drm/msm/dpu: invalid parameter check in dpu_setup_dspp_pcc

BugLink: https://bugs.launchpad.net/bugs/1959879
[ Upstream commit 170b22234d5495f5e0844246e23f004639ee89ba ]

The function performs a check on the "ctx" input parameter, however, it
is used before the check.

Initialize the "base" variable after the sanity check to avoid a
possible NULL pointer dereference.

Fixes: 4259ff7ae509e ("drm/msm/dpu: add support for pcc color block in dpu driver")
Addresses-Coverity-ID: 1493866 ("Null pointer dereference")
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Link: https://lore.kernel.org/r/20220109192431.135949-1-jose.exposito89@gmail.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dspp.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dspp.c
index a98e964c3b6fa6941691dbf0ed81fa52378b5713..355894a3b48c376612e2491bbbb5f88b8be3eb4e 100644 (file)
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dspp.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dspp.c
@@ -26,9 +26,16 @@ static void dpu_setup_dspp_pcc(struct dpu_hw_dspp *ctx,
                struct dpu_hw_pcc_cfg *cfg)
 {
 
-       u32 base = ctx->cap->sblk->pcc.base;
+       u32 base;
 
-       if (!ctx || !base) {
+       if (!ctx) {
+               DRM_ERROR("invalid ctx %pK\n", ctx);
+               return;
+       }
+
+       base = ctx->cap->sblk->pcc.base;
+
+       if (!base) {
                DRM_ERROR("invalid ctx %pK pcc base 0x%x\n", ctx, base);
                return;
        }