Comment 4 for bug 1880822

Avoid OOB access by verifying the requested address belong to
the actual card size. Return ADDRESS_ERROR when not in range.

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

  4.3.4 Data Write

  * Block Write

  Write command is rejected if BLOCK_LEN_ERROR or ADDRESS_ERROR
  occurred and no data transfer is performed.

Fixes: CVE-2020-13253
Reported-by: Alexander Bulekov <email address hidden>
Buglink: https://bugs.launchpad.net/qemu/+bug/1880822
Signed-off-by: Philippe Mathieu-Daudé <email address hidden>
---
Cc: Prasad J Pandit <email address hidden>
---
 hw/sd/sd.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index 3c06a0ac6d..0ced3b5e14 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -1211,6 +1211,10 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
             /* Writing in SPI mode not implemented. */
             if (sd->spi)
                 break;
+ if (addr >= sd->size) {
+ sd->card_status |= ADDRESS_ERROR;
+ return sd_r1;
+ }
             sd->state = sd_receivingdata_state;
             sd->data_start = addr;
             sd->data_offset = 0;
--
2.21.3