tools/bootconfig: fix fd leak in load_xbc_file() on fstat failure

[ Upstream commit 3b2c2ab ]

If fstat() fails after open() succeeds, the function returns without
closing the file descriptor. Also preserve errno across close(), since
close() may overwrite it before the error is returned.

Link: https://lore.kernel.org/all/[email protected]/

Fixes: 950313e ("tools: bootconfig: Add bootconfig command")
Signed-off-by: Josh Law <[email protected]>
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>

Author: techyguyperplexable

tools/bootconfig/main.c

@@ -162,8 +162,11 @@ static int load_xbc_file(const char *path, char **buf)
 	if (fd < 0)
 		return -errno;
 	ret = fstat(fd, &stat);
-	if (ret < 0)
-		return -errno;
+	if (ret < 0) {
+		ret = -errno;
+		close(fd);
+		return ret;
+	}
 
 	ret = load_xbc_fd(fd, buf, stat.st_size);