hw/cxl: Check that writes do not go beyond end of target attributes

In cmd_features_set_feature() the an offset + data size schemed
is used to allow for large features.  Ensure this does not write
beyond the end fo the buffers used to accumulate the full feature
attribute set.

Reported-by: Esifiel <esifiel@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20241101133917.27634-9-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index a40d81219c..078782e8b9 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -1292,6 +1292,11 @@ static CXLRetCode cmd_features_set_feature(const struct cxl_cmd *cmd,
 
         ps_set_feature = (void *)payload_in;
         ps_write_attrs = &ps_set_feature->feat_data;
+
+        if ((uint32_t)hdr->offset + bytes_to_copy >
+            sizeof(ct3d->patrol_scrub_wr_attrs)) {
+            return CXL_MBOX_INVALID_PAYLOAD_LENGTH;
+        }
         memcpy((uint8_t *)&ct3d->patrol_scrub_wr_attrs + hdr->offset,
                ps_write_attrs,
                bytes_to_copy);
@@ -1314,6 +1319,11 @@ static CXLRetCode cmd_features_set_feature(const struct cxl_cmd *cmd,
 
         ecs_set_feature = (void *)payload_in;
         ecs_write_attrs = ecs_set_feature->feat_data;
+
+        if ((uint32_t)hdr->offset + bytes_to_copy >
+            sizeof(ct3d->ecs_wr_attrs)) {
+            return CXL_MBOX_INVALID_PAYLOAD_LENGTH;
+        }
         memcpy((uint8_t *)&ct3d->ecs_wr_attrs + hdr->offset,
                ecs_write_attrs,
                bytes_to_copy);