From: Joerg Sonnenberger <joerg@bec.de>
Date: Sun, 18 Dec 2016 10:50:10 +0000 (+0100)
Subject: Allocate memory precisely. Avoid recomputions of sizes.
X-Git-Tag: v3.3.0~82
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7f6565656cf20c74057289d784f548ffd189b416;p=thirdparty%2Flibarchive.git

Allocate memory precisely. Avoid recomputions of sizes.

Based on Coverity report from pull request #844.
---

diff --git a/tar/read.c b/tar/read.c
index e94cb3da8..3c6cb0c13 100644
--- a/tar/read.c
+++ b/tar/read.c
@@ -188,18 +188,17 @@ read_archive(struct bsdtar *bsdtar, char mode, struct archive *writer)
 
 	reader_options = getenv(ENV_READER_OPTIONS);
 	if (reader_options != NULL) {
+		size_t module_len = sizeof(IGNORE_WRONG_MODULE_NAME) - 1;
+		size_t opt_len = strlen(reader_options) + 1;
 		char *p;
 		/* Set default read options. */
-		p = (char *)malloc(sizeof(IGNORE_WRONG_MODULE_NAME)
-		    + strlen(reader_options) + 1);
-		if (p == NULL)
+		if ((p = malloc(module_len + opt_len)) == NULL)
 			lafe_errc(1, errno, "Out of memory");
 		/* Prepend magic code to ignore options for
 		 * a format or  modules which are not added to
 		 *  the archive read object. */
-		strncpy(p, IGNORE_WRONG_MODULE_NAME,
-		    sizeof(IGNORE_WRONG_MODULE_NAME) -1);
-		strcpy(p + sizeof(IGNORE_WRONG_MODULE_NAME) -1, reader_options);
+		memcpy(p, IGNORE_WRONG_MODULE_NAME, module_len);
+		memcpy(p + module_len, reader_options, opt_len);
 		r = archive_read_set_options(a, p);
 		free(p);
 		if (r == ARCHIVE_FATAL)