svn commit: samba r11797 - in branches/SAMBA_4_0/source/lib/replace: .

[jra at samba.org]

Author: jra
Date: 2005-11-19 01:12:10 +0000 (Sat, 19 Nov 2005)
New Revision: 11797

WebSVN: http://websvn.samba.org/cgi-bin/viewcvs.cgi?view=rev&root=samba&rev=11797

Log:
Added OpenSSH fix for "%.*s" format crash. From Darren Tucker
<dtucker at zip.com.au>
Jeremy.

Modified:
   branches/SAMBA_4_0/source/lib/replace/snprintf.c


Changeset:
Modified: branches/SAMBA_4_0/source/lib/replace/snprintf.c
===================================================================
--- branches/SAMBA_4_0/source/lib/replace/snprintf.c	2005-11-18 23:48:51 UTC (rev 11796)
+++ branches/SAMBA_4_0/source/lib/replace/snprintf.c	2005-11-19 01:12:10 UTC (rev 11797)
@@ -53,6 +53,12 @@
  *    got rid of fcvt code (twas buggy and made testing harder)
  *    added C99 semantics
  *
+ * Darren Tucker (dtucker at zip.com.au)
+ *    Fix bug allowing read overruns of the source string with "%.*s"
+ *    Usually harmless unless the read runs outside the process' allocation
+ *    (eg if your malloc does guard pages) in which case it will segfault.
+ *    From OpenSSH.  Also added test for same.
+ *
  **************************************************************/
 
 #ifndef NO_CONFIG_H /* for some tests */
@@ -436,7 +442,7 @@
 		value = "<NULL>";
 	}
 
-	for (strln = 0; value[strln]; ++strln); /* strlen */
+	for (strln = 0; strln < max && value[strln]; ++strln); /* strlen */
 	padlen = min - strln;
 	if (padlen < 0) 
 		padlen = 0;
@@ -851,6 +857,7 @@
 {
 	char buf1[1024];
 	char buf2[1024];
+	char *buf3;
 	char *fp_fmt[] = {
 		"%1.1f",
 		"%-1.5f",
@@ -959,6 +966,20 @@
 		}
 	}
 
+#define BUFSZ 2048
+
+	if ((buf3 = malloc(BUFSZ)) == NULL) {
+		fail++;
+	} else {
+		num++;
+		memset(buf3, 'a', BUFSZ);
+		snprintf(buf1, sizeof(buf1), "%.*s", 1, buf3);
+		if (strcmp(buf1, "a") != 0) {
+			printf("length limit buf1 '%s' expected 'a'\n", buf1);
+			fail++;
+		}
+	}
+
 	printf ("%d tests failed out of %d.\n", fail, num);
 
 	printf("seeing how many digits we support\n");