path: root/net/phonet
diff options
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/phonet
parentbcd081a3aef1f7f3786067ae8dd26aaa1cf85153 (diff)
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/phonet')
1 files changed, 4 insertions, 5 deletions
diff --git a/net/phonet/datagram.c b/net/phonet/datagram.c
index 12c30f3e643e..38946b26e471 100644
--- a/net/phonet/datagram.c
+++ b/net/phonet/datagram.c
@@ -139,9 +139,6 @@ static int pn_recvmsg(struct kiocb *iocb, struct sock *sk,
goto out_nofree;
- if (addr_len)
- *addr_len = sizeof(sa);
skb = skb_recv_datagram(sk, flags, noblock, &rval);
if (skb == NULL)
goto out_nofree;
@@ -162,8 +159,10 @@ static int pn_recvmsg(struct kiocb *iocb, struct sock *sk,
rval = (flags & MSG_TRUNC) ? skb->len : copylen;
- if (msg->msg_name != NULL)
- memcpy(msg->msg_name, &sa, sizeof(struct sockaddr_pn));
+ if (msg->msg_name != NULL) {
+ memcpy(msg->msg_name, &sa, sizeof(sa));
+ *addr_len = sizeof(sa);
+ }
skb_free_datagram(sk, skb);

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