diff options
| author | Philippe Mathieu-Daudé <f4bug@amsat.org> | 2020-06-04 19:22:29 +0200 |
|---|---|---|
| committer | Philippe Mathieu-Daudé <f4bug@amsat.org> | 2020-07-14 15:46:14 +0200 |
| commit | 790762e5487114341cccc5bffcec4cb3c022c3cd (patch) | |
| tree | 62e54ca5955eaa4c0d2d41ff474becd6babe0060 /hw | |
| parent | 794d68de2f021a6d3874df41d6bbe8590ec05207 (diff) | |
hw/sd/sdcard: Do not switch to ReceivingData if address is invalid
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: qemu-stable@nongnu.org
Reported-by: Alexander Bulekov <alxndr@bu.edu>
Buglink: https://bugs.launchpad.net/qemu/+bug/1880822
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20200630133912.9428-6-f4bug@amsat.org>
Diffstat (limited to 'hw')
| -rw-r--r-- | hw/sd/sd.c | 38 |
1 files changed, 24 insertions, 14 deletions
diff --git a/hw/sd/sd.c b/hw/sd/sd.c index f4f76f8fd2..fad9cf1ee7 100644 --- a/hw/sd/sd.c +++ b/hw/sd/sd.c @@ -1171,13 +1171,15 @@ 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) { + if (addr + 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: @@ -1188,13 +1190,15 @@ 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) { + if (addr + 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: @@ -1234,14 +1238,17 @@ 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->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; } @@ -1261,14 +1268,17 @@ 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->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; } |