[PATCH] media: verisilicon: Fix null pointer dereference in try_fmt

[Nicolas Dufresne]

Hi Diederik,

Le mardi 23 mai 2023 à 16:22 +0200, Diederik de Haas a écrit :
> On Tuesday, 16 May 2023 11:12:09 CEST Michael Tretter wrote:
> > Since commit db6f68b51e5c ("media: verisilicon: Do not set context
> > src/dst formats in reset functions"), vpu_src_fmt is not set in the
> > reset function, but only set in hantro_set_fmt_out, which calls
> > hantro_try_fmt before setting the format. Therefore, hantro_try_fmt
> > might be called with vpu_src_fmt still being null.
> > 
> > Add a test if the format is actually set before checking the format.
> > 
> > Signed-off-by: Michael Tretter <m.tretter at pengutronix.de>
> > Fixes: db6f68b51e5c ("media: verisilicon: Do not set context src/dst formats
> > in reset functions") ---
> >  drivers/media/platform/verisilicon/hantro_v4l2.c | 9 ++++++---
> >  1 file changed, 6 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/media/platform/verisilicon/hantro_v4l2.c
> > b/drivers/media/platform/verisilicon/hantro_v4l2.c index
> > 835518534e3b..ec37d2646fde 100644
> > --- a/drivers/media/platform/verisilicon/hantro_v4l2.c
> > +++ b/drivers/media/platform/verisilicon/hantro_v4l2.c
> > @@ -313,17 +313,20 @@ static int hantro_try_fmt(const struct hantro_ctx
> > *ctx, /* Fill remaining fields */
> >  		v4l2_fill_pixfmt_mp(pix_mp, fmt->fourcc, pix_mp->width,
> >  				    pix_mp->height);
> > -		if (ctx->vpu_src_fmt->fourcc == V4L2_PIX_FMT_H264_SLICE 
> &&
> > +		if (ctx->vpu_src_fmt &&
> > +		    ctx->vpu_src_fmt->fourcc == V4L2_PIX_FMT_H264_SLICE 
> &&
> >  		    !hantro_needs_postproc(ctx, fmt))
> >  			pix_mp->plane_fmt[0].sizeimage +=
> >  				hantro_h264_mv_size(pix_mp-
> > width,
> >  						    pix_mp-
> > height);
> > -		else if (ctx->vpu_src_fmt->fourcc == 
> V4L2_PIX_FMT_VP9_FRAME &&
> > +		else if (ctx->vpu_src_fmt &&
> > +			 ctx->vpu_src_fmt->fourcc == 
> V4L2_PIX_FMT_VP9_FRAME &&
> >  			 !hantro_needs_postproc(ctx, fmt))
> >  			pix_mp->plane_fmt[0].sizeimage +=
> >  				hantro_vp9_mv_size(pix_mp->width,
> >  						   pix_mp-
> > height);
> > -		else if (ctx->vpu_src_fmt->fourcc == 
> V4L2_PIX_FMT_HEVC_SLICE &&
> > +		else if (ctx->vpu_src_fmt &&
> > +			 ctx->vpu_src_fmt->fourcc == 
> V4L2_PIX_FMT_HEVC_SLICE &&
> >  			 !hantro_needs_postproc(ctx, fmt))
> >  			pix_mp->plane_fmt[0].sizeimage +=
> >  				hantro_hevc_mv_size(pix_mp-
> > width,
> 
> I have verified that this patch fixes the crash I was seeing since 6.4.
> https://lore.kernel.org/linux-media/12724349.O9o76ZdvQC@bagend/ is a/the other 
> patch which also fixed the crash.

An official form of this comment would be Tested-by: <name> <email>, would you
agree to have this added ?

Nicolas