 8b 44 24 40 48 8b 4c 24 48 48 8b RSP: 002b:00007fad3d152c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00007fad3d1536d4 RCX: 0000000000457089 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200000c0 RBP: 0000000000930280 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d25b8 R14: 00000000004c2680 R15: 0000000000000003 Showing all locks held in the system: 1 lock held by khungtaskd/774: #0: 00000000b02b557b (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4436 1 lock held by rsyslogd/4263: #0: 00000000e4847756 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/4353: #0: 000000000d2195fb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000d7590fa2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4354: #0: 00000000a239525c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000004e036bb4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4355: #0: 00000000a6a9a601 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000c63aaaa3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4356: #0: 00000000658c2029 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000003fe637c6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4357: #0: 0000000051f34a36 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000b9816e00 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4358: #0: 00000000d78863f9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000005b4ab8af (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4359: #0: 0000000068f2a095 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000000eabc3ac (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 3 locks held by syz-executor7/26903: #0: 000000001f1ead00 (sb_writers#19){.+.+}, at: sb_start_write include/linux/fs.h:1598 [inline] #0: 000000001f1ead00 (sb_writers#19){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 #1: 00000000e4e29039 (&sb->s_type->i_mutex_key#21/1){+.+.}, at: inode_lock_nested include/linux/fs.h:805 [inline] #1: 00000000e4e29039 (&sb->s_type->i_mutex_key#21/1){+.+.}, at: do_unlinkat+0x3d8/0xa30 fs/namei.c:4049 #2: 0000000095b53231 (&sb->s_type->i_mutex_key#22){++++}, at: inode_lock include/linux/fs.h:765 [inline] #2: 0000000095b53231 (&sb->s_type->i_mutex_key#22){++++}, at: vfs_unlink+0xd1/0x510 fs/namei.c:3991 2 locks held by syz-executor7/26963: #0: 000000001f1ead00 (sb_writers#19){.+.+}, at: sb_start_write include/linux/fs.h:1598 [inline] #0: 000000001f1ead00 (sb_writers#19){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 #1: 00000000e4e29039 (&sb->s_type->i_mutex_key#21/1){+.+.}, at: inode_lock_nested include/linux/fs.h:805 [inline] #1: 00000000e4e29039 (&sb->s_type->i_mutex_key#21/1){+.+.}, at: do_unlinkat+0x3d8/0xa30 fs/namei.c:4049 2 locks held by syz-executor7/26965: #0: 000000001f1ead00 (sb_writers#19){.+.+}, at: sb_start_write include/linux/fs.h:1598 [inline] #0: 000000001f1ead00 (sb_writers#19){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 #1: 00000000e4e29039 (&sb->s_type->i_mutex_key#21/1){+.+.}, at: inode_lock_nested include/linux/fs.h:805 [inline] #1: 00000000e4e29039 (&sb->s_type->i_mutex_key#21/1){+.+.}, at: filename_create+0x1b2/0x5b0 fs/namei.c:3635 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 774 Comm: khungtaskd Not tainted 4.18.0-next-20180816+ #41 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+0x1c9/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.3+0x48/0x88 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x151/0x192 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:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0xb39/0x1040 kernel/hung_task.c:265 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:56