Re: [PATCH][next] media: venus: hfi,pm,firmware: Fix dereference before null check on hdev

[Muhammad Usama Anjum <musamaanjum@gmail.com>]

On Wed, 2021-04-07 at 15:10 +0100, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> The pointer hdev is being dereferenced twice on the assignment of
> pointers cpu_cs_base and wrapper_base before hdev is being null
> checked.  Fix the potential null pointer dereference issues by
> performing the null check of hdev before dereferencing it when
> assigning cpu_cs_base and wrapper_base.
> 
> Addresses-Coverity: ("Dereference before null check")
> Fixes: ff2a7013b3e6 ("media: venus: hfi,pm,firmware: Convert to block relative addressing")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  drivers/media/platform/qcom/venus/hfi_venus.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/qcom/venus/hfi_venus.c b/drivers/media/platform/qcom/venus/hfi_venus.c
> index cebb20cf371f..3eabb2646572 100644
> --- a/drivers/media/platform/qcom/venus/hfi_venus.c
> +++ b/drivers/media/platform/qcom/venus/hfi_venus.c
> @@ -1094,12 +1094,14 @@ static irqreturn_t venus_isr(struct venus_core *core)
>  {
>  	struct venus_hfi_device *hdev = to_hfi_priv(core);
>  	u32 status;
> -	void __iomem *cpu_cs_base = hdev->core->cpu_cs_base;
> -	void __iomem *wrapper_base = hdev->core->wrapper_base;
> +	void __iomem *cpu_cs_base, *wrapper_base;
>  
>  	if (!hdev)
>  		return IRQ_NONE;
>  
> +	cpu_cs_base = hdev->core->cpu_cs_base;
> +	wrapper_base = hdev->core->wrapper_base;
> +
>  	status = readl(wrapper_base + WRAPPER_INTR_STATUS);
>  	if (IS_V6(core)) {
>  		if (status & WRAPPER_INTR_STATUS_A2H_MASK ||

Reviewed-by: Muhammad Usama Anjum <musamaanjum@gmail.com>