From: erickson <erickson@9efc2488-bf62-4759-914b-345cdb29e865>
Date: Mon, 16 Jul 2007 13:08:55 +0000 (+0000)
Subject: Merged revisions 1036-1038 via svnmerge from
X-Git-Url: https://old-git.evergreen-ils.org/?a=commitdiff_plain;h=e7e54ad960ae93bab14a847453a4927a5f94ac73;p=OpenSRF.git

Merged revisions 1036-1038 via svnmerge from
svn://svn.open-ils.org/OpenSRF/trunk

........
  r1038 | erickson | 2007-07-16 09:03:48 -0400 (Mon, 16 Jul 2007) | 25 lines

  Patch from Scott McKellar to repair srfsh buffer overflow:

  The potential overflow occurs in handle_introspection(), which in the
  existing code uses sprintf() to insert some user-supplied input into a
  fixed length buffer, without checking the length of the user-supplied
  input.

  There's always more than one way to fix this sort of thing.  For
  example I could have formatted into a growing_buffer.  Instead, I
  chose to calculate the necessary buffer size and then declare a
  variable-length buffer.  That way I avoid two mallocs and two frees.

  I tested this change by inserting some temporary printfs to capture
  the commands being sent to parse_request().  The outputs before and
  after the change were identical.

  There's at least one more such potential overflow that I haven't
  addressed yet.  It's near the top of handle_login(), where we
  use sprintf() to insert a username into a fixed length buffer.
  There may be others that I haven't noticed yet.

  Scott McKellar
  http://home.swbell.net/mck9/ct/
........


git-svn-id: svn://svn.open-ils.org/OpenSRF/branches/new-json2@1039 9efc2488-bf62-4759-914b-345cdb29e865
---

diff --git a/src/srfsh/srfsh.c b/src/srfsh/srfsh.c
index d2630fa..2d41125 100644
--- a/src/srfsh/srfsh.c
+++ b/src/srfsh/srfsh.c
@@ -324,25 +324,30 @@ static int parse_request( char* request ) {
 
 static int handle_introspect(char* words[]) {
 
-	if(words[1] && words[2]) {
-		fprintf(stderr, "--> %s\n", words[1]);
-		char buf[256];
-		memset(buf,0,256);
-		sprintf( buf, "request %s opensrf.system.method %s", words[1], words[2] );
+	if( ! words[1] )
+		return 0;
+
+	fprintf(stderr, "--> %s\n", words[1]);
+
+	// Build a command in a suitably-sized
+	// buffer and then parse it
+	
+	size_t len;
+	if( words[2] ) {
+		static const char text[] = "request %s opensrf.system.method %s";
+		len = sizeof( text ) + strlen( words[1] ) + strlen( words[2] );
+		char buf[len];
+		sprintf( buf, text, words[1], words[2] );
 		return parse_request( buf );
 
 	} else {
-	
-		if(words[1]) {
-			fprintf(stderr, "--> %s\n", words[1]);
-			char buf[256];
-			memset(buf,0,256);
-			sprintf( buf, "request %s opensrf.system.method.all", words[1] );
-			return parse_request( buf );
-		}
-	}
+		static const char text[] = "request %s opensrf.system.method.all";
+		len = sizeof( text ) + strlen( words[1] );
+		char buf[len];
+		sprintf( buf, text, words[1] );
+		return parse_request( buf );
 
-	return 0;
+	}
 }