netlink: 2 bytes leftover after parsing attributes in process `syz-executor7'. ====================================================== WARNING: possible circular locking dependency detected 4.14.0-next-20171123+ #50 Not tainted ------------------------------------------------------ syz-executor0/5507 is trying to acquire lock: (console_lock){+.+.}, at: [] vcs_write+0x14d/0xca0 drivers/tty/vt/vc_screen.c:397 but task is already holding lock: (&pipe->mutex/1){+.+.}, at: [] pipe_lock_nested fs/pipe.c:67 [inline] (&pipe->mutex/1){+.+.}, at: [] pipe_lock+0x56/0x70 fs/pipe.c:75 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&pipe->mutex/1){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 pipe_lock_nested fs/pipe.c:67 [inline] pipe_lock+0x56/0x70 fs/pipe.c:75 iter_file_splice_write+0x264/0xf30 fs/splice.c:699 do_splice_from fs/splice.c:851 [inline] do_splice fs/splice.c:1147 [inline] SYSC_splice fs/splice.c:1402 [inline] SyS_splice+0x7d5/0x1630 fs/splice.c:1382 entry_SYSCALL_64_fastpath+0x1f/0x96 -> #2 (sb_writers){.+.+}: spin_lock include/linux/spinlock.h:315 [inline] fast_dput fs/dcache.c:688 [inline] dput.part.23+0x492/0x830 fs/dcache.c:795 -> #1 ((completion)&req.done){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 complete_acquire include/linux/completion.h:40 [inline] __wait_for_common kernel/sched/completion.c:109 [inline] wait_for_common kernel/sched/completion.c:123 [inline] wait_for_completion+0xcb/0x7b0 kernel/sched/completion.c:144 devtmpfs_create_node+0x32b/0x4a0 drivers/base/devtmpfs.c:115 device_add+0x120f/0x1640 drivers/base/core.c:1824 device_create_groups_vargs+0x1f3/0x250 drivers/base/core.c:2430 device_create_vargs drivers/base/core.c:2470 [inline] device_create+0xda/0x110 drivers/base/core.c:2506 vcs_make_sysfs+0x35/0x60 drivers/tty/vt/vc_screen.c:629 vc_allocate+0x4b7/0x6b0 drivers/tty/vt/vt.c:797 con_install+0x52/0x440 drivers/tty/vt/vt.c:2876 tty_driver_install_tty drivers/tty/tty_io.c:1215 [inline] tty_init_dev+0xf6/0x4a0 drivers/tty/tty_io.c:1315 tty_open_by_driver drivers/tty/tty_io.c:1942 [inline] tty_open+0x608/0xab0 drivers/tty/tty_io.c:1990 chrdev_open+0x257/0x730 fs/char_dev.c:417 do_dentry_open+0x682/0xd70 fs/open.c:752 vfs_open+0x107/0x230 fs/open.c:866 do_last fs/namei.c:3388 [inline] path_openat+0x1157/0x3530 fs/namei.c:3528 do_filp_open+0x25b/0x3b0 fs/namei.c:3563 do_sys_open+0x502/0x6d0 fs/open.c:1059 SYSC_open fs/open.c:1077 [inline] SyS_open+0x2d/0x40 fs/open.c:1072 entry_SYSCALL_64_fastpath+0x1f/0x96 -> #0 (console_lock){+.+.}: check_prevs_add kernel/locking/lockdep.c:2031 [inline] validate_chain kernel/locking/lockdep.c:2473 [inline] __lock_acquire+0x3498/0x47f0 kernel/locking/lockdep.c:3500 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 console_lock+0x4b/0x80 kernel/printk/printk.c:2047 vcs_write+0x14d/0xca0 drivers/tty/vt/vc_screen.c:397 __vfs_write+0xef/0x970 fs/read_write.c:480 __kernel_write+0xfe/0x350 fs/read_write.c:501 write_pipe_buf+0x175/0x220 fs/splice.c:797 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x328/0x730 fs/splice.c:626 splice_from_pipe+0x1e9/0x330 fs/splice.c:661 default_file_splice_write+0x40/0x90 fs/splice.c:809 do_splice_from fs/splice.c:851 [inline] do_splice fs/splice.c:1147 [inline] SYSC_splice fs/splice.c:1402 [inline] SyS_splice+0x7d5/0x1630 fs/splice.c:1382 entry_SYSCALL_64_fastpath+0x1f/0x96 other info that might help us debug this: Chain exists of: console_lock --> sb_writers --> &pipe->mutex/1 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&pipe->mutex/1); lock(sb_writers); lock(&pipe->mutex/1); lock(console_lock); *** DEADLOCK *** 1 lock held by syz-executor0/5507: #0: (&pipe->mutex/1){+.+.}, at: [] pipe_lock_nested fs/pipe.c:67 [inline] #0: (&pipe->mutex/1){+.+.}, at: [] pipe_lock+0x56/0x70 fs/pipe.c:75 stack backtrace: CPU: 0 PID: 5507 Comm: syz-executor0 Not tainted 4.14.0-next-20171123+ #50 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_circular_bug+0x42d/0x610 kernel/locking/lockdep.c:1271 check_prev_add+0x666/0x15f0 kernel/locking/lockdep.c:1914 check_prevs_add kernel/locking/lockdep.c:2031 [inline] validate_chain kernel/locking/lockdep.c:2473 [inline] __lock_acquire+0x3498/0x47f0 kernel/locking/lockdep.c:3500 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 console_lock+0x4b/0x80 kernel/printk/printk.c:2047 vcs_write+0x14d/0xca0 drivers/tty/vt/vc_screen.c:397 __vfs_write+0xef/0x970 fs/read_write.c:480 __kernel_write+0xfe/0x350 fs/read_write.c:501 write_pipe_buf+0x175/0x220 fs/splice.c:797 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x328/0x730 fs/splice.c:626 splice_from_pipe+0x1e9/0x330 fs/splice.c:661 default_file_splice_write+0x40/0x90 fs/splice.c:809 do_splice_from fs/splice.c:851 [inline] do_splice fs/splice.c:1147 [inline] SYSC_splice fs/splice.c:1402 [inline] SyS_splice+0x7d5/0x1630 fs/splice.c:1382 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x452879 RSP: 002b:00007ff5de452be8 