From: Patrick Cheng <patcheng@users.noreply.github.com>
Date: Sun, 24 Feb 2019 19:32:06 +0000 (-0800)
Subject: fix dereferencing null pointer in file_new()
X-Git-Tag: v3.4.0~120
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=57742aa0df9b4dbef6532a1b8393056ae4d798bc;p=thirdparty%2Flibarchive.git

fix dereferencing null pointer in file_new()

file_new() sets file to NULL first.
when file_new() fails, file is set to NULL if it doesn't need to be freed
so, only free when need to. otherwise would deference a null pointer.

Found this from clang's analyzer
Fixes #1140
---

diff --git a/libarchive/archive_write_set_format_7zip.c b/libarchive/archive_write_set_format_7zip.c
index f63a2266a..92a87f74e 100644
--- a/libarchive/archive_write_set_format_7zip.c
+++ b/libarchive/archive_write_set_format_7zip.c
@@ -439,7 +439,8 @@ _7z_write_header(struct archive_write *a, struct archive_entry *entry)
 
 	r = file_new(a, entry, &file);
 	if (r < ARCHIVE_WARN) {
-		file_free(file);
+		if (file != NULL)
+			file_free(file);
 		return (r);
 	}
 	if (file->size == 0 && file->dir) {