diff options
| author | Eric Dumazet <edumazet@google.com> | 2018-09-30 11:33:39 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-10-20 09:52:36 +0200 |
| commit | d7148eeb647fd55909f985ad14b0176ff1fae335 (patch) | |
| tree | 7f0a577a1573131eed20a5b51a6cd452e2e5d056 /net | |
| parent | f9d3572816ba724129da0ec2ecd590d5c899e86e (diff) | |
ipv4: fix use-after-free in ip_cmsg_recv_dstaddr()
[ Upstream commit 64199fc0a46ba211362472f7f942f900af9492fd ]
Caching ip_hdr(skb) before a call to pskb_may_pull() is buggy,
do not do it.
Fixes: 2efd4fca703a ("ip: in cmsg IP(V6)_ORIGDSTADDR call pskb_may_pull")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Willem de Bruijn <willemb@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/ip_sockglue.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index 88426a6a7a85..3f8caf7d19b8 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -134,7 +134,6 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb) static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb) { struct sockaddr_in sin; - const struct iphdr *iph = ip_hdr(skb); __be16 *ports; int end; @@ -149,7 +148,7 @@ static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb) ports = (__be16 *)skb_transport_header(skb); sin.sin_family = AF_INET; - sin.sin_addr.s_addr = iph->daddr; + sin.sin_addr.s_addr = ip_hdr(skb)->daddr; sin.sin_port = ports[1]; memset(sin.sin_zero, 0, sizeof(sin.sin_zero)); |