netlink: 20 bytes leftover after parsing attributes in process `syz-executor2'. INFO: task syz-executor7:12685 blocked for more than 140 seconds. Not tainted 4.18.0-rc7+ #173 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D24376 12685 4423 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_write_failed_common+0x95d/0x1630 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:750 [inline] do_unlinkat+0x3d8/0xa30 fs/namei.c:4059 __do_sys_unlink fs/namei.c:4120 [inline] __se_sys_unlink fs/namei.c:4118 [inline] __x64_sys_unlink+0x42/0x50 fs/namei.c:4118 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x456a09 Code: 24 00 00 00 e8 e8 4e fd ff 0f 0b e8 c1 34 00 00 e9 3c ff ff ff cc cc cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff <48> 3b 61 10 76 40 48 83 ec 28 48 89 6c 24 20 48 8d 6c 24 20 48 8b RSP: 002b:00007f62db12ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 00007f62db12f6d4 RCX: 0000000000456a09 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000300 RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d5c50 R14: 00000000004c6d06 R15: 0000000000000001 INFO: task syz-executor7:12686 blocked for more than 140 seconds. Not tainted 4.18.0-rc7+ #173 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D24088 12686 4423 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_write_failed_common+0x95d/0x1630 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+0xaa/0x130 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:715 [inline] lock_mount+0x8c/0x2e0 fs/namespace.c:2088 do_add_mount+0x27/0x370 fs/namespace.c:2465 do_new_mount fs/namespace.c:2532 [inline] do_mount+0x193f/0x30e0 fs/namespace.c:2848 ksys_mount+0x12d/0x140 fs/namespace.c:3064 __do_sys_mount fs/namespace.c:3078 [inline] __se_sys_mount fs/namespace.c:3075 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3075 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x456a09 Code: 24 00 00 00 e8 e8 4e fd ff 0f 0b e8 c1 34 00 00 e9 3c ff ff ff cc cc cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff <48> 3b 61 10 76 40 48 83 ec 28 48 89 6c 24 20 48 8d 6c 24 20 48 8b RSP: 002b:00007f62db10dc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f62db10e6d4 RCX: 0000000000456a09 RDX: 0000000020000900 RSI: 0000000020000000 RDI: 0000000000000000 RBP: 00000000009301e0 R08: 0000000020000380 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d1750 R14: 00000000004c6e7f R15: 0000000000000002 Showing all locks held in the system: 1 lock held by khungtaskd/773: #0: 000000006aceec17 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461 1 lock held by rsyslogd/4279: #0: 00000000a044d6b1 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/4369: #0: 0000000044e98459 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000162f35e1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4370: #0: 000000009f17360e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000616b4485 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4371: #0: 00000000b7e51ef3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000041ff0ce1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4372: #0: 00000000473312ca (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000ddc55e0c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4373: #0: 0000000028956fc7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000053db6c0c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4374: #0: 00000000d96466d3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000002961f12a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4375: #0: 00000000854f0557 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000c901aa54 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-executor7/12600: #0: 00000000ecf076f2 (sb_writers#20){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000ecf076f2 (sb_writers#20){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 000000006a371dc2 (&sb->s_type->i_mutex_key#22/1){+.+.}, at: inode_lock_nested include/linux/fs.h:750 [inline] #1: 000000006a371dc2 (&sb->s_type->i_mutex_key#22/1){+.+.}, at: do_unlinkat+0x3d8/0xa30 fs/namei.c:4059 2 locks held by syz-executor7/12685: #0: 00000000ecf076f2 (sb_writers#20){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000ecf076f2 (sb_writers#20){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 000000006a371dc2 (&sb->s_type->i_mutex_key#22/1){+.+.}, at: inode_lock_nested include/linux/fs.h:750 [inline] #1: 000000006a371dc2 (&sb->s_type->i_mutex_key#22/1){+.+.}, at: do_unlinkat+0x3d8/0xa30 fs/namei.c:4059 1 lock held by syz-executor7/12686: #0: 000000006a371dc2 (&sb->s_type->i_mutex_key#24){+.+.}, at: inode_lock include/linux/fs.h:715 [inline] #0: 000000006a371dc2 (&sb->s_type->i_mutex_key#24){+.+.}, at: lock_mount+0x8c/0x2e0 fs/namespace.c:2088 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 773 Comm: khungtaskd Not tainted 4.18.0-rc7+ #173 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.4+0x19/0xce lib/nmi_backtrace.c:103 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:138 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline] watchdog+0x9c4/0xf80 kernel/hung_task.c:252 kthread+0x345/0x410 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 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:54