INFO: task syz-executor0:12637 blocked for more than 140 seconds. Not tainted 4.19.0+ #78 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D23304 12637 5531 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: 0033:0x457569 Code: 83 c4 18 c3 e8 d8 64 00 00 48 8b 04 24 48 8b 4c 24 08 48 89 01 e8 d7 2d fc ff e8 22 7a fc ff b8 02 00 00 00 48 8d 0d 2a 60 09 <01> 87 01 8b 05 22 60 09 01 83 f8 01 0f 85 8a 00 00 00 b8 01 00 00 RSP: 002b:00007fa28e684c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000457569 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000020000040 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa28e6856d4 R13: 00000000004c3281 R14: 00000000004d4e78 R15: 00000000ffffffff INFO: task syz-executor0:12669 blocked for more than 140 seconds. Not tainted 4.19.0+ #78 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D23816 12669 5531 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: 0033:0x457569 Code: 83 c4 18 c3 e8 d8 64 00 00 48 8b 04 24 48 8b 4c 24 08 48 89 01 e8 d7 2d fc ff e8 22 7a fc ff b8 02 00 00 00 48 8d 0d 2a 60 09 <01> 87 01 8b 05 22 60 09 01 83 f8 01 0f 85 8a 00 00 00 b8 01 00 00 RSP: 002b:00007fa28e642c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000457569 RDX: 00000000200008c0 RSI: 0000000020000000 RDI: 0000000000000000 RBP: 000000000072c040 R08: 0000000020000300 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa28e6436d4 R13: 00000000004c28a1 R14: 00000000004d3c90 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/983: #0: 00000000b3976ecb (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4435 1 lock held by rsyslogd/5366: 2 locks held by getty/5492: #0: 00000000a38299d9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000001a5f278b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5493: #0: 000000008d70d9a0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000087adc239 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5494: #0: 000000003f2d82cb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000011f1bddf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5495: #0: 0000000038f732b2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e455becc (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5496: #0: 00000000c83e04b5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e29244e7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5497: #0: 0000000065f08aee (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000009fadc64c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5498: #0: 00000000b7c97df1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e8eed09f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-executor0/12637: #0: 000000008056106c (sb_writers#14){.+.+}, at: sb_start_write include/linux/fs.h:1566 [inline] #0: 000000008056106c (sb_writers#14){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 #1: 000000002c7e9897 (&sb->s_type->i_mutex_key#20/1){+.+.}, at: inode_lock_nested include/linux/fs.h:773 [inline] #1: 000000002c7e9897 (&sb->s_type->i_mutex_key#20/1){+.+.}, at: lock_rename+0x236/0x290 fs/namei.c:2862 2 locks held by syz-executor0/12645: #0: 000000008056106c (sb_writers#14){.+.+}, at: sb_start_write include/linux/fs.h:1566 [inline] #0: 000000008056106c (sb_writers#14){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 #1: 000000002c7e9897 (&sb->s_type->i_mutex_key#20/1){+.+.}, at: inode_lock_nested include/linux/fs.h:773 [inline] #1: 000000002c7e9897 (&sb->s_type->i_mutex_key#20/1){+.+.}, at: lock_rename+0x236/0x290 fs/namei.c:2862 1 lock held by syz-executor0/12669: #0: 000000002c7e9897 (&sb->s_type->i_mutex_key#20){+.+.}, at: inode_lock include/linux/fs.h:738 [inline] #0: 000000002c7e9897 (&sb->s_type->i_mutex_key#20){+.+.}, at: lock_mount+0x8c/0x2e0 fs/namespace.c:2027 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 983 Comm: khungtaskd Not tainted 4.19.0+ #78 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+0x1c4/0x2b6 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 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57