ip: zero sockaddr returned on error queue
The sockaddr is returned in IP(V6)_RECVERR as part of errhdr. That
structure is defined and allocated on the stack as
struct {
struct sock_extended_err ee;
struct sockaddr_in(6) offender;
} errhdr;
The second part is only initialized for certain SO_EE_ORIGIN values.
Always initialize it completely.
An MTU exceeded error on a SOCK_RAW/IPPROTO_RAW is one example that
would return uninitialized bytes.
Signed-off-by: Willem de Bruijn <willemb@google.com>
----
Also verified that there is no padding between errhdr.ee and
errhdr.offender that could leak additional kernel data.
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 8a89c73..6b85adb 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -461,17 +461,13 @@
memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
sin = &errhdr.offender;
- sin->sin_family = AF_UNSPEC;
+ memset(sin, 0, sizeof(*sin));
if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
ipv4_pktinfo_prepare_errqueue(sk, skb, serr->ee.ee_origin)) {
- struct inet_sock *inet = inet_sk(sk);
-
sin->sin_family = AF_INET;
sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
- sin->sin_port = 0;
- memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
- if (inet->cmsg_flags)
+ if (inet_sk(sk)->cmsg_flags)
ip_cmsg_recv(msg, skb);
}