@@ -527,6 +527,7 @@ static ssize_t ti_sn_aux_transfer(struct drm_dp_aux *aux,
u32 request_val = AUX_CMD_REQ(msg->request);
u8 *buf = msg->buffer;
unsigned int len = msg->size;
+ unsigned int short_len;
unsigned int val;
int ret;
u8 addr_len[SN_AUX_LENGTH_REG + 1 - SN_AUX_ADDR_19_16_REG];
@@ -600,7 +601,8 @@ static ssize_t ti_sn_aux_transfer(struct drm_dp_aux *aux,
}
if (val & AUX_IRQ_STATUS_AUX_SHORT) {
- ret = regmap_read(pdata->regmap, SN_AUX_LENGTH_REG, &len);
+ ret = regmap_read(pdata->regmap, SN_AUX_LENGTH_REG, &short_len);
+ len = min(len, short_len);
if (ret)
goto exit;
} else if (val & AUX_IRQ_STATUS_NAT_I2C_FAIL) {
For aux reads, the value `msg->size` indicates the size of the buffer provided by `msg->buffer`. We should never in any circumstances write more bytes to the buffer since it may overflow the buffer. In the ti-sn65dsi86 driver there is one code path that reads the transfer length from hardware. Even though it's never been seen to be a problem, we should make extra sure that the hardware isn't increasing the length since doing so would cause us to overrun the buffer. Fixes: 982f589bde7a ("drm/bridge: ti-sn65dsi86: Update reply on aux failures") Signed-off-by: Douglas Anderson <dianders@chromium.org> --- drivers/gpu/drm/bridge/ti-sn65dsi86.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)