From: Pavel Shilovsky <piastry@etersoft.ru>
Date: Thu, 14 Apr 2011 18:00:56 +0000 (+0400)
Subject: CIFS: Fix memory over bound bug in cifs_parse_mount_options
X-Git-Tag: v2.6.35.14~178
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=f3b60ef4bcc7b233a816df5fded90e1ba99d47d6;p=karo-tx-linux.git

CIFS: Fix memory over bound bug in cifs_parse_mount_options

commit 4906e50b37e6f6c264e7ee4237343eb2b7f8d16d upstream.

While password processing we can get out of options array bound if
the next character after array is delimiter. The patch adds a check
if we reach the end.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 50d60cc80ce8..a30b080490ed 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -801,8 +801,7 @@ static int
 cifs_parse_mount_options(char *options, const char *devname,
 			 struct smb_vol *vol)
 {
-	char *value;
-	char *data;
+	char *value, *data, *end;
 	unsigned int  temp_len, i, j;
 	char separator[2];
 	short int override_uid = -1;
@@ -845,6 +844,7 @@ cifs_parse_mount_options(char *options, const char *devname,
 	if (!options)
 		return 1;
 
+	end = options + strlen(options);
 	if (strncmp(options, "sep=", 4) == 0) {
 		if (options[4] != 0) {
 			separator[0] = options[4];
@@ -909,6 +909,7 @@ cifs_parse_mount_options(char *options, const char *devname,
 			the only illegal character in a password is null */
 
 			if ((value[temp_len] == 0) &&
+			    (value + temp_len < end) &&
 			    (value[temp_len+1] == separator[0])) {
 				/* reinsert comma */
 				value[temp_len] = separator[0];