====================================================== WARNING: possible circular locking dependency detected 4.15.0+ #288 Not tainted ------------------------------------------------------ syzkaller537783/4161 is trying to acquire lock: (rtnl_mutex){+.+.}, at: [<000000006ad06b3d>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 but task is already holding lock: (&xt[i].mutex){+.+.}, at: [<00000000a465a133>] xt_find_table_lock+0x40/0x3d0 net/netfilter/x_tables.c:1036 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&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_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:567 translate_table+0xf52/0x1690 net/ipv6/netfilter/ip6_tables.c:744 do_replace net/ipv6/netfilter/ip6_tables.c:1162 [inline] do_ip6t_set_ctl+0x370/0x5f0 net/ipv6/netfilter/ip6_tables.c:1688 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:2968 SYSC_setsockopt net/socket.c:1831 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1810 entry_SYSCALL_64_fastpath+0x29/0xa0 -> #1 (sk_lock-AF_INET6){+.+.}: lock_sock_nested+0xc2/0x110 net/core/sock.c:2770 lock_sock include/net/sock.h:1459 [inline] do_ipv6_setsockopt.isra.8+0x3c5/0x39d0 net/ipv6/ipv6_sockglue.c:167 ipv6_setsockopt+0xd7/0x150 net/ipv6/ipv6_sockglue.c:922 udpv6_setsockopt+0x45/0x80 net/ipv6/udp.c:1452 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2968 SYSC_setsockopt net/socket.c:1831 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1810 entry_SYSCALL_64_fastpath+0x29/0xa0 -> #0 (rtnl_mutex){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920 __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:72 unregister_netdevice_notifier+0x91/0x4e0 net/core/dev.c:1656 tee_tg_destroy+0x61/0xc0 net/netfilter/xt_TEE.c:123 cleanup_entry+0x218/0x350 net/ipv4/netfilter/ip_tables.c:654 __do_replace+0x7d7/0xa90 net/ipv4/netfilter/ip_tables.c:1091 do_replace net/ipv4/netfilter/ip_tables.c:1147 [inline] do_ipt_set_ctl+0x40f/0x5f0 net/ipv4/netfilter/ip_tables.c:1677 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:1256 sctp_setsockopt+0x2a0/0x5de0 net/sctp/socket.c:4074 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2968 SYSC_setsockopt net/socket.c:1831 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1810 entry_SYSCALL_64_fastpath+0x29/0xa0 other info that might help us debug this: Chain exists of: rtnl_mutex --> sk_lock-AF_INET6 --> &xt[i].mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&xt[i].mutex); lock(sk_lock-AF_INET6); lock(&xt[i].mutex); lock(rtnl_mutex); *** DEADLOCK *** 2 locks held by syzkaller537783/4161: #0: (sk_lock-AF_INET){+.+.}, at: [<0000000031464a2f>] lock_sock include/net/sock.h:1459 [inline] #0: (sk_lock-AF_INET){+.+.}, at: [<0000000031464a2f>] ip_setsockopt+0x8c/0xb0 net/ipv4/ip_sockglue.c:1255 #1: (&xt[i].mutex){+.+.}, at: [<00000000a465a133>] xt_find_table_lock+0x40/0x3d0 net/netfilter/x_tables.c:1036 stack backtrace: CPU: 0 PID: 4161 Comm: syzkaller537783 Not tainted 4.15.0+ #288 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 __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:72 unregister_netdevice_notifier+0x91/0x4e0 net/core/dev.c:1656 tee_tg_destroy+0x61/0xc0 net/netfilter/xt_TEE.c:123 cleanup_entry+0x218/0x350 net/ipv4/netfilter/ip_tables.c:654 __do_replace+0x7d7/0xa90 net/ipv4/netfilter/ip_tables.c:1091 do_replace net/ipv4/netfilter/ip_tables.c:1147 [inline] do_ipt_set_ctl+0x40f/0x5f0 net/ipv4/netfilter/ip_tables.c:1677 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:1256 sctp_setsockopt+0x2a0/0x5de0 net/sctp/socket.c:4074 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2968 SYSC_setsockopt net/socket.c:1831 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1810 entry_SYSCALL_64_fastpath+0x29/0xa0 RIP: 0033:0x442189 RSP: 002b:00007fff15b73848 EFLAGS: 00000207 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000442189 RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000007 RBP: 00000000006cc018 R08: 0000000000000308 R09: 0000000000000000 R10: 000000002002ccf8 R11: 0000000000000207 R12: 0000000000403ab0 R13: 0000000000403b40 R14: 0000000000000000 R15: 0000000000000000