media: rkvdec: Improve handling missing short/long term RPS

[PATCH] media: rkvdec: Improve handling missing short/long term RPS

Posted by Detlev Casanova 2 weeks ago

The values of ext_sps_st_rps and ext_sps_lt_rps in struct rkvdec_hevc_run
are not initialized when the respective controls are not set by userspace.

When this is the case, set them to NULL so the rkvdec_hevc_run_preamble
function that parses controls does not access garbage data which leads to
a panic on unaccessible memory.

Fixes: c9a59dc2acc7 ("media: rkvdec: Add HEVC support for the VDPU381 variant")
Reported-by: Christian Hewitt <christianshewitt@gmail.com>
Suggested-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
---
 drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-common.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-common.c b/drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-common.c
index 28267ee30190..3119f3bc9f98 100644
--- a/drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-common.c
+++ b/drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-common.c
@@ -500,11 +500,15 @@ void rkvdec_hevc_run_preamble(struct rkvdec_ctx *ctx,
 		ctrl = v4l2_ctrl_find(&ctx->ctrl_hdl,
 				      V4L2_CID_STATELESS_HEVC_EXT_SPS_ST_RPS);
 		run->ext_sps_st_rps = ctrl ? ctrl->p_cur.p : NULL;
+	} else {
+		run->ext_sps_st_rps = NULL;
 	}
 	if (ctx->has_sps_lt_rps) {
 		ctrl = v4l2_ctrl_find(&ctx->ctrl_hdl,
 				      V4L2_CID_STATELESS_HEVC_EXT_SPS_LT_RPS);
 		run->ext_sps_lt_rps = ctrl ? ctrl->p_cur.p : NULL;
+	} else {
+		run->ext_sps_lt_rps = NULL;
 	}
 
 	rkvdec_run_preamble(ctx, &run->base);
-- 
2.52.0

Re: [PATCH] media: rkvdec: Improve handling missing short/long term RPS

Posted by Nicolas Dufresne 5 hours ago

Le vendredi 23 janvier 2026 à 14:22 -0500, Detlev Casanova a écrit :
> The values of ext_sps_st_rps and ext_sps_lt_rps in struct rkvdec_hevc_run
> are not initialized when the respective controls are not set by userspace.
> 
> When this is the case, set them to NULL so the rkvdec_hevc_run_preamble
> function that parses controls does not access garbage data which leads to
> a panic on unaccessible memory.
> 
> Fixes: c9a59dc2acc7 ("media: rkvdec: Add HEVC support for the VDPU381 variant")
> Reported-by: Christian Hewitt <christianshewitt@gmail.com>
> Suggested-by: Jonas Karlman <jonas@kwiboo.se>
> Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>

Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>

I'll pick this in fixes, so we don't release 6.20 (or 7) with that bug.

cheers,
Nicolas

> ---
>  drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-common.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-common.c b/drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-common.c
> index 28267ee30190..3119f3bc9f98 100644
> --- a/drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-common.c
> +++ b/drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-common.c
> @@ -500,11 +500,15 @@ void rkvdec_hevc_run_preamble(struct rkvdec_ctx *ctx,
>  		ctrl = v4l2_ctrl_find(&ctx->ctrl_hdl,
>  				      V4L2_CID_STATELESS_HEVC_EXT_SPS_ST_RPS);
>  		run->ext_sps_st_rps = ctrl ? ctrl->p_cur.p : NULL;
> +	} else {
> +		run->ext_sps_st_rps = NULL;
>  	}
>  	if (ctx->has_sps_lt_rps) {
>  		ctrl = v4l2_ctrl_find(&ctx->ctrl_hdl,
>  				      V4L2_CID_STATELESS_HEVC_EXT_SPS_LT_RPS);
>  		run->ext_sps_lt_rps = ctrl ? ctrl->p_cur.p : NULL;
> +	} else {
> +		run->ext_sps_lt_rps = NULL;
>  	}
>  
>  	rkvdec_run_preamble(ctx, &run->base);

Re: [PATCH] media: rkvdec: Improve handling missing short/long term RPS

Posted by Christian Hewitt 2 weeks ago

> On Jan 23, 2026, at 11:22 pm, Detlev Casanova <detlev.casanova@collabora.com> wrote:
> 
> The values of ext_sps_st_rps and ext_sps_lt_rps in struct rkvdec_hevc_run
> are not initialized when the respective controls are not set by userspace.
> 
> When this is the case, set them to NULL so the rkvdec_hevc_run_preamble
> function that parses controls does not access garbage data which leads to
> a panic on unaccessible memory.
> 
> Fixes: c9a59dc2acc7 ("media: rkvdec: Add HEVC support for the VDPU381 variant")
> Reported-by: Christian Hewitt <christianshewitt@gmail.com>
> Suggested-by: Jonas Karlman <jonas@kwiboo.se>
> Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>

This solves the sps/rps warnings and occasional kernel splats I’ve been seeing with some HEVC media. Thanks!

Tested-by: Christian Hewitt <christianshewitt@gmail.com>

> ---
> drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-common.c | 4 ++++
> 1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-common.c b/drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-common.c
> index 28267ee30190..3119f3bc9f98 100644
> --- a/drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-common.c
> +++ b/drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-common.c
> @@ -500,11 +500,15 @@ void rkvdec_hevc_run_preamble(struct rkvdec_ctx *ctx,
>        ctrl = v4l2_ctrl_find(&ctx->ctrl_hdl,
>                      V4L2_CID_STATELESS_HEVC_EXT_SPS_ST_RPS);
>        run->ext_sps_st_rps = ctrl ? ctrl->p_cur.p : NULL;
> +    } else {
> +        run->ext_sps_st_rps = NULL;
>    }
>    if (ctx->has_sps_lt_rps) {
>        ctrl = v4l2_ctrl_find(&ctx->ctrl_hdl,
>                      V4L2_CID_STATELESS_HEVC_EXT_SPS_LT_RPS);
>        run->ext_sps_lt_rps = ctrl ? ctrl->p_cur.p : NULL;
> +    } else {
> +        run->ext_sps_lt_rps = NULL;
>    }
> 
>    rkvdec_run_preamble(ctx, &run->base);
> --
> 2.52.0
>