From: Simon Wilkinson <sxw@your-file-system.com>
Date: Sat, 2 Mar 2013 13:01:14 +0000 (+0000)
Subject: auth: Don't overflow buffer in CompFindUser
X-Git-Tag: upstream/1.8.0_pre1^2~1321
X-Git-Url: https://git.michaelhowe.org/gitweb/?a=commitdiff_plain;h=cc95fca8e16f83d7dda3f09a5133dc9294299d61;p=packages%2Fo%2Fopenafs.git

auth: Don't overflow buffer in CompFindUser

The fullname buffer in CompFindUser is theoretically big enough
to take the data usually supplied to it. However, play it safe by
using strlcat and strlcpy to catch buffer overflows.

Caught by coverity (#985771)

Change-Id: Icc80d012b61ae90e1a62a814f7a6d552bb264294
Reviewed-on: http://gerrit.openafs.org/9543
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
---

diff --git a/src/auth/userok.c b/src/auth/userok.c
index eb98b3236..f66acf1df 100644
--- a/src/auth/userok.c
+++ b/src/auth/userok.c
@@ -553,7 +553,9 @@ CompFindUser(struct afsconf_dir *adir, char *name, char *sep, char *inst,
     if (!name || !name[0]) {
 	return 0;
     }
-    strcpy(fullname, name);
+
+    if (strlcpy(fullname, name, sizeof(fullname)) >= sizeof(fullname))
+	return 0;
 
     /* might have instance */
     if (inst && inst[0]) {
@@ -561,14 +563,20 @@ CompFindUser(struct afsconf_dir *adir, char *name, char *sep, char *inst,
 	    return 0;
 	}
 
-	strcat(fullname, sep);
-	strcat(fullname, inst);
+	if (strlcat(fullname, sep, sizeof(fullname)) >= sizeof(fullname))
+	    return 0;
+
+	if (strlcat(fullname, inst, sizeof(fullname)) >= sizeof(fullname))
+	    return 0;
     }
 
     /* might have realm */
     if (realm && realm[0]) {
-	strcat(fullname, "@");
-	strcat(fullname, realm);
+	if (strlcat(fullname, "@", sizeof(fullname)) >= sizeof(fullname))
+	    return 0;
+
+	if (strlcat(fullname, realm, sizeof(fullname)) >= sizeof(fullname))
+	    return 0;
     }
 
     testId = rx_identity_new(RX_ID_KRB4, fullname, fullname, strlen(fullname));