From 301a6a317797ca362951ea21da397c05236f0070 Mon Sep 17 00:00:00 2001
From: Steve French <sfrench@us.ibm.com>
Date: Sat, 6 Feb 2010 07:08:53 +0000
Subject: [CIFS] Maximum username length check in session setup does not match

Fix length check reported by D. Binderman (see below)

d binderman <dcb314@hotmail.com> wrote:
>
> I just ran the sourceforge tool cppcheck over the source code of the
> new Linux kernel 2.6.33-rc6
>
> It said
>
> [./cifs/sess.c:250]: (error) Buffer access out-of-bounds

May turn out to be harmless, but best to be safe. Note max
username length is defined to 32 due to Linux (Windows
maximum is 20).

Signed-off-by: Steve French <sfrench@us.ibm.com>
---
 fs/cifs/sess.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

(limited to 'fs')

diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index 7085a6275c4c..aaa9c1c5a5bd 100644
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -223,9 +223,9 @@ static void unicode_ssetup_strings(char **pbcc_area, struct cifsSesInfo *ses,
 		/* null user mount */
 		*bcc_ptr = 0;
 		*(bcc_ptr+1) = 0;
-	} else { /* 300 should be long enough for any conceivable user name */
+	} else {
 		bytes_ret = cifs_strtoUCS((__le16 *) bcc_ptr, ses->userName,
-					  300, nls_cp);
+					  MAX_USERNAME_SIZE, nls_cp);
 	}
 	bcc_ptr += 2 * bytes_ret;
 	bcc_ptr += 2; /* account for null termination */
@@ -246,11 +246,10 @@ static void ascii_ssetup_strings(char **pbcc_area, struct cifsSesInfo *ses,
 	/* copy user */
 	if (ses->userName == NULL) {
 		/* BB what about null user mounts - check that we do this BB */
-	} else { /* 300 should be long enough for any conceivable user name */
-		strncpy(bcc_ptr, ses->userName, 300);
+	} else {
+		strncpy(bcc_ptr, ses->userName, MAX_USERNAME_SIZE);
 	}
-	/* BB improve check for overflow */
-	bcc_ptr += strnlen(ses->userName, 300);
+	bcc_ptr += strnlen(ses->userName, MAX_USERNAME_SIZE);
 	*bcc_ptr = 0;
 	bcc_ptr++; /* account for null termination */
 
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