[PATCH] fix a kernel infoleak in x25 module

[PATCH] fix a kernel infoleak in x25 module

[Kangjie Lu]

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>
---
 net/x25/x25_facilities.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/x25/x25_facilities.c b/net/x25/x25_facilities.c
index 2844031..a1c30c6 100644
--- a/net/x25/x25_facilities.c
+++ b/net/x25/x25_facilities.c
@@ -278,6 +278,7 @@ 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)
-- 
1.9.1

Re: [PATCH] fix a kernel infoleak in x25 module

[David Miller]

From: Kangjie Lu <kangjielu@gmail.com>
Date: Sun,  8 May 2016 12:10:14 -0400

> 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>

Applied and queued up for -stable thanks.

Please start formatting your Subject lines properly, I've been fixing
all of them up by hand.

You should specify a subsystem name prefix, then a ":" character, then
a space, then a description of your change.  For example, for this
patch an appropriate Subject would have been:

	[PATCH] x25: Fix a kernel infoleak in x25_negotiate_facilities().

Thanks.