From: David S. Miller <davem@davemloft.net>
Date: Fri, 24 Mar 2006 06:54:18 +0000 (-0800)
Subject: [PATCH] NET: Ensure device name passed to SO_BINDTODEVICE is NULL terminated.
X-Git-Tag: v2.6.15.7~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=107d25ba4fcacf8e29bcad240b95fd9ef7314dac;p=thirdparty%2Fkernel%2Fstable.git

[PATCH] NET: Ensure device name passed to SO_BINDTODEVICE is NULL terminated.

The user can pass us arbitrary garbage so we should ensure the
string they give us is null terminated before we pass it on
to dev_get_by_index() et al.

Found by Solar Designer.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/net/core/sock.c b/net/core/sock.c
index 13cc3be4f056f..2a3e235bd1bc5 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -403,8 +403,9 @@ set_rcvbuf:
 			if (!valbool) {
 				sk->sk_bound_dev_if = 0;
 			} else {
-				if (optlen > IFNAMSIZ) 
-					optlen = IFNAMSIZ; 
+				if (optlen > IFNAMSIZ - 1)
+					optlen = IFNAMSIZ - 1;
+				memset(devname, 0, sizeof(devname));
 				if (copy_from_user(devname, optval, optlen)) {
 					ret = -EFAULT;
 					break;