[v3] hw/sd/sdcard: Fix CVE-2020-13253 & cleanups

[PATCH v3 04/11] hw/sd/sdcard: Restrict Class 6 commands to SCSD cards

Posted by Philippe Mathieu-Daudé 5 years, 8 months ago

From: Philippe Mathieu-Daudé <f4bug@amsat.org>

Only SCSD cards support Class 6 (Block Oriented Write Protection)
commands.

  "SD Specifications Part 1 Physical Layer Simplified Spec. v3.01"

  4.3.14 Command Functional Difference in Card Capacity Types

  * Write Protected Group

  SDHC and SDXC do not support write-protected groups. Issuing
  CMD28, CMD29 and CMD30 generates the ILLEGAL_COMMAND error.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/sd/sd.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index 90d5ff6209..4cc1ecf9f9 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -905,6 +905,11 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
         sd->multi_blk_cnt = 0;
     }
 
+    if (sd_cmd_class[req.cmd] == 6 && FIELD_EX32(sd->ocr, OCR, CARD_CAPACITY)) {
+        /* Only Standard Capacity cards support class 6 commands */
+        return sd_illegal;
+    }
+
     switch (req.cmd) {
     /* Basic commands (Class 0 and Class 1) */
     case 0:	/* CMD0:   GO_IDLE_STATE */
-- 
2.21.3

Re: [PATCH v3 04/11] hw/sd/sdcard: Restrict Class 6 commands to SCSD cards

Posted by Peter Maydell 5 years, 7 months ago

On Fri, 5 Jun 2020 at 11:23, Philippe Mathieu-Daudé <philmd@redhat.com> wrote:
>
> From: Philippe Mathieu-Daudé <f4bug@amsat.org>
>
> Only SCSD cards support Class 6 (Block Oriented Write Protection)
> commands.
>
>   "SD Specifications Part 1 Physical Layer Simplified Spec. v3.01"
>
>   4.3.14 Command Functional Difference in Card Capacity Types
>
>   * Write Protected Group
>
>   SDHC and SDXC do not support write-protected groups. Issuing
>   CMD28, CMD29 and CMD30 generates the ILLEGAL_COMMAND error.
>
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM