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Re: [PATCH] [media] s3c-camif: fix out-of-bounds array access




On 09/13/2017 04:03 PM, Arnd Bergmann wrote:
On Wed, Sep 13, 2017 at 11:25 AM, Sylwester Nawrocki
<s.nawrocki@xxxxxxxxxxx>  wrote:
On 09/12/2017 10:09 PM, Arnd Bergmann wrote:
   {
       const struct s3c_camif_variant *variant = camif->variant;
       const struct vp_pix_limits *pix_lim;
-     int i = ARRAY_SIZE(camif_mbus_formats);

       /* FIXME: constraints against codec or preview path ? */
       pix_lim = &variant->vp_pix_limits[VP_CODEC];

-     while (i-- >= 0)
-             if (camif_mbus_formats[i] == mf->code)
-                     break;
-
-     mf->code = camif_mbus_formats[i];

Interesting finding... the function needs to ensure mf->code is set
to one of supported values by the driver, so instead of removing
how about changing the above line to:

         if (i < 0)
                 mf->code = camif_mbus_formats[0];

?
That would still have one of the two out-of-bounds accesses;-)

Ah, indeed :/

maybe this

for (i = 0; i < ARRAY_SIZE(camif_mbus_formats); i++)
         if (camif_mbus_formats[i] == mf->code)
                break;

if (i == ARRAY_SIZE(camif_mbus_formats))
        mf->code = camif_mbus_formats[0];

Yes, it should work that way.

--
Thanks,
Sylwester