From: Joerg Sonnenberger <joerg@bec.de>
Date: Sun, 18 Dec 2016 10:55:30 +0000 (+0100)
Subject: Compute correct size for buffer. Avoid recomputation of lengths.
X-Git-Tag: v3.3.0~81
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d7e5cbde8754a0bb078d683c7906630a76a13832;p=thirdparty%2Flibarchive.git

Compute correct size for buffer. Avoid recomputation of lengths.

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

diff --git a/tar/write.c b/tar/write.c
index 7960487f9..fb8bb92b2 100644
--- a/tar/write.c
+++ b/tar/write.c
@@ -145,18 +145,17 @@ set_writer_options(struct bsdtar *bsdtar, struct archive *a)
 
 	writer_options = getenv(ENV_WRITER_OPTIONS);
 	if (writer_options != NULL) {
+		size_t module_len = sizeof(IGNORE_WRONG_MODULE_NAME) - 1;
+		size_t opt_len = strlen(writer_options) + 1;
 		char *p;
 		/* Set default write options. */
-		p = malloc(sizeof(IGNORE_WRONG_MODULE_NAME)
-		    + strlen(writer_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 filters which are not added to
 		 * the archive write object. */
-		strncpy(p, IGNORE_WRONG_MODULE_NAME,
-		    sizeof(IGNORE_WRONG_MODULE_NAME) -1);
-		strcpy(p + sizeof(IGNORE_WRONG_MODULE_NAME) -1, writer_options);
+		memcpy(p, IGNORE_WRONG_MODULE_NAME, module_len);
+		memcpy(p, writer_options, opt_len);
 		r = archive_write_set_options(a, p);
 		free(p);
 		if (r < ARCHIVE_WARN)
@@ -178,18 +177,18 @@ set_reader_options(struct bsdtar *bsdtar, struct archive *a)
 
 	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 write options. */
-		p = malloc(sizeof(IGNORE_WRONG_MODULE_NAME)
-		    + strlen(reader_options) + 1);
+		if ((p = malloc(module_len + opt_len)) == NULL)
 		if (p == NULL)
 			lafe_errc(1, errno, "Out of memory");
 		/* Prepend magic code to ignore options for
 		 * a format or filters which are not added to
 		 * the archive write 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, reader_options, opt_len);
 		r = archive_read_set_options(a, p);
 		free(p);
 		if (r < ARCHIVE_WARN)