From: David van Moolenbroek <david@minix3.org>
Date: Sat, 29 Aug 2009 08:22:50 +0000 (+0000)
Subject: VFS: fetch_name() buffer underflow (reported by John Peace, bug #305)
X-Git-Tag: v3.1.5~171
X-Git-Url: http://zhaoyanbai.com/repos/?a=commitdiff_plain;h=42f0bf7dda713f1447f2369b2f925ade7266d16d;p=minix.git

VFS: fetch_name() buffer underflow (reported by John Peace, bug #305)
---

diff --git a/servers/vfs/utility.c b/servers/vfs/utility.c
index 6427bbaba..81b3651e2 100644
--- a/servers/vfs/utility.c
+++ b/servers/vfs/utility.c
@@ -34,7 +34,7 @@ int flag;			/* M3 means path may be in message */
  * If it is not, go copy it from user space.
  */
   register char *rpu, *rpm;
-  int r;
+  int r, count;
 
   if (len > PATH_MAX) {
 #if 0
@@ -61,7 +61,8 @@ int flag;			/* M3 means path may be in message */
 	/* Just copy the path from the message to 'user_fullpath'. */
 	rpu = &user_fullpath[0];
 	rpm = m_in.pathname;		/* contained in input message */
-	do { *rpu++ = *rpm++; } while (--len);
+	count = len;
+	do { *rpu++ = *rpm++; } while (--count);
 	r = OK;
   } else {
 	/* String is not contained in the message.  Get it from user space. */