svn commit: r367401 - stable/12/lib/libc/tests/resolv

[John Baldwin]

Author: jhb
Date: Thu Nov  5 22:35:45 2020
New Revision: 367401
URL: https://svnweb.freebsd.org/changeset/base/367401

Log:
  MFC 365055: Fix a buffer overrun.
  
  getln() returns 'len' valid characters.  line[len] is out of bounds.

Modified:
  stable/12/lib/libc/tests/resolv/resolv_test.c
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/lib/libc/tests/resolv/resolv_test.c
==============================================================================
--- stable/12/lib/libc/tests/resolv/resolv_test.c	Thu Nov  5 21:44:58 2020	(r367400)
+++ stable/12/lib/libc/tests/resolv/resolv_test.c	Thu Nov  5 22:35:45 2020	(r367401)
@@ -77,15 +77,15 @@ load(const char *fname)
 	if ((fp = fopen(fname, "r")) == NULL)
 	ATF_REQUIRE(fp != NULL);
 	while ((line = fgetln(fp, &len)) != NULL) {
-		char c = line[len];
+		char c = line[len - 1];
 		char *ptr;
-		line[len] = '\0';
+		line[len - 1] = '\0';
 		for (ptr = strtok(line, WS); ptr; ptr = strtok(NULL, WS)) {
 			if (ptr == '\0' || ptr[0] == '#')
 				continue;
 			sl_add(hosts, strdup(ptr));
 		}
-		line[len] = c;
+		line[len - 1] = c;
 	}
 
 	(void)fclose(fp);