INFO: task syz-executor.1:24714 can't die for more than 143 seconds. syz-executor.1 D28520 24714 9100 0x00000004 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4081 schedule+0xdc/0x2b0 kernel/sched/core.c:4155 rwsem_down_write_slowpath+0x706/0xf80 kernel/locking/rwsem.c:1238 __down_write kernel/locking/rwsem.c:1392 [inline] down_write_nested+0x140/0x160 kernel/locking/rwsem.c:1631 inode_lock_nested include/linux/fs.h:826 [inline] filename_create+0x17c/0x4f0 fs/namei.c:3638 user_path_create fs/namei.c:3696 [inline] do_mknodat fs/namei.c:3757 [inline] do_mknodat+0x1a4/0x480 fs/namei.c:3745 __do_sys_mknod fs/namei.c:3797 [inline] __se_sys_mknod fs/namei.c:3795 [inline] __x64_sys_mknod+0x7b/0xb0 fs/namei.c:3795 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a679 Code: f3 a4 48 8b 94 24 18 10 00 00 ff 12 48 8b 94 24 10 10 00 00 48 8b bc 24 20 10 00 00 8b 8c 24 28 10 00 00 8b 9c 24 2c 10 00 00 <48> 89 e6 48 01 df 48 01 de 48 29 d9 e8 c6 fa ff ff 48 8b ac 24 00 RSP: 002b:00007f9b548fec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a679 RDX: 0000000000000702 RSI: 0000000000000000 RDI: 00000000200004c0 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9b548ff6d4 R13: 00000000004c7838 R14: 00000000004de530 R15: 00000000ffffffff INFO: task syz-executor.1:24714 blocked for more than 143 seconds. Not tainted 5.4.0-next-20191205-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28520 24714 9100 0x00000004 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4081 schedule+0xdc/0x2b0 kernel/sched/core.c:4155 rwsem_down_write_slowpath+0x706/0xf80 kernel/locking/rwsem.c:1238 __down_write kernel/locking/rwsem.c:1392 [inline] down_write_nested+0x140/0x160 kernel/locking/rwsem.c:1631 inode_lock_nested include/linux/fs.h:826 [inline] filename_create+0x17c/0x4f0 fs/namei.c:3638 user_path_create fs/namei.c:3696 [inline] do_mknodat fs/namei.c:3757 [inline] do_mknodat+0x1a4/0x480 fs/namei.c:3745 __do_sys_mknod fs/namei.c:3797 [inline] __se_sys_mknod fs/namei.c:3795 [inline] __x64_sys_mknod+0x7b/0xb0 fs/namei.c:3795 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a679 Code: f3 a4 48 8b 94 24 18 10 00 00 ff 12 48 8b 94 24 10 10 00 00 48 8b bc 24 20 10 00 00 8b 8c 24 28 10 00 00 8b 9c 24 2c 10 00 00 <48> 89 e6 48 01 df 48 01 de 48 29 d9 e8 c6 fa ff ff 48 8b ac 24 00 RSP: 002b:00007f9b548fec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a679 RDX: 0000000000000702 RSI: 0000000000000000 RDI: 00000000200004c0 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9b548ff6d4 R13: 00000000004c7838 R14: 00000000004de530 R15: 00000000ffffffff INFO: task syz-executor.1:24715 can't die for more than 143 seconds. syz-executor.1 D28184 24715 9100 0x00004004 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4081 schedule+0xdc/0x2b0 kernel/sched/core.c:4155 rwsem_down_write_slowpath+0x706/0xf80 kernel/locking/rwsem.c:1238 __down_write kernel/locking/rwsem.c:1392 [inline] down_write+0x13c/0x150 kernel/locking/rwsem.c:1535 inode_lock include/linux/fs.h:791 [inline] lock_mount+0x8c/0x2e0 fs/namespace.c:2134 do_add_mount+0x27/0x380 fs/namespace.c:2708 do_new_mount_fc fs/namespace.c:2771 [inline] do_new_mount fs/namespace.c:2824 [inline] do_mount+0x1701/0x1b50 fs/namespace.c:3142 ksys_mount+0xdb/0x150 fs/namespace.c:3351 __do_sys_mount fs/namespace.c:3365 [inline] __se_sys_mount fs/namespace.c:3362 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3362 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a679 Code: f3 a4 48 8b 94 24 18 10 00 00 ff 12 48 8b 94 24 10 10 00 00 48 8b bc 24 20 10 00 00 8b 8c 24 28 10 00 00 8b 9c 24 2c 10 00 00 <48> 89 e6 48 01 df 48 01 de 48 29 d9 e8 c6 fa ff ff 48 8b ac 24 00 RSP: 002b:00007f9b548ddc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045a679 RDX: 0000000020000300 RSI: 0000000020000200 RDI: 0000000000000000 RBP: 000000000075c070 R08: 00000000200005c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9b548de6d4 R13: 00000000004c7981 R14: 00000000004de788 R15: 00000000ffffffff INFO: task syz-executor.1:24715 blocked for more than 144 seconds. Not tainted 5.4.0-next-20191205-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28184 24715 9100 0x00004004 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4081 schedule+0xdc/0x2b0 kernel/sched/core.c:4155 rwsem_down_write_slowpath+0x706/0xf80 kernel/locking/rwsem.c:1238 __down_write kernel/locking/rwsem.c:1392 [inline] down_write+0x13c/0x150 kernel/locking/rwsem.c:1535 inode_lock include/linux/fs.h:791 [inline] lock_mount+0x8c/0x2e0 fs/namespace.c:2134 do_add_mount+0x27/0x380 fs/namespace.c:2708 do_new_mount_fc fs/namespace.c:2771 [inline] do_new_mount fs/namespace.c:2824 [inline] do_mount+0x1701/0x1b50 fs/namespace.c:3142 ksys_mount+0xdb/0x150 fs/namespace.c:3351 __do_sys_mount fs/namespace.c:3365 [inline] __se_sys_mount fs/namespace.c:3362 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3362 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a679 Code: f3 a4 48 8b 94 24 18 10 00 00 ff 12 48 8b 94 24 10 10 00 00 48 8b bc 24 20 10 00 00 8b 8c 24 28 10 00 00 8b 9c 24 2c 10 00 00 <48> 89 e6 48 01 df 48 01 de 48 29 d9 e8 c6 fa ff ff 48 8b ac 24 00 RSP: 002b:00007f9b548ddc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045a679 RDX: 0000000020000300 RSI: 0000000020000200 RDI: 0000000000000000 RBP: 000000000075c070 R08: 00000000200005c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9b548de6d4 R13: 00000000004c7981 R14: 00000000004de788 R15: 00000000ffffffff Showing all locks held in the system: 3 locks held by kworker/u4:0/7: #0: ffff8880ae937358 (&rq->lock){-.-.}, at: newidle_balance+0xa28/0xe80 kernel/sched/fair.c:10166 #1: ffffffff899ae4c0 (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:5729 #2: ffff8880ae927258 (&base->lock){-.-.}, at: lock_timer_base+0x56/0x1b0 kernel/time/timer.c:936 1 lock held by khungtaskd/1122: #0: ffffffff899ae4c0 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5334 2 locks held by getty/9056: #0: ffff88809169c090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000171b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9057: #0: ffff888095efb090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000172b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9058: #0: ffff8880a4905090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900017ab2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9059: #0: ffff88809edd8090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000177b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9060: #0: ffff8880a7d42090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000178b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9061: #0: ffff88809569f090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000179b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9062: #0: ffff8880a0e9a090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900016f32e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.1/24687: #0: ffff8880a8efe428 (sb_writers#13){.+.+}, at: sb_start_write include/linux/fs.h:1650 [inline] #0: ffff8880a8efe428 (sb_writers#13){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:354 #1: ffff888093b55728 (&sb->s_type->i_mutex_key#21/1){+.+.}, at: inode_lock_nested include/linux/fs.h:826 [inline] #1: ffff888093b55728 (&sb->s_type->i_mutex_key#21/1){+.+.}, at: filename_create+0x17c/0x4f0 fs/namei.c:3638 2 locks held by syz-executor.1/24714: #0: ffff8880a8efe428 (sb_writers#13){.+.+}, at: sb_start_write include/linux/fs.h:1650 [inline] #0: ffff8880a8efe428 (sb_writers#13){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:354 #1: ffff888093b55728 (&sb->s_type->i_mutex_key#21/1){+.+.}, at: inode_lock_nested include/linux/fs.h:826 [inline] #1: ffff888093b55728 (&sb->s_type->i_mutex_key#21/1){+.+.}, at: filename_create+0x17c/0x4f0 fs/namei.c:3638 1 lock held by syz-executor.1/24715: #0: ffff888093b55728 (&sb->s_type->i_mutex_key#22){++++}, at: inode_lock include/linux/fs.h:791 [inline] #0: ffff888093b55728 (&sb->s_type->i_mutex_key#22){++++}, at: lock_mount+0x8c/0x2e0 fs/namespace.c:2134 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1122 Comm: khungtaskd Not tainted 5.4.0-next-20191205-syzkaller #0 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+0x197/0x210 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b 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:249 [inline] watchdog+0xdf1/0x14e0 kernel/hung_task.c:333 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60