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

[ Upstream commit 3b2c2ab4ceb82af484310c3087541eab00ea288b ]

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/20260318155847.78065-3-objecting@objecting.org/

Fixes: 950313e ("tools: bootconfig: Add bootconfig command")
Signed-off-by: Josh Law <objecting@objecting.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit 2cf5eff223fc9b720690c16ab763a00788e85c4b)
Signed-off-by: Wentao Guan <guanwentao@uniontech.com>

Author: techyguyperplexable

tools/bootconfig/main.c

@@ -157,8 +157,11 @@ 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);