[PATCH 1/4] drm/radeon: make VCE handle check more strict

Alex Deucher alexdeucher at gmail.com
Thu May 7 09:29:58 PDT 2015


On Thu, May 7, 2015 at 9:19 AM, Christian König <deathsimple at vodafone.de> wrote:
> From: Christian König <christian.koenig at amd.com>
>
> Invalid handles can crash the hw.
>
> Signed-off-by: Christian König <christian.koenig at amd.com>
> CC: stable at vger.kernel.org

Applied the series to my -fixes tree.

Alex

> ---
>  drivers/gpu/drm/radeon/radeon_vce.c | 65 +++++++++++++++++++++++++++----------
>  1 file changed, 48 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_vce.c b/drivers/gpu/drm/radeon/radeon_vce.c
> index 24f849f..0de5711 100644
> --- a/drivers/gpu/drm/radeon/radeon_vce.c
> +++ b/drivers/gpu/drm/radeon/radeon_vce.c
> @@ -493,18 +493,27 @@ int radeon_vce_cs_reloc(struct radeon_cs_parser *p, int lo, int hi,
>   *
>   * @p: parser context
>   * @handle: handle to validate
> + * @allocated: allocated a new handle?
>   *
>   * Validates the handle and return the found session index or -EINVAL
>   * we we don't have another free session index.
>   */
> -int radeon_vce_validate_handle(struct radeon_cs_parser *p, uint32_t handle)
> +static int radeon_vce_validate_handle(struct radeon_cs_parser *p,
> +                                     uint32_t handle, bool *allocated)
>  {
>         unsigned i;
>
> +       *allocated = false;
> +
>         /* validate the handle */
>         for (i = 0; i < RADEON_MAX_VCE_HANDLES; ++i) {
> -               if (atomic_read(&p->rdev->vce.handles[i]) == handle)
> +               if (atomic_read(&p->rdev->vce.handles[i]) == handle) {
> +                       if (p->rdev->vce.filp[i] != p->filp) {
> +                               DRM_ERROR("VCE handle collision detected!\n");
> +                               return -EINVAL;
> +                       }
>                         return i;
> +               }
>         }
>
>         /* handle not found try to alloc a new one */
> @@ -512,6 +521,7 @@ int radeon_vce_validate_handle(struct radeon_cs_parser *p, uint32_t handle)
>                 if (!atomic_cmpxchg(&p->rdev->vce.handles[i], 0, handle)) {
>                         p->rdev->vce.filp[i] = p->filp;
>                         p->rdev->vce.img_size[i] = 0;
> +                       *allocated = true;
>                         return i;
>                 }
>         }
> @@ -529,10 +539,10 @@ int radeon_vce_validate_handle(struct radeon_cs_parser *p, uint32_t handle)
>  int radeon_vce_cs_parse(struct radeon_cs_parser *p)
>  {
>         int session_idx = -1;
> -       bool destroyed = false;
> +       bool destroyed = false, created = false, allocated = false;
>         uint32_t tmp, handle = 0;
>         uint32_t *size = &tmp;
> -       int i, r;
> +       int i, r = 0;
>
>         while (p->idx < p->chunk_ib->length_dw) {
>                 uint32_t len = radeon_get_ib_value(p, p->idx);
> @@ -540,18 +550,21 @@ int radeon_vce_cs_parse(struct radeon_cs_parser *p)
>
>                 if ((len < 8) || (len & 3)) {
>                         DRM_ERROR("invalid VCE command length (%d)!\n", len);
> -                       return -EINVAL;
> +                       r = -EINVAL;
> +                       goto out;
>                 }
>
>                 if (destroyed) {
>                         DRM_ERROR("No other command allowed after destroy!\n");
> -                       return -EINVAL;
> +                       r = -EINVAL;
> +                       goto out;
>                 }
>
>                 switch (cmd) {
>                 case 0x00000001: // session
>                         handle = radeon_get_ib_value(p, p->idx + 2);
> -                       session_idx = radeon_vce_validate_handle(p, handle);
> +                       session_idx = radeon_vce_validate_handle(p, handle,
> +                                                                &allocated);
>                         if (session_idx < 0)
>                                 return session_idx;
>                         size = &p->rdev->vce.img_size[session_idx];
> @@ -561,6 +574,13 @@ int radeon_vce_cs_parse(struct radeon_cs_parser *p)
>                         break;
>
>                 case 0x01000001: // create
> +                       created = true;
> +                       if (!allocated) {
> +                               DRM_ERROR("Handle already in use!\n");
> +                               r = -EINVAL;
> +                               goto out;
> +                       }
> +
>                         *size = radeon_get_ib_value(p, p->idx + 8) *
>                                 radeon_get_ib_value(p, p->idx + 10) *
>                                 8 * 3 / 2;
> @@ -578,12 +598,12 @@ int radeon_vce_cs_parse(struct radeon_cs_parser *p)
>                         r = radeon_vce_cs_reloc(p, p->idx + 10, p->idx + 9,
>                                                 *size);
>                         if (r)
> -                               return r;
> +                               goto out;
>
>                         r = radeon_vce_cs_reloc(p, p->idx + 12, p->idx + 11,
>                                                 *size / 3);
>                         if (r)
> -                               return r;
> +                               goto out;
>                         break;
>
>                 case 0x02000001: // destroy
> @@ -594,7 +614,7 @@ int radeon_vce_cs_parse(struct radeon_cs_parser *p)
>                         r = radeon_vce_cs_reloc(p, p->idx + 3, p->idx + 2,
>                                                 *size * 2);
>                         if (r)
> -                               return r;
> +                               goto out;
>                         break;
>
>                 case 0x05000004: // video bitstream buffer
> @@ -602,36 +622,47 @@ int radeon_vce_cs_parse(struct radeon_cs_parser *p)
>                         r = radeon_vce_cs_reloc(p, p->idx + 3, p->idx + 2,
>                                                 tmp);
>                         if (r)
> -                               return r;
> +                               goto out;
>                         break;
>
>                 case 0x05000005: // feedback buffer
>                         r = radeon_vce_cs_reloc(p, p->idx + 3, p->idx + 2,
>                                                 4096);
>                         if (r)
> -                               return r;
> +                               goto out;
>                         break;
>
>                 default:
>                         DRM_ERROR("invalid VCE command (0x%x)!\n", cmd);
> -                       return -EINVAL;
> +                       r = -EINVAL