====================================================== WARNING: possible circular locking dependency detected capability: warning: `syz-executor0' uses deprecated v2 capabilities in a way that may be insecure 4.16.0-rc1+ #315 Not tainted ------------------------------------------------------ syz-executor3/6109 is trying to acquire lock: (sk_lock-AF_INET6){+.+.}, at: [<000000005d023aae>] lock_sock include/net/sock.h:1463 [inline] (sk_lock-AF_INET6){+.+.}, at: [<000000005d023aae>] do_ipv6_setsockopt.isra.8+0x3a8/0x39d0 net/ipv6/ipv6_sockglue.c:167 but task is already holding lock: (rtnl_mutex){+.+.}, at: [<00000000fef02c1d>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (rtnl_mutex){+.+.}: __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 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 unregister_netdevice_notifier+0x91/0x4e0 net/core/dev.c:1673 tee_tg_destroy+0x61/0xc0 net/netfilter/xt_TEE.c:123 cleanup_entry+0x218/0x350 net/ipv4/netfilter/ip_tables.c:654 __do_replace+0x79d/0xa50 net/ipv4/netfilter/ip_tables.c:1089 do_replace net/ipv4/netfilter/ip_tables.c:1145 [inline] do_ipt_set_ctl+0x40f/0x5f0 net/ipv4/netfilter/ip_tables.c:1675 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115 ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1259 tcp_setsockopt+0x82/0xd0 net/ipv4/tcp.c:2905 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975 SYSC_setsockopt net/socket.c:1849 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1828 do_syscall_64+0x280/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #1 (&xt[i].mutex){+.+.}: __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 xt_find_table_lock+0x3e/0x3e0 net/netfilter/x_tables.c:1046 xt_request_find_table_lock+0x28/0xc0 net/netfilter/x_tables.c:1093 get_info+0x154/0x690 net/ipv6/netfilter/ip6_tables.c:989 do_ip6t_get_ctl+0x159/0xaf0 net/ipv6/netfilter/ip6_tables.c:1710 nf_sockopt net/netfilter/nf_sockopt.c:104 [inline] nf_getsockopt+0x6a/0xc0 net/netfilter/nf_sockopt.c:122 ipv6_getsockopt+0x1df/0x2e0 net/ipv6/ipv6_sockglue.c:1371 tcp_getsockopt+0x82/0xd0 net/ipv4/tcp.c:3359 sock_common_getsockopt+0x95/0xd0 net/core/sock.c:2934 SYSC_getsockopt net/socket.c:1880 [inline] SyS_getsockopt+0x178/0x340 net/socket.c:1862 do_syscall_64+0x280/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #0 (sk_lock-AF_INET6){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920 lock_sock_nested+0xc2/0x110 net/core/sock.c:2777 lock_sock include/net/sock.h:1463 [inline] do_ipv6_setsockopt.isra.8+0x3a8/0x39d0 net/ipv6/ipv6_sockglue.c:167 ipv6_setsockopt+0xd7/0x130 net/ipv6/ipv6_sockglue.c:922 udpv6_setsockopt+0x45/0x80 net/ipv6/udp.c:1422 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975 SYSC_setsockopt net/socket.c:1849 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1828 do_syscall_64+0x280/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 other info that might help us debug this: Chain exists of: sk_lock-AF_INET6 --> &xt[i].mutex --> rtnl_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(rtnl_mutex); lock(&xt[i].mutex); lock(rtnl_mutex); lock(sk_lock-AF_INET6); *** DEADLOCK *** 1 lock held by syz-executor3/6109: #0: (rtnl_mutex){+.+.}, at: [<00000000fef02c1d>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 stack backtrace: CPU: 0 PID: 6109 Comm: syz-executor3 Not tainted 4.16.0-rc1+ #315 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.isra.38+0x2cd/0x2dc kernel/locking/lockdep.c:1223 check_prev_add kernel/locking/lockdep.c:1863 [inline] check_prevs_add kernel/locking/lockdep.c:1976 [inline] validate_chain kernel/locking/lockdep.c:2417 [inline] __lock_acquire+0x30a8/0x3e00 kernel/locking/lockdep.c:3431 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920 lock_sock_nested+0xc2/0x110 net/core/sock.c:2777 lock_sock include/net/sock.h:1463 [inline] do_ipv6_setsockopt.isra.8+0x3a8/0x39d0 net/ipv6/ipv6_sockglue.c:167 ipv6_setsockopt+0xd7/0x130 net/ipv6/ipv6_sockglue.c:922 udpv6_setsockopt+0x45/0x80 net/ipv6/udp.c:1422 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975 SYSC_setsockopt net/socket.c:1849 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1828 do_syscall_64+0x280/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x453a59 RSP: 002b:00007f3d9f291c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f3d9f2926d4 RCX: 0000000000453a59 RDX: 0000000000000001 RSI: 0000000000000029 RDI: 0000000000000013 RBP: 000000000071bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000005ab R14: 00000000006f88a8 R15: 0000000000000000 IPVS: ftp: loaded support on port[0] = 21 IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready mac80211_hwsim: wmediumd released netlink socket, switching to perfect channel medium kauditd_printk_skb: 27 callbacks suppressed audit: type=1400 audit(1518822276.335:54): avc: denied { setopt } for pid=6496 comm="syz-executor3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1518822276.336:55): avc: denied { net_broadcast } for pid=6496 comm="syz-executor3" capability=11 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 futex_wake_op: syz-executor4 tries to shift op by -1; fix this program futex_wake_op: syz-executor4 tries to shift op by -1; fix this program TCP: request_sock_TCPv6: Possible SYN flooding on port 20026. Sending cookies. Check SNMP counters. audit: type=1400 audit(1518822276.779:56): avc: denied { setattr } for pid=6588 comm="syz-executor4" name="NETLINK" dev="sockfs" ino=17657 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1518822276.934:57): avc: denied { set_context_mgr } for pid=6618 comm="syz-executor3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=binder permissive=1 binder: 6618:6631 tried to acquire reference to desc 0, got 1 instead audit: type=1400 audit(1518822276.977:58): avc: denied { setuid } for pid=6614 comm="syz-executor5" capability=7 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 dst_release: dst:00000000431ce294 refcnt:-1 TCP: request_sock_TCPv6: Possible SYN flooding on port 20010. Sending cookies. Check SNMP counters. audit: type=1400 audit(1518822277.353:59): avc: denied { setfcap } for pid=6737 comm="syz-executor6" capability=31 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 Dead loop on virtual device ip6_vti0, fix it urgently! audit: type=1400 audit(1518822277.639:60): avc: denied { bind } for pid=6818 comm="syz-executor4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1518822277.639:61): avc: denied { setpcap } for pid=6827 comm="syz-executor7" capability=8 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 audit: type=1400 audit(1518822277.805:62): avc: denied { map } for pid=6870 comm="syz-executor6" path="pipe:[18043]" dev="pipefs" ino=18043 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=fifo_file permissive=1