Re: [PATCH v2] media: qcom: camss: vfe: Fix out-of-bounds access in vfe_isr_reg_update()

[Bryan O'Donoghue <bryan.odonoghue@linaro.org>]

On 29/12/2025 07:52, Alper Ak wrote:
> vfe_isr() iterates using MSM_VFE_IMAGE_MASTERS_NUM(7) as the loop
> bound and passes the index to vfe_isr_reg_update(). However,
> vfe->line[] array is defined with VFE_LINE_NUM_MAX(4):
> 
>      struct vfe_line line[VFE_LINE_NUM_MAX];
> 
> When index is 4, 5, 6, the access to vfe->line[line_id] exceeds
> the array bounds and resulting in out-of-bounds memory access.
> 
> Fix this by using separate loops for output lines and write masters.
> 
> Fixes: 4edc8eae715c ("media: camss: Add initial support for VFE hardware version Titan 480")
> Signed-off-by: Alper Ak <alperyasinak1@gmail.com>
> ---
>   drivers/media/platform/qcom/camss/camss-vfe-480.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/qcom/camss/camss-vfe-480.c b/drivers/media/platform/qcom/camss/camss-vfe-480.c
> index 4feea590a47b..d73f733fde04 100644
> --- a/drivers/media/platform/qcom/camss/camss-vfe-480.c
> +++ b/drivers/media/platform/qcom/camss/camss-vfe-480.c
> @@ -202,11 +202,13 @@ static irqreturn_t vfe_isr(int irq, void *dev)
>   		writel_relaxed(status, vfe->base + VFE_BUS_IRQ_CLEAR(0));
>   		writel_relaxed(1, vfe->base + VFE_BUS_IRQ_CLEAR_GLOBAL);
>   
> -		/* Loop through all WMs IRQs */
> -		for (i = 0; i < MSM_VFE_IMAGE_MASTERS_NUM; i++) {
> +		for (i = 0; i < MAX_VFE_OUTPUT_LINES; i++) {
>   			if (status & BUS_IRQ_MASK_0_RDI_RUP(vfe, i))
>   				vfe_isr_reg_update(vfe, i);
> +		}
>   
> +		/* Loop through all WMs IRQs */
> +		for (i = 0; i < MSM_VFE_IMAGE_MASTERS_NUM; i++) {
>   			if (status & BUS_IRQ_MASK_0_COMP_DONE(vfe, RDI_COMP_GROUP(i)))
>   				vfe_buf_done(vfe, i);
>   		}

LGTM - assuming hardware tests pass.

Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>

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