INFO: task syz-executor.3:2606 can't die for more than 143 seconds. syz-executor.3 D29712 2606 8921 0x00000004 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x94a/0x1e70 kernel/sched/core.c:4070 schedule+0xdc/0x2b0 kernel/sched/core.c:4144 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:3630 user_path_create fs/namei.c:3688 [inline] do_mknodat fs/namei.c:3749 [inline] do_mknodat+0x1a4/0x480 fs/namei.c:3737 __do_sys_mknod fs/namei.c:3789 [inline] __se_sys_mknod fs/namei.c:3787 [inline] __x64_sys_mknod+0x7b/0xb0 fs/namei.c:3787 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a219 Code: 48 8d 7c 24 30 48 39 3b 75 ad 48 89 23 eb a8 cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 59 48 83 ec 48 48 89 6c 24 40 48 <8d> 6c 24 40 48 8b 59 20 48 85 db 75 49 48 8b 74 24 60 8b 4c 24 68 RSP: 002b:00007fca93c43c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a219 RDX: 0000000000000706 RSI: 000000000000c000 RDI: 00000000200004c0 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fca93c446d4 R13: 00000000004c6c08 R14: 00000000004dc340 R15: 00000000ffffffff INFO: task syz-executor.3:2606 blocked for more than 143 seconds. Not tainted 5.4.0-rc6-next-20191108 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D29712 2606 8921 0x00000004 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x94a/0x1e70 kernel/sched/core.c:4070 schedule+0xdc/0x2b0 kernel/sched/core.c:4144 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:3630 user_path_create fs/namei.c:3688 [inline] do_mknodat fs/namei.c:3749 [inline] do_mknodat+0x1a4/0x480 fs/namei.c:3737 __do_sys_mknod fs/namei.c:3789 [inline] __se_sys_mknod fs/namei.c:3787 [inline] __x64_sys_mknod+0x7b/0xb0 fs/namei.c:3787 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a219 Code: 48 8d 7c 24 30 48 39 3b 75 ad 48 89 23 eb a8 cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 59 48 83 ec 48 48 89 6c 24 40 48 <8d> 6c 24 40 48 8b 59 20 48 85 db 75 49 48 8b 74 24 60 8b 4c 24 68 RSP: 002b:00007fca93c43c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a219 RDX: 0000000000000706 RSI: 000000000000c000 RDI: 00000000200004c0 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fca93c446d4 R13: 00000000004c6c08 R14: 00000000004dc340 R15: 00000000ffffffff INFO: task syz-executor.3:2841 can't die for more than 143 seconds. syz-executor.3 D28184 2841 8921 0x00004004 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x94a/0x1e70 kernel/sched/core.c:4070 schedule+0xdc/0x2b0 kernel/sched/core.c:4144 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/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a219 Code: 48 8d 7c 24 30 48 39 3b 75 ad 48 89 23 eb a8 cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 59 48 83 ec 48 48 89 6c 24 40 48 <8d> 6c 24 40 48 8b 59 20 48 85 db 75 49 48 8b 74 24 60 8b 4c 24 68 RSP: 002b:00007fca93c22c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045a219 RDX: 0000000020000300 RSI: 0000000020000200 RDI: 0000000000000000 RBP: 000000000075c070 R08: 00000000200005c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fca93c236d4 R13: 00000000004c6d0d R14: 00000000004dc520 R15: 00000000ffffffff INFO: task syz-executor.3:2841 blocked for more than 144 seconds. Not tainted 5.4.0-rc6-next-20191108 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28184 2841 8921 0x00004004 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x94a/0x1e70 kernel/sched/core.c:4070 schedule+0xdc/0x2b0 kernel/sched/core.c:4144 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/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a219 Code: 48 8d 7c 24 30 48 39 3b 75 ad 48 89 23 eb a8 cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 59 48 83 ec 48 48 89 6c 24 40 48 <8d> 6c 24 40 48 8b 59 20 48 85 db 75 49 48 8b 74 24 60 8b 4c 24 68 RSP: 002b:00007fca93c22c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045a219 RDX: 0000000020000300 RSI: 0000000020000200 RDI: 0000000000000000 RBP: 000000000075c070 R08: 00000000200005c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fca93c236d4 R13: 00000000004c6d0d R14: 00000000004dc520 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1077: #0: ffffffff88fab880 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5336 1 lock held by rsyslogd/8786: #0: ffff8880a1490ae0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/8876: #0: ffff888090a04090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005eed2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8877: #0: ffff8880a5884090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f152e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8878: #0: ffff8880a7787090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f112e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8879: #0: ffff88809c755090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f192e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8880: #0: ffff888095945090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f0d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8881: #0: ffff8880a53bb090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f092e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8882: #0: ffff8880a47bd090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005ee12e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.3/2494: #0: ffff88805b6c0428 (sb_writers#12){.+.+}, at: sb_start_write include/linux/fs.h:1650 [inline] #0: ffff88805b6c0428 (sb_writers#12){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:354 #1: ffff88805192f890 (&sb->s_type->i_mutex_key#21/1){+.+.}, at: inode_lock_nested include/linux/fs.h:826 [inline] #1: ffff88805192f890 (&sb->s_type->i_mutex_key#21/1){+.+.}, at: filename_create+0x17c/0x4f0 fs/namei.c:3630 2 locks held by syz-executor.3/2606: #0: ffff88805b6c0428 (sb_writers#12){.+.+}, at: sb_start_write include/linux/fs.h:1650 [inline] #0: ffff88805b6c0428 (sb_writers#12){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:354 #1: ffff88805192f890 (&sb->s_type->i_mutex_key#21/1){+.+.}, at: inode_lock_nested include/linux/fs.h:826 [inline] #1: ffff88805192f890 (&sb->s_type->i_mutex_key#21/1){+.+.}, at: filename_create+0x17c/0x4f0 fs/namei.c:3630 1 lock held by syz-executor.3/2841: #0: ffff88805192f890 (&sb->s_type->i_mutex_key#22){+.+.}, at: inode_lock include/linux/fs.h:791 [inline] #0: ffff88805192f890 (&sb->s_type->i_mutex_key#22){+.+.}, at: lock_mount+0x8c/0x2e0 fs/namespace.c:2134 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1077 Comm: khungtaskd Not tainted 5.4.0-rc6-next-20191108 #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:269 [inline] watchdog+0xc8f/0x1350 kernel/hung_task.c:353 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