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authorHannes Frederic Sowa <hannes@stressinduktion.org>2013-11-18 04:20:45 +0100
committerDavid S. Miller <davem@davemloft.net>2013-11-18 15:12:03 -0500
commitbceaa90240b6019ed73b49965eac7d167610be69 (patch)
treef68c10948efff147a7b987369f1e720ad76f411b /net/ipv6
parentbcd081a3aef1f7f3786067ae8dd26aaa1cf85153 (diff)
downloadlinux-bceaa90240b6019ed73b49965eac7d167610be69.tar.bz2
inet: prevent leakage of uninitialized memory to user in recv syscalls
Only update *addr_len when we actually fill in sockaddr, otherwise we can return uninitialized memory from the stack to the caller in the recvfrom, recvmmsg and recvmsg syscalls. Drop the the (addr_len == NULL) checks because we only get called with a valid addr_len pointer either from sock_common_recvmsg or inet_recvmsg. If a blocking read waits on a socket which is concurrently shut down we now return zero and set msg_msgnamelen to 0. Reported-by: mpb <mpb.mail@gmail.com> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6')
-rw-r--r--net/ipv6/raw.c4
-rw-r--r--net/ipv6/udp.c5
2 files changed, 2 insertions, 7 deletions
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index 3c00842b0079..e24ff1df0401 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -465,9 +465,6 @@ static int rawv6_recvmsg(struct kiocb *iocb, struct sock *sk,
if (flags & MSG_OOB)
return -EOPNOTSUPP;
- if (addr_len)
- *addr_len=sizeof(*sin6);
-
if (flags & MSG_ERRQUEUE)
return ipv6_recv_error(sk, msg, len);
@@ -506,6 +503,7 @@ static int rawv6_recvmsg(struct kiocb *iocb, struct sock *sk,
sin6->sin6_flowinfo = 0;
sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr,
IP6CB(skb)->iif);
+ *addr_len = sizeof(*sin6);
}
sock_recv_ts_and_drops(msg, sk, skb);
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index f3893e897f72..81eb8cf8389b 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -392,9 +392,6 @@ int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk,
int is_udp4;
bool slow;
- if (addr_len)
- *addr_len = sizeof(struct sockaddr_in6);
-
if (flags & MSG_ERRQUEUE)
return ipv6_recv_error(sk, msg, len);
@@ -480,7 +477,7 @@ try_again:
ipv6_iface_scope_id(&sin6->sin6_addr,
IP6CB(skb)->iif);
}
-
+ *addr_len = sizeof(*sin6);
}
if (is_udp4) {
if (inet->cmsg_flags)