[3.13.y-ckt stable] Patch "sunrpc/cache: fix off-by-one in qword_get()" has been added to the 3.13.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    sunrpc/cache: fix off-by-one in qword_get()

to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt36.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From fb428c537d643f08d77577a16100895492d3db0a Mon Sep 17 00:00:00 2001
From: Stefan Hajnoczi <stefanha at redhat.com>
Date: Thu, 18 Feb 2016 18:55:54 +0000
Subject: sunrpc/cache: fix off-by-one in qword_get()

commit b7052cd7bcf3c1478796e93e3dff2b44c9e82943 upstream.

The qword_get() function NUL-terminates its output buffer.  If the input
string is in hex format \xXXXX... and the same length as the output
buffer, there is an off-by-one:

  int qword_get(char **bpp, char *dest, int bufsize)
  {
      ...
      while (len < bufsize) {
          ...
          *dest++ = (h << 4) | l;
          len++;
      }
      ...
      *dest = '\0';
      return len;
  }

This patch ensures the NUL terminator doesn't fall outside the output
buffer.

Signed-off-by: Stefan Hajnoczi <stefanha at redhat.com>
Signed-off-by: J. Bruce Fields <bfields at redhat.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/sunrpc/cache.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 8a6e3b0..f3e2b7d 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -1232,7 +1232,7 @@ int qword_get(char **bpp, char *dest, int bufsize)
 	if (bp[0] == '\\' && bp[1] == 'x') {
 		/* HEX STRING */
 		bp += 2;
-		while (len < bufsize) {
+		while (len < bufsize - 1) {
 			int h, l;

 			h = hex_to_bin(bp[0]);
--
2.7.0