From 094704af59677596e09d5205a801aa26ef477378 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ale=C5=A1=20Mat=C4=9Bj?= <amatej@redhat.com>
Date: Thu, 13 Aug 2020 13:48:58 +0200
Subject: [PATCH] Validate path read from repomd.xml (RhBug:1866500)

---
 librepo/yum.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/librepo/yum.c b/librepo/yum.c
index 6d36562..a5eeb9c 100644
--- a/librepo/yum.c
+++ b/librepo/yum.c
@@ -22,6 +22,7 @@
 #define _DEFAULT_SOURCE
 
 #include <stdio.h>
+#include <libgen.h>
 #include <assert.h>
 #include <stdlib.h>
 #include <errno.h>
@@ -573,6 +574,21 @@ prepare_repo_download_targets(LrHandle *handle,
         if (!lr_yum_repomd_record_enabled(handle, record->type, repomd->records))
             continue;
 
+        char *dest_dir = realpath(handle->destdir, NULL);
+        path = lr_pathconcat(handle->destdir, record->location_href, NULL);
+        char *requested_dir = realpath(dirname(path), NULL);
+        lr_free(path);
+        if (!g_str_has_prefix(requested_dir, dest_dir)) {
+            g_debug("%s: Invalid path: %s", __func__, record->location_href);
+            g_set_error(err, LR_YUM_ERROR, LRE_IO, "Invalid path: %s", record->location_href);
+            g_slist_free_full(*targets, (GDestroyNotify) lr_downloadtarget_free);
+            free(requested_dir);
+            free(dest_dir);
+            return FALSE;
+        }
+        free(requested_dir);
+        free(dest_dir);
+
         path = lr_pathconcat(destdir, record->location_href, NULL);
         fd = open(path, O_CREAT|O_TRUNC|O_RDWR, 0666);
         if (fd < 0) {
-- 
2.28.0