diff mbox series

[qemu,02/10] hw/cxl: Check input includes at least the header in cmd_features_set_feature()

Message ID 20241101133917.27634-3-Jonathan.Cameron@huawei.com (mailing list archive)
State New
Headers show
Series hw/cxl: Mailbox input parser hardening against invalid input. | expand

Commit Message

Jonathan Cameron Nov. 1, 2024, 1:39 p.m. UTC
A buggy guest might write an insufficiently large message.
Check the header is present. Whilst zero data after the header is very
odd it will just result in failure to copy any data.

Reported-by: Esifiel <esifiel@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 hw/cxl/cxl-mailbox-utils.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Fan Ni Nov. 5, 2024, 8:59 p.m. UTC | #1
On Fri, Nov 01, 2024 at 01:39:09PM +0000, Jonathan Cameron wrote:
> A buggy guest might write an insufficiently large message.
> Check the header is present. Whilst zero data after the header is very
> odd it will just result in failure to copy any data.
> 
> Reported-by: Esifiel <esifiel@gmail.com>
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> ---

Reviewed-by: Fan Ni <fan.ni@samsung.com>

>  hw/cxl/cxl-mailbox-utils.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
> index 17924410dd..e63140aefe 100644
> --- a/hw/cxl/cxl-mailbox-utils.c
> +++ b/hw/cxl/cxl-mailbox-utils.c
> @@ -1238,6 +1238,9 @@ static CXLRetCode cmd_features_set_feature(const struct cxl_cmd *cmd,
>      CXLType3Dev *ct3d;
>      uint16_t count;
>  
> +    if (len_in < sizeof(*hdr)) {
> +        return CXL_MBOX_INVALID_PAYLOAD_LENGTH;
> +    }
>  
>      if (!object_dynamic_cast(OBJECT(cci->d), TYPE_CXL_TYPE3)) {
>          return CXL_MBOX_UNSUPPORTED;
> -- 
> 2.43.0
>
diff mbox series

Patch

diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index 17924410dd..e63140aefe 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -1238,6 +1238,9 @@  static CXLRetCode cmd_features_set_feature(const struct cxl_cmd *cmd,
     CXLType3Dev *ct3d;
     uint16_t count;
 
+    if (len_in < sizeof(*hdr)) {
+        return CXL_MBOX_INVALID_PAYLOAD_LENGTH;
+    }
 
     if (!object_dynamic_cast(OBJECT(cci->d), TYPE_CXL_TYPE3)) {
         return CXL_MBOX_UNSUPPORTED;