Eric Lee / smarc-ti-linux-kernel

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Commit 7efe8f1bb70588036edacab8b6c7f899092781f2

Authored by Eric Dumazet
Committed by Greg Kroah-Hartman
1 parent ab12ec41d8

tcp: fix more NULL deref after prequeue changes 

[ Upstream commit 0f85feae6b710ced3abad5b2b47d31dfcb956b62 ]

When I cooked commit c3658e8d0f1 ("tcp: fix possible NULL dereference in
tcp_vX_send_reset()") I missed other spots we could deref a NULL
skb_dst(skb)

Again, if a socket is provided, we do not need skb_dst() to get a
pointer to network namespace : sock_net(sk) is good enough.

Reported-by: Dann Frazier <dann.frazier@canonical.com>
Bisected-by: Dann Frazier <dann.frazier@canonical.com>
Tested-by: Dann Frazier <dann.frazier@canonical.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: ca777eff51f7 ("tcp: remove dst refcount false sharing for prequeue mode")
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Showing 2 changed files with 16 additions and 16 deletions Side-by-side Diff

... ... @@ -623,6 +623,7 @@
623 623 arg.iov[0].iov_base = (unsigned char *)&rep;
624 624 arg.iov[0].iov_len = sizeof(rep.th);
625 625  
  626 + net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
626 627 #ifdef CONFIG_TCP_MD5SIG
627 628 hash_location = tcp_parse_md5sig_option(th);
628 629 if (!sk && hash_location) {
... ... @@ -633,7 +634,7 @@
633 634 * Incoming packet is checked with md5 hash with finding key,
634 635 * no RST generated if md5 hash doesn't match.
635 636 */
636   - sk1 = __inet_lookup_listener(dev_net(skb_dst(skb)->dev),
  637 + sk1 = __inet_lookup_listener(net,
637 638 &tcp_hashinfo, ip_hdr(skb)->saddr,
638 639 th->source, ip_hdr(skb)->daddr,
639 640 ntohs(th->source), inet_iif(skb));
... ... @@ -681,7 +682,6 @@
681 682 if (sk)
682 683 arg.bound_dev_if = sk->sk_bound_dev_if;
683 684  
684   - net = dev_net(skb_dst(skb)->dev);
685 685 arg.tos = ip_hdr(skb)->tos;
686 686 ip_send_unicast_reply(net, skb, &TCP_SKB_CB(skb)->header.h4.opt,
687 687 ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
... ... @@ -787,16 +787,16 @@
787 787 .queue_hash_add = inet6_csk_reqsk_queue_hash_add,
788 788 };
789 789  
790   -static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
791   - u32 tsval, u32 tsecr, int oif,
792   - struct tcp_md5sig_key *key, int rst, u8 tclass,
793   - u32 label)
  790 +static void tcp_v6_send_response(struct sock *sk, struct sk_buff *skb, u32 seq,
  791 + u32 ack, u32 win, u32 tsval, u32 tsecr,
  792 + int oif, struct tcp_md5sig_key *key, int rst,
  793 + u8 tclass, u32 label)
794 794 {
795 795 const struct tcphdr *th = tcp_hdr(skb);
796 796 struct tcphdr *t1;
797 797 struct sk_buff *buff;
798 798 struct flowi6 fl6;
799   - struct net *net = dev_net(skb_dst(skb)->dev);
  799 + struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
800 800 struct sock *ctl_sk = net->ipv6.tcp_sk;
801 801 unsigned int tot_len = sizeof(struct tcphdr);
802 802 struct dst_entry *dst;
... ... @@ -946,7 +946,7 @@
946 946 (th->doff << 2);
947 947  
948 948 oif = sk ? sk->sk_bound_dev_if : 0;
949   - tcp_v6_send_response(skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
  949 + tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
950 950  
951 951 #ifdef CONFIG_TCP_MD5SIG
952 952 release_sk1:
953 953  
... ... @@ -957,13 +957,13 @@
957 957 #endif
958 958 }
959 959  
960   -static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
961   - u32 win, u32 tsval, u32 tsecr, int oif,
  960 +static void tcp_v6_send_ack(struct sock *sk, struct sk_buff *skb, u32 seq,
  961 + u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
962 962 struct tcp_md5sig_key *key, u8 tclass,
963 963 u32 label)
964 964 {
965   - tcp_v6_send_response(skb, seq, ack, win, tsval, tsecr, oif, key, 0, tclass,
966   - label);
  965 + tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
  966 + tclass, label);
967 967 }
968 968  
969 969 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
... ... @@ -971,7 +971,7 @@
971 971 struct inet_timewait_sock *tw = inet_twsk(sk);
972 972 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
973 973  
974   - tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
  974 + tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
975 975 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
976 976 tcp_time_stamp + tcptw->tw_ts_offset,
977 977 tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
978 978  
... ... @@ -986,10 +986,10 @@
986 986 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
987 987 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
988 988 */
989   - tcp_v6_send_ack(skb, (sk->sk_state == TCP_LISTEN) ?
  989 + tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
990 990 tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
991   - tcp_rsk(req)->rcv_nxt,
992   - req->rcv_wnd, tcp_time_stamp, req->ts_recent, sk->sk_bound_dev_if,
  991 + tcp_rsk(req)->rcv_nxt, req->rcv_wnd,
  992 + tcp_time_stamp, req->ts_recent, sk->sk_bound_dev_if,
993 993 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr),
994 994 0, 0);
995 995 }