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.
Change-Id: I3773934fb633157ce5011d2f10900b7caef73733
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Git-commit: cf970c002d270c36202bd5b9c2804d3097a52da0
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Avijit Kanti Das <avijitnsec@codeaurora.org>
Signed-off-by: Nirmal Abraham <nabrah@codeaurora.org>
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 7f38d35..6241358 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -879,10 +879,12 @@
/* Copy the address and add cmsg data. */
if (family == AF_INET) {
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));
+ 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));
+ }
if (isk->cmsg_flags)
ip_cmsg_recv(msg, skb);
@@ -892,17 +894,19 @@
struct ipv6_pinfo *np = inet6_sk(sk);
struct ipv6hdr *ip6 = ipv6_hdr(skb);
sin6 = (struct sockaddr_in6 *) msg->msg_name;
- sin6->sin6_family = AF_INET6;
- sin6->sin6_port = 0;
- sin6->sin6_addr = ip6->saddr;
+ if (sin6) {
+ sin6->sin6_family = AF_INET6;
+ sin6->sin6_port = 0;
+ sin6->sin6_addr = ip6->saddr;
- if (np->sndflow)
- sin6->sin6_flowinfo =
- *(__be32 *)ip6 & IPV6_FLOWINFO_MASK;
+ if (np->sndflow)
+ sin6->sin6_flowinfo =
+ *(__be32 *)ip6 & IPV6_FLOWINFO_MASK;
- if (__ipv6_addr_needs_scope_id(
- ipv6_addr_type(&sin6->sin6_addr)))
- sin6->sin6_scope_id = IP6CB(skb)->iif;
+ if (__ipv6_addr_needs_scope_id(
+ ipv6_addr_type(&sin6->sin6_addr)))
+ sin6->sin6_scope_id = IP6CB(skb)->iif;
+ }
if (inet6_sk(sk)->rxopt.all)
pingv6_ops.datagram_recv_ctl(sk, msg, skb);