From: Eric Dumazet Date: Tue, 9 Dec 2014 17:56:08 +0000 (-0800) Subject: tcp: fix more NULL deref after prequeue changes X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=04140b07839b75932f4a5f2bdb51a7c57f6b7c93;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git tcp: fix more NULL deref after prequeue changes 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. [Backport of net-next 0f85feae6b710ced3abad5b2b47d31dfcb956b62] Bug: 16355602 Change-Id: I72c9f7dae8da4451112a20ea36183365303bd389 Reported-by: Dann Frazier Bisected-by: Dann Frazier Tested-by: Dann Frazier Signed-off-by: Eric Dumazet Fixes: ca777eff51f7 ("tcp: remove dst refcount false sharing for prequeue mode") Signed-off-by: David S. Miller --- diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 4c61ec553be..58e2947cf5e 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -651,6 +651,7 @@ static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb) arg.iov[0].iov_base = (unsigned char *)&rep; arg.iov[0].iov_len = sizeof(rep.th); + net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev); #ifdef CONFIG_TCP_MD5SIG hash_location = tcp_parse_md5sig_option(th); if (!sk && hash_location) { @@ -661,7 +662,7 @@ static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb) * Incoming packet is checked with md5 hash with finding key, * no RST generated if md5 hash doesn't match. */ - sk1 = __inet_lookup_listener(dev_net(skb_dst(skb)->dev), + sk1 = __inet_lookup_listener(net, &tcp_hashinfo, ip_hdr(skb)->saddr, th->source, ip_hdr(skb)->daddr, ntohs(th->source), inet_iif(skb)); @@ -709,7 +710,6 @@ static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb) if (sk) arg.bound_dev_if = sk->sk_bound_dev_if; - net = dev_net(skb_dst(skb)->dev); arg.tos = ip_hdr(skb)->tos; ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk), skb, ip_hdr(skb)->saddr, diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 285cd599393..15cd50d3cce 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -723,15 +723,15 @@ static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = { }; #endif -static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win, - u32 tsval, u32 tsecr, +static void tcp_v6_send_response(struct sock *sk, struct sk_buff *skb, u32 seq, + u32 ack, u32 win, u32 tsval, u32 tsecr, struct tcp_md5sig_key *key, int rst, u8 tclass) { const struct tcphdr *th = tcp_hdr(skb); struct tcphdr *t1; struct sk_buff *buff; struct flowi6 fl6; - struct net *net = dev_net(skb_dst(skb)->dev); + struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev); struct sock *ctl_sk = net->ipv6.tcp_sk; unsigned int tot_len = sizeof(struct tcphdr); struct dst_entry *dst; @@ -873,7 +873,7 @@ static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb) ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len - (th->doff << 2); - tcp_v6_send_response(skb, seq, ack_seq, 0, 0, 0, key, 1, 0); + tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, key, 1, 0); #ifdef CONFIG_TCP_MD5SIG release_sk1: @@ -884,11 +884,12 @@ release_sk1: #endif } -static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, - u32 win, u32 tsval, u32 tsecr, +static void tcp_v6_send_ack(struct sock *sk, struct sk_buff *skb, + u32 seq, u32 ack, u32 win, u32 tsval, u32 tsecr, struct tcp_md5sig_key *key, u8 tclass) { - tcp_v6_send_response(skb, seq, ack, win, tsval, tsecr, key, 0, tclass); + tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, key, 0, + tclass); } static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb) @@ -896,7 +897,7 @@ static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb) struct inet_timewait_sock *tw = inet_twsk(sk); struct tcp_timewait_sock *tcptw = tcp_twsk(sk); - tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, + tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, tcp_time_stamp + tcptw->tw_ts_offset, tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw), @@ -913,7 +914,7 @@ static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb, * exception of segments, MUST be right-shifted by * Rcv.Wind.Shift bits: */ - tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, + tcp_v6_send_ack(sk, skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd >> inet_rsk(req)->rcv_wscale, tcp_time_stamp, req->ts_recent, tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr), 0);