EFLAGS: 00000212 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452879 RDX: 0000000000000013 RSI: 0000000000000000 RDI: 0000000000000014 RBP: 0000000000000086 R08: 00000000fffff5fc R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006eef90 R13: 0000000000000001 R14: 0000000000758078 R15: 0000000000000000 TCP: request_sock_TCP: Possible SYN flooding on port 20030. Sending cookies. Check SNMP counters. netlink: 2 bytes leftover after parsing attributes in process `syz-executor7'. netlink: 2 bytes leftover after parsing attributes in process `syz-executor7'. TCP: request_sock_TCP: Possible SYN flooding on port 20030. Sending cookies. Check SNMP counters. sock: sock_set_timeout: `syz-executor2' (pid 5629) tries to set negative timeout sock: sock_set_timeout: `syz-executor2' (pid 5608) tries to set negative timeout tmpfs: No value for mount option '‹¶K"WöËO¢©S£d€Yl®' tmpfs: No value for mount option '‹¶K"WöËO¢©S£d€Yl®' sock: sock_set_timeout: `syz-executor6' (pid 5743) tries to set negative timeout sock: sock_set_timeout: `syz-executor1' (pid 5744) tries to set negative timeout sock: sock_set_timeout: `syz-executor2' (pid 5747) tries to set negative timeout tmpfs: No value for mount option '‹¶K"WöËO¢©S£d€Yl®' sock: sock_set_timeout: `syz-executor2' (pid 5720) tries to set negative timeout sock: sock_set_timeout: `syz-executor6' (pid 5752) tries to set negative timeout sock: sock_set_timeout: `syz-executor1' (pid 5762) tries to set negative timeout dccp_invalid_packet: invalid packet type dccp_invalid_packet: invalid packet type nla_parse: 5 callbacks suppressed netlink: 3 bytes leftover after parsing attributes in process `syz-executor7'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor7'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor7'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor7'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor7'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor7'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor7'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor7'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor7'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor7'. sock: process `syz-executor0' is using obsolete setsockopt SO_BSDCOMPAT FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 1 CPU: 0 PID: 7940 Comm: syz-executor3 Not tainted 4.14.0-next-20171123+ #50 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 fail_dump lib/fault-inject.c:51 [inline] should_fail+0x8c0/0xa40 lib/fault-inject.c:149 should_failslab+0xec/0x120 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:425 [inline] slab_alloc_node mm/slab.c:3293 [inline] kmem_cache_alloc_node+0x56/0x760 mm/slab.c:3636 __alloc_skb+0xf1/0x780 net/core/skbuff.c:193 alloc_skb include/linux/skbuff.h:981 [inline] nlmsg_new include/net/netlink.h:511 [inline] inet_netconf_notify_devconf+0xb4/0x1d0 net/ipv4/devinet.c:1890 __devinet_sysctl_unregister.isra.24+0x87/0xb0 net/ipv4/devinet.c:2341 devinet_sysctl_unregister+0x92/0xf0 net/ipv4/devinet.c:2365 inetdev_destroy net/ipv4/devinet.c:310 [inline] inetdev_event+0xa02/0x1220 net/ipv4/devinet.c:1529 notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93 __raw_notifier_call_chain kernel/notifier.c:394 [inline] raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401 call_netdevice_notifiers_info+0x32/0x60 net/core/dev.c:1679 call_netdevice_notifiers net/core/dev.c:1697 [inline] rollback_registered_many+0x8ad/0xdf0 net/core/dev.c:7238 rollback_registered+0x1be/0x3c0 net/core/dev.c:7280 unregister_netdevice_queue+0x2e3/0x5d0 net/core/dev.c:8268 unregister_netdevice include/linux/netdevice.h:2462 [inline] __tun_detach+0x1177/0x1550 drivers/net/tun.c:658 tun_detach drivers/net/tun.c:669 [inline] tun_chr_close+0x44/0x60 drivers/net/tun.c:2845 __fput+0x333/0x7f0 fs/file_table.c:210 ____fput+0x15/0x20 fs/file_table.c:244 task_work_run+0x199/0x270 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x296/0x310 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264 entry_SYSCALL_64_fastpath+0x94/0x96 RIP: 0033:0x452879 RSP: 002b:00007fc523958be8 EFLAGS: 00000212 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000758020 RCX: 0000000000452879 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000013 RBP: 0000000000000048 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006ed760 R13: 0000000000000014 R14: 00007fc5239596d4 R15: ffffffffffffffff FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 1 PID: 8369 Comm: syz-executor7 Not tainted 4.14.0-next-20171123+ #50 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 fail_dump lib/fault-inject.c:51 [inline] should_fail+0x8c0/0xa40 lib/fault-inject.c:149 should_failslab+0xec/0x120 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:425 [inline] slab_alloc_node mm/slab.c:3293 [inline] kmem_cache_alloc_node+0x56/0x760 mm/slab.c:3636 __alloc_skb+0xf1/0x780 net/core/skbuff.c:193