[PATCH 6/6] media: amlogic-c3: Add validations for ae and awb config

[Ricardo Ribalda]

Avoid invalid memory access if the zones_num is bigger than
zone_weight.

This patch fixes the following smatch errors:
drivers/media/platform/amlogic/c3/isp/c3-isp-params.c:111 c3_isp_params_awb_wt() error: buffer overflow 'cfg->zone_weight' 768 <= u32max
drivers/media/platform/amlogic/c3/isp/c3-isp-params.c:111 c3_isp_params_awb_wt() error: buffer overflow 'cfg->zone_weight' 768 <= u32max
drivers/media/platform/amlogic/c3/isp/c3-isp-params.c:227 c3_isp_params_ae_wt() error: buffer overflow 'cfg->zone_weight' 255 <= u32max
drivers/media/platform/amlogic/c3/isp/c3-isp-params.c:227 c3_isp_params_ae_wt() error: buffer overflow 'cfg->zone_weight' 255 <= u32max

Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
---
 drivers/media/platform/amlogic/c3/isp/c3-isp-params.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/media/platform/amlogic/c3/isp/c3-isp-params.c b/drivers/media/platform/amlogic/c3/isp/c3-isp-params.c
index 6f9ca7a7dd88..42d780f684d1 100644
--- a/drivers/media/platform/amlogic/c3/isp/c3-isp-params.c
+++ b/drivers/media/platform/amlogic/c3/isp/c3-isp-params.c
@@ -104,6 +104,8 @@ static void c3_isp_params_awb_wt(struct c3_isp_device *isp,
 	c3_isp_write(isp, ISP_AWB_BLK_WT_ADDR, 0);
 
 	zones_num = cfg->horiz_zones_num * cfg->vert_zones_num;
+	if (WARN_ON(zones_num > C3_ISP_AWB_MAX_ZONES))
+		zones_num = C3_ISP_AWB_MAX_ZONES;
 
 	/* Need to write 8 weights at once */
 	for (i = 0; i < zones_num / 8; i++) {
@@ -220,6 +222,8 @@ static void c3_isp_params_ae_wt(struct c3_isp_device *isp,
 	c3_isp_write(isp, ISP_AE_BLK_WT_ADDR, 0);
 
 	zones_num = cfg->horiz_zones_num * cfg->vert_zones_num;
+	if (WARN_ON(zones_num > C3_ISP_AE_MAX_ZONES))
+		zones_num = C3_ISP_AE_MAX_ZONES;
 
 	/* Need to write 8 weights at once */
 	for (i = 0; i < zones_num / 8; i++) {

-- 
2.54.0.545.g6539524ca2-goog