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| author | Eric Dumazet <edumazet@google.com> | 2018-09-30 21:33:39 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-10-18 10:16:17 +0300 |
| commit | 32b193216e185a3ba817a179f29a53a9973665a9 (patch) | |
| tree | c825ea0bc82c6c6915a1a7de308f1d4a86b32aab | |
| parent | deb33b68f40e788c974acf61bc220dc077cb8032 (diff) | |
| download | linux-32b193216e185a3ba817a179f29a53a9973665a9.tar.xz | |
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>
| -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 048d5f6dd320..4ef92ebc4f6d 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -147,7 +147,6 @@ 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; @@ -162,7 +161,7 @@ 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)); |