diff options
| author | Hannes Frederic Sowa <hannes@stressinduktion.org> | 2013-11-18 10:07:45 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-11-19 01:02:03 +0400 |
| commit | cf970c002d270c36202bd5b9c2804d3097a52da0 (patch) | |
| tree | 5a8f07507f36caef9274c29504f428fef07f9760 | |
| parent | 4861292f730d7c461758575e2557e285a1d4521e (diff) | |
| download | linux-cf970c002d270c36202bd5b9c2804d3097a52da0.tar.xz | |
ping: prevent NULL pointer dereference on write to msg_name
A plain read() on a socket does set msg->msg_name to NULL. So check for
NULL pointer first.
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/ping.c | 34 |
1 files changed, 19 insertions, 15 deletions
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index aacefa0caa36..91bfe0437e7a 100644 --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -870,11 +870,13 @@ int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, if (family == AF_INET) { struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; - sin->sin_family = AF_INET; - sin->sin_port = 0 /* skb->h.uh->source */; - sin->sin_addr.s_addr = ip_hdr(skb)->saddr; - memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); - *addr_len = sizeof(*sin); + if (sin) { + sin->sin_family = AF_INET; + sin->sin_port = 0 /* skb->h.uh->source */; + sin->sin_addr.s_addr = ip_hdr(skb)->saddr; + memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); + *addr_len = sizeof(*sin); + } if (isk->cmsg_flags) ip_cmsg_recv(msg, skb); @@ -886,16 +888,18 @@ int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)msg->msg_name; - sin6->sin6_family = AF_INET6; - sin6->sin6_port = 0; - sin6->sin6_addr = ip6->saddr; - sin6->sin6_flowinfo = 0; - if (np->sndflow) - sin6->sin6_flowinfo = ip6_flowinfo(ip6); - - sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr, - IP6CB(skb)->iif); - *addr_len = sizeof(*sin6); + if (sin6) { + sin6->sin6_family = AF_INET6; + sin6->sin6_port = 0; + sin6->sin6_addr = ip6->saddr; + sin6->sin6_flowinfo = 0; + if (np->sndflow) + sin6->sin6_flowinfo = ip6_flowinfo(ip6); + sin6->sin6_scope_id = + ipv6_iface_scope_id(&sin6->sin6_addr, + IP6CB(skb)->iif); + *addr_len = sizeof(*sin6); + } if (inet6_sk(sk)->rxopt.all) pingv6_ops.ip6_datagram_recv_ctl(sk, msg, skb); |