INFO: task syz-executor3:14788 blocked for more than 140 seconds. Not tainted 4.19.0-rc5+ #34 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D23528 14788 5661 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473 schedule+0xfe/0x460 kernel/sched/core.c:3517 __rwsem_down_write_failed_common+0xbb9/0x1670 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+0xa9/0x130 kernel/locking/rwsem.c:194 inode_lock_nested include/linux/fs.h:773 [inline] lock_rename+0x236/0x290 fs/namei.c:2862 do_renameat2+0x696/0x1180 fs/namei.c:4577 __do_sys_rename fs/namei.c:4673 [inline] __se_sys_rename fs/namei.c:4671 [inline] __x64_sys_rename+0x5e/0x80 fs/namei.c:4671 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457579 Code: 24 08 48 89 01 e8 d7 2d fc ff e8 22 7a fc ff b8 02 00 00 00 48 8d 0d 2a 8a 08 01 87 01 8b 05 22 8a 08 01 83 f8 01 0f 85 8a 00 <00> 00 b8 01 00 00 00 88 05 5e 8f 08 01 84 c0 74 72 b8 01 00 00 00 RSP: 002b:00007f1a1a74bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000457579 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000020000040 RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1a1a74c6d4 R13: 00000000004c3295 R14: 00000000004d4e78 R15: 00000000ffffffff INFO: task syz-executor3:14789 blocked for more than 140 seconds. Not tainted 4.19.0-rc5+ #34 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D23816 14789 5661 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473 schedule+0xfe/0x460 kernel/sched/core.c:3517 __rwsem_down_write_failed_common+0xbb9/0x1670 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+0xa5/0x130 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:738 [inline] lock_mount+0x8c/0x2e0 fs/namespace.c:2027 do_add_mount+0x27/0x370 fs/namespace.c:2404 do_new_mount fs/namespace.c:2471 [inline] do_mount+0x19cd/0x31f0 fs/namespace.c:2787 ksys_mount+0x12d/0x140 fs/namespace.c:3003 __do_sys_mount fs/namespace.c:3017 [inline] __se_sys_mount fs/namespace.c:3014 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3014 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457579 Code: 24 08 48 89 01 e8 d7 2d fc ff e8 22 7a fc ff b8 02 00 00 00 48 8d 0d 2a 8a 08 01 87 01 8b 05 22 8a 08 01 83 f8 01 0f 85 8a 00 <00> 00 b8 01 00 00 00 88 05 5e 8f 08 01 84 c0 74 72 b8 01 00 00 00 RSP: 002b:00007f1a1a72ac78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000457579 RDX: 00000000200008c0 RSI: 0000000020000000 RDI: 0000000000000000 RBP: 000000000072c040 R08: 0000000020000a80 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1a1a72b6d4 R13: 00000000004c28b5 R14: 00000000004d3c90 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/986: #0: 00000000844d5946 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4435 1 lock held by rsyslogd/5432: #0: 00000000c339d46a (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5553: #0: 000000009f65ddc2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000dbcc4caf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5554: #0: 000000002d5a5ca6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000006c6424e9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5555: #0: 00000000e30f69e8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000bfc8b0d4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5556: #0: 00000000c46412e1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000c1b672d1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5557: #0: 000000000b63e426 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000c9ead274 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5558: #0: 000000006cc64b15 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000006874cd48 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5559: #0: 000000007d15e18c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000a998db30 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-executor3/14748: #0: 00000000d44c107b (sb_writers#14){.+.+}, at: sb_start_write include/linux/fs.h:1566 [inline] #0: 00000000d44c107b (sb_writers#14){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 #1: 000000007ceee704 (&sb->s_type->i_mutex_key#22/1){+.+.}, at: inode_lock_nested include/linux/fs.h:773 [inline] #1: 000000007ceee704 (&sb->s_type->i_mutex_key#22/1){+.+.}, at: lock_rename+0x236/0x290 fs/namei.c:2862 2 locks held by syz-executor3/14788: #0: 00000000d44c107b (sb_writers#14){.+.+}, at: sb_start_write include/linux/fs.h:1566 [inline] #0: 00000000d44c107b (sb_writers#14){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 #1: 000000007ceee704 (&sb->s_type->i_mutex_key#22/1){+.+.}, at: inode_lock_nested include/linux/fs.h:773 [inline] #1: 000000007ceee704 (&sb->s_type->i_mutex_key#22/1){+.+.}, at: lock_rename+0x236/0x290 fs/namei.c:2862 1 lock held by syz-executor3/14789: #0: 000000007ceee704 (&sb->s_type->i_mutex_key#22){++++}, at: inode_lock include/linux/fs.h:738 [inline] #0: 000000007ceee704 (&sb->s_type->i_mutex_key#22){++++}, at: lock_mount+0x8c/0x2e0 fs/namespace.c:2027 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 986 Comm: khungtaskd Not tainted 4.19.0-rc5+ #34 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+0x1c4/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.3+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x1ed 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+0xb3e/0x1050 kernel/hung_task.c:265 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 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:57