CVE-2023-43040 rgw: Fix bucket validation against POST policies

Bug: https://tracker.ceph.com/issues/63004
Signed-off-by: Joshua Baergen <jbaergen@digitalocean.com>
Origin: https://github.com/ceph/ceph/commit/98bfb71cb38899333deb58dd2562037450fd7fa8.patch
Last-Date: 2024-10-09

It's possible that user could provide a form part as a part of a POST
object upload that uses 'bucket' as a key; in this case, it was
overriding what was being set in the validation env (which is the real
bucket being modified). The result of this is that a user could actually
upload to any bucket accessible by the specified access key by matching
the bucket in the POST policy in said POST form part.

Fix this simply by setting the bucket to the correct value after the
POST form parts are processed, ignoring the form part above if
specified.

Gbp-Pq: Name CVE-2023-43040_rgw_Fix_bucket_validation_against_POST_policies.patch

diff --git a/src/rgw/rgw_rest_s3.cc b/src/rgw/rgw_rest_s3.cc
index 1ed672fa6f9931eacf463f2800525ef5b72851d3..99f33f8a923887c0d0c24439e15d6a1a20ff3640 100644 (file)
--- a/src/rgw/rgw_rest_s3.cc
+++ b/src/rgw/rgw_rest_s3.cc
@@ -2661,10 +2661,6 @@ int RGWPostObj_ObjStore_S3::get_params(optional_yield y)
 
   map_qs_metadata(s);
 
-  ldpp_dout(this, 20) << "adding bucket to policy env: " << s->bucket->get_name()
-                   << dendl;
-  env.add_var("bucket", s->bucket->get_name());
-
   bool done;
   do {
     struct post_form_part part;
@@ -2715,6 +2711,10 @@ int RGWPostObj_ObjStore_S3::get_params(optional_yield y)
     env.add_var(part.name, part_str);
   } while (!done);
 
+  ldpp_dout(this, 20) << "adding bucket to policy env: " << s->bucket->get_name()
+                   << dendl;
+  env.add_var("bucket", s->bucket->get_name());
+
   string object_str;
   if (!part_str(parts, "key", &object_str)) {
     err_msg = "Key not specified";