net: fix a kernel infoleak in x25 module

[ Upstream commit 79e48650320e6fba48369fccf13fd045315b19b8 ]

Stack object "dte_facilities" is allocated in x25_rx_call_request(),
which is supposed to be initialized in x25_negotiate_facilities.
However, 5 fields (8 bytes in total) are not initialized. This
object is then copied to userland via copy_to_user, thus infoleak
occurs.

Signed-off-by: Kangjie Lu <kjlu@gatech.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/x25/x25_facilities.c b/net/x25/x25_facilities.c
index 7ecd04c21360994627f7b9ec0231bf454510fd46..997ff7b2509b49a3da6d3183fe65512f8f4caa38 100644 (file)
--- a/net/x25/x25_facilities.c
+++ b/net/x25/x25_facilities.c
@@ -277,6 +277,7 @@ int x25_negotiate_facilities(struct sk_buff *skb, struct sock *sk,
 
        memset(&theirs, 0, sizeof(theirs));
        memcpy(new, ours, sizeof(*new));
+       memset(dte, 0, sizeof(*dte));
 
        len = x25_parse_facilities(skb, &theirs, dte, &x25->vc_facil_mask);
        if (len < 0)