@@ -1167,13 +1167,15 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
case 17: /* CMD17: READ_SINGLE_BLOCK */
switch (sd->state) {
case sd_transfer_state:
- sd->state = sd_sendingdata_state;
- sd->data_start = addr;
- sd->data_offset = 0;
if (sd->data_start + sd->blk_len > sd->size) {
sd->card_status |= ADDRESS_ERROR;
+ return sd_r1;
}
+
+ sd->state = sd_sendingdata_state;
+ sd->data_start = addr;
+ sd->data_offset = 0;
return sd_r1;
default:
@@ -1184,13 +1186,15 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
case 18: /* CMD18: READ_MULTIPLE_BLOCK */
switch (sd->state) {
case sd_transfer_state:
- sd->state = sd_sendingdata_state;
- sd->data_start = addr;
- sd->data_offset = 0;
if (sd->data_start + sd->blk_len > sd->size) {
sd->card_status |= ADDRESS_ERROR;
+ return sd_r1;
}
+
+ sd->state = sd_sendingdata_state;
+ sd->data_start = addr;
+ sd->data_offset = 0;
return sd_r1;
default:
@@ -1230,14 +1234,17 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
/* Writing in SPI mode not implemented. */
if (sd->spi)
break;
+
+ if (sd->data_start + sd->blk_len > sd->size) {
+ sd->card_status |= ADDRESS_ERROR;
+ return sd_r1;
+ }
+
sd->state = sd_receivingdata_state;
sd->data_start = addr;
sd->data_offset = 0;
sd->blk_written = 0;
- if (sd->data_start + sd->blk_len > sd->size) {
- sd->card_status |= ADDRESS_ERROR;
- }
if (sd_wp_addr(sd, sd->data_start)) {
sd->card_status |= WP_VIOLATION;
}
@@ -1257,14 +1264,17 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
/* Writing in SPI mode not implemented. */
if (sd->spi)
break;
+
+ if (sd->data_start + sd->blk_len > sd->size) {
+ sd->card_status |= ADDRESS_ERROR;
+ return sd_r1;
+ }
+
sd->state = sd_receivingdata_state;
sd->data_start = addr;
sd->data_offset = 0;
sd->blk_written = 0;
- if (sd->data_start + sd->blk_len > sd->size) {
- sd->card_status |= ADDRESS_ERROR;
- }
if (sd_wp_addr(sd, sd->data_start)) {
sd->card_status |= WP_VIOLATION;
}
Only move the state machine to ReceivingData if there is no pending error. This avoids later OOB access while processing commands queued. "SD Specifications Part 1 Physical Layer Simplified Spec. v3.01" 4.3.3 Data Read Read command is rejected if BLOCK_LEN_ERROR or ADDRESS_ERROR occurred and no data transfer is performed. 4.3.4 Data Write Write command is rejected if BLOCK_LEN_ERROR or ADDRESS_ERROR occurred and no data transfer is performed. WP_VIOLATION errors are not modified: the error bit is set, we stay in receive-data state, wait for a stop command. All further data transfer is ignored. See the check on sd->card_status at the beginning of sd_read_data() and sd_write_data(). Fixes: CVE-2020-13253 Cc: Prasad J Pandit <pjp@fedoraproject.org> Reported-by: Alexander Bulekov <alxndr@bu.edu> Buglink: https://bugs.launchpad.net/qemu/+bug/1880822 Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> --- v4: Only modify ADDRESS_ERROR, not WP_VIOLATION (pm215) --- hw/sd/sd.c | 34 ++++++++++++++++++++++------------ 1 file changed, 22 insertions(+), 12 deletions(-)