aboutsummaryrefslogtreecommitdiff
path: root/net
diff options
context:
space:
mode:
authorMichal Kubeček <mkubecek@suse.cz>2015-03-23 15:14:00 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-04-29 10:33:54 +0200
commit1b946e381d185db8700e96634074052a62a11509 (patch)
tree79af1f116ec563af9f2dd65d5fd15e062b74ebad /net
parent1554b19c4080476e4e5b678febd5fc7f2d102322 (diff)
downloadlinux-linaro-stable-1b946e381d185db8700e96634074052a62a11509.tar.gz
tcp: prevent fetching dst twice in early demux code
[ Upstream commit d0c294c53a771ae7e84506dfbd8c18c30f078735 ] On s390x, gcc 4.8 compiles this part of tcp_v6_early_demux() struct dst_entry *dst = sk->sk_rx_dst; if (dst) dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie); to code reading sk->sk_rx_dst twice, once for the test and once for the argument of ip6_dst_check() (dst_check() is inline). This allows ip6_dst_check() to be called with null first argument, causing a crash. Protect sk->sk_rx_dst access by ACCESS_ONCE() both in IPv4 and IPv6 TCP early demux code. Fixes: 41063e9dd119 ("ipv4: Early TCP socket demux.") Fixes: c7109986db3c ("ipv6: Early TCP socket demux") Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/tcp_ipv4.c2
-rw-r--r--net/ipv6/tcp_ipv6.c2
2 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index cce35e5a7ee6..7c3eec386a4b 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1901,7 +1901,7 @@ void tcp_v4_early_demux(struct sk_buff *skb)
skb->sk = sk;
skb->destructor = sock_edemux;
if (sk->sk_state != TCP_TIME_WAIT) {
- struct dst_entry *dst = sk->sk_rx_dst;
+ struct dst_entry *dst = ACCESS_ONCE(sk->sk_rx_dst);
if (dst)
dst = dst_check(dst, 0);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 1a87659a6139..4659b8ab55d9 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1616,7 +1616,7 @@ static void tcp_v6_early_demux(struct sk_buff *skb)
skb->sk = sk;
skb->destructor = sock_edemux;
if (sk->sk_state != TCP_TIME_WAIT) {
- struct dst_entry *dst = sk->sk_rx_dst;
+ struct dst_entry *dst = ACCESS_ONCE(sk->sk_rx_dst);
if (dst)
dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);