Re: [PATCH 1/2] media: rockchip: rkcif: fix off by one bugs

[Laurent Pinchart]

On Mon, Feb 16, 2026 at 02:49:56PM +0100, Michael Riesch via B4 Relay wrote:
> From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> 
> Change these comparisons from > vs >= to avoid accessing one element
> beyond the end of the arrays.
> 
> Fixes: 1f2353f5a1af ("media: rockchip: rkcif: add support for rk3568 vicap mipi capture")
> Cc: stable@xxxxxxxxxx
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Reviewed-by: Michael Riesch <michael.riesch@xxxxxxxxxxxxx>
> Signed-off-by: Michael Riesch <michael.riesch@xxxxxxxxxxxxx>
> ---
>  drivers/media/platform/rockchip/rkcif/rkcif-capture-mipi.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/media/platform/rockchip/rkcif/rkcif-capture-mipi.c b/drivers/media/platform/rockchip/rkcif/rkcif-capture-mipi.c
> index 1b81bcc067ef..a933df682acc 100644
> --- a/drivers/media/platform/rockchip/rkcif/rkcif-capture-mipi.c
> +++ b/drivers/media/platform/rockchip/rkcif/rkcif-capture-mipi.c
> @@ -489,8 +489,8 @@ static inline unsigned int rkcif_mipi_get_reg(struct rkcif_interface *interface,
>  
>  	block = interface->index - RKCIF_MIPI_BASE;
>  
> -	if (WARN_ON_ONCE(block > RKCIF_MIPI_MAX - RKCIF_MIPI_BASE) ||
> -	    WARN_ON_ONCE(index > RKCIF_MIPI_REGISTER_MAX))
> +	if (WARN_ON_ONCE(block >= RKCIF_MIPI_MAX - RKCIF_MIPI_BASE) ||
> +	    WARN_ON_ONCE(index >= RKCIF_MIPI_REGISTER_MAX))

While at it, I'd write

	if (WARN_ON_ONCE(block >= ARRAY_SIZE(rkcif->match_data->mipi->blocks)) ||
	    WARN_ON_ONCE(index >= ARRAY_SIZE(rkcif->match_data->mipi->regs)))

Same below.

Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

>  		return RKCIF_REGISTER_NOTSUPPORTED;
>  
>  	offset = rkcif->match_data->mipi->blocks[block].offset;
> @@ -510,9 +510,9 @@ static inline unsigned int rkcif_mipi_id_get_reg(struct rkcif_stream *stream,
>  	block = stream->interface->index - RKCIF_MIPI_BASE;
>  	id = stream->id;
>  
> -	if (WARN_ON_ONCE(block > RKCIF_MIPI_MAX - RKCIF_MIPI_BASE) ||
> -	    WARN_ON_ONCE(id > RKCIF_ID_MAX) ||
> -	    WARN_ON_ONCE(index > RKCIF_MIPI_ID_REGISTER_MAX))
> +	if (WARN_ON_ONCE(block >= RKCIF_MIPI_MAX - RKCIF_MIPI_BASE) ||
> +	    WARN_ON_ONCE(id >= RKCIF_ID_MAX) ||
> +	    WARN_ON_ONCE(index >= RKCIF_MIPI_ID_REGISTER_MAX))
>  		return RKCIF_REGISTER_NOTSUPPORTED;
>  
>  	offset = rkcif->match_data->mipi->blocks[block].offset;

-- 
Regards,

Laurent Pinchart