====================================================== WARNING: possible circular locking dependency detected 4.15.0-rc9+ #218 Not tainted ------------------------------------------------------ syz-executor0/5573 is trying to acquire lock: (&xt[i].mutex){+.+.}, at: [<0000000032ff2c7e>] xt_find_target+0x44/0x1e0 net/netfilter/x_tables.c:229 but task is already holding lock: (sk_lock-AF_INET6){+.+.}, at: [<0000000072a3f9b6>] lock_sock include/net/sock.h:1463 [inline] (sk_lock-AF_INET6){+.+.}, at: [<0000000072a3f9b6>] ipv6_setsockopt+0xff/0x150 net/ipv6/ipv6_sockglue.c:927 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (sk_lock-AF_INET6){+.+.}: lock_sock_nested+0xc2/0x110 net/core/sock.c:2780 lock_sock include/net/sock.h:1463 [inline] do_ipv6_setsockopt.isra.8+0x3c5/0x39d0 net/ipv6/ipv6_sockglue.c:167 ipv6_setsockopt+0xd7/0x150 net/ipv6/ipv6_sockglue.c:922 dccp_setsockopt+0x85/0xd0 net/dccp/proto.c:576 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2978 SYSC_setsockopt net/socket.c:1849 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1828 entry_SYSCALL_64_fastpath+0x29/0xa0 -> #1 (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:659 __do_replace+0x79d/0xa50 net/ipv4/netfilter/ip_tables.c:1094 do_replace net/ipv4/netfilter/ip_tables.c:1150 [inline] do_ipt_set_ctl+0x40f/0x5f0 net/ipv4/netfilter/ip_tables.c:1680 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115 ip_setsockopt+0xa1/0xb0 net/ipv4/ip_sockglue.c:1260 sctp_setsockopt+0x2b6/0x61d0 net/sctp/socket.c:4141 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2978 SYSC_setsockopt net/socket.c:1849 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1828 entry_SYSCALL_64_fastpath+0x29/0xa0 -> #0 (&xt[i].mutex){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3914 __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_target+0x44/0x1e0 net/netfilter/x_tables.c:229 xt_request_find_target+0x2c/0xb0 net/netfilter/x_tables.c:255 find_check_entry.isra.7+0x669/0xcf0 net/ipv6/netfilter/ip6_tables.c:572 translate_table+0xf52/0x1690 net/ipv6/netfilter/ip6_tables.c:749 do_replace net/ipv6/netfilter/ip6_tables.c:1165 [inline] do_ip6t_set_ctl+0x370/0x5f0 net/ipv6/netfilter/ip6_tables.c:1691 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115 ipv6_setsockopt+0x115/0x150 net/ipv6/ipv6_sockglue.c:928 rawv6_setsockopt+0x4a/0xf0 net/ipv6/raw.c:1060 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2978 SYSC_setsockopt net/socket.c:1849 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1828 entry_SYSCALL_64_fastpath+0x29/0xa0 other info that might help us debug this: Chain exists of: &xt[i].mutex --> rtnl_mutex --> sk_lock-AF_INET6 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sk_lock-AF_INET6); lock(rtnl_mutex); lock(sk_lock-AF_INET6); lock(&xt[i].mutex); *** DEADLOCK *** 1 lock held by syz-executor0/5573: #0: (sk_lock-AF_INET6){+.+.}, at: [<0000000072a3f9b6>] lock_sock include/net/sock.h:1463 [inline] #0: (sk_lock-AF_INET6){+.+.}, at: [<0000000072a3f9b6>] ipv6_setsockopt+0xff/0x150 net/ipv6/ipv6_sockglue.c:927 stack backtrace: CPU: 0 PID: 5573 Comm: syz-executor0 Not tainted 4.15.0-rc9+ #218 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.37+0x2cd/0x2dc kernel/locking/lockdep.c:1218 check_prev_add kernel/locking/lockdep.c:1858 [inline] check_prevs_add kernel/locking/lockdep.c:1971 [inline] validate_chain kernel/locking/lockdep.c:2412 [inline] __lock_acquire+0x30a8/0x3e00 kernel/locking/lockdep.c:3426 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3914 __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_target+0x44/0x1e0 net/netfilter/x_tables.c:229 xt_request_find_target+0x2c/0xb0 net/netfilter/x_tables.c:255 find_check_entry.isra.7+0x669/0xcf0 net/ipv6/netfilter/ip6_tables.c:572 translate_table+0xf52/0x1690 net/ipv6/netfilter/ip6_tables.c:749 do_replace net/ipv6/netfilter/ip6_tables.c:1165 [inline] do_ip6t_set_ctl+0x370/0x5f0 net/ipv6/netfilter/ip6_tables.c:1691 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115 ipv6_setsockopt+0x115/0x150 net/ipv6/ipv6_sockglue.c:928 rawv6_setsockopt+0x4a/0xf0 net/ipv6/raw.c:1060 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2978 SYSC_setsockopt net/socket.c:1849 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1828 entry_SYSCALL_64_fastpath+0x29/0xa0 RIP: 0033:0x453299 RSP: 002b:00007f4145bffc58 EFLAGS: 00000212 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000453299 RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000013 RBP: 00000000000005ea R08: 00000000000004a0 R09: 0000000000000000 R10: 0000000020006a60 R11: 0000000000000212 R12: 00000000006f7e90 R13: 00000000ffffffff R14: 00007f4145c006d4 R15: 0000000000000000 audit: type=1400 audit(1517458074.363:20): avc: denied { create } for pid=5588 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_crypto_socket permissive=1 xt_SECMARK: invalid security context 'system_u:object_r:systemd_unit_file_t:s0:¯' audit: type=1400 audit(1517458074.390:21): avc: denied { setopt } for pid=5588 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_crypto_socket permissive=1 IPv4: Oversized IP packet from 127.0.0.1 xt_HL: TTL: invalid or unknown mode 3 TCP: request_sock_TCPv6: Possible SYN flooding on port 20014. Sending cookies. Check SNMP counters. xt_HL: TTL: invalid or unknown mode 3 syz-executor1 (5759) used greatest stack depth: 16224 bytes left TCP: request_sock_TCPv6: Possible SYN flooding on port 20014. Sending cookies. Check SNMP counters. Cannot find add_set index 0 as target Cannot find add_set index 0 as target netlink: 'syz-executor6': attribute type 13 has an invalid length. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=65 sclass=netlink_route_socket pig=5938 comm=syz-executor6 netlink: 'syz-executor6': attribute type 13 has an invalid length. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=65 sclass=netlink_route_socket pig=5969 comm=syz-executor6 syz-executor0 uses obsolete (PF_INET,SOCK_PACKET) xt_CT: netfilter: NOTRACK target is deprecated, use CT instead or upgrade iptables xt_CT: You must specify a L4 protocol, and not use inversions on it. xt_CT: You must specify a L4 protocol, and not use inversions on it. sctp: [Deprecated]: syz-executor7 (pid 6128) Use of int in maxseg socket option. Use struct sctp_assoc_value instead sctp: [Deprecated]: syz-executor7 (pid 6137) Use of int in maxseg socket option. Use struct sctp_assoc_value instead netlink: 'syz-executor1': attribute type 18 has an invalid length. netlink: 'syz-executor1': attribute type 18 has an invalid length. netlink: 3 bytes leftover after parsing attributes in process `syz-executor7'. sctp: [Deprecated]: syz-executor6 (pid 6298) Use of int in max_burst socket option deprecated. Use struct sctp_assoc_value instead sctp: [Deprecated]: syz-executor6 (pid 6307) Use of int in max_burst socket option deprecated. Use struct sctp_assoc_value instead sctp: [Deprecated]: syz-executor5 (pid 6321) Use of int in max_burst socket option deprecated. Use struct sctp_assoc_value instead sctp: [Deprecated]: syz-executor5 (pid 6349) Use of int in max_burst socket option deprecated. Use struct sctp_assoc_value instead netlink: 'syz-executor6': attribute type 16 has an invalid length. netlink: 'syz-executor6': attribute type 16 has an invalid length. xt_SECMARK: invalid security context 'system_u:objct_r:policy_src_t:s0' xt_SECMARK: invalid security context 'system_u:objct_r:policy_src_t:s0' netlink: 17 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 17 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor6'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor6'. Cannot find del_set index 0 as target Cannot find del_set index 0 as target openvswitch: netlink: Message has 4 unknown bytes. openvswitch: netlink: Message has 4 unknown bytes. netlink: 4 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 'syz-executor4': attribute type 1 has an invalid length. netlink: 4 bytes leftover after parsing attributes in process `syz-executor1'.