--- busybox-1.10.1/archival/libunarchive/get_header_tar.c
+++ busybox-1.10.1/archival/libunarchive/get_header_tar.c
@@ -24,18 +24,20 @@
 };
 #endif
 
-/* NB: _DESTROYS_ str[len] character! */
 static unsigned long long getOctal(char *str, int len)
 {
 	unsigned long long v;
+	char last;
 	/* Actually, tar header allows leading spaces also.
 	 * Oh well, we will be liberal and skip this...
 	 * The only downside probably is that we allow "-123" too :)
 	if (*str < '0' || *str > '7')
 		bb_error_msg_and_die("corrupted octal value in tar header");
 	*/
+	last = str[len];
 	str[len] = '\0';
 	v = strtoull(str, &str, 8);
+	str[len] = last;
 	if (*str && (!ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY || *str != ' '))
 		bb_error_msg_and_die("corrupted octal value in tar header");
 	return v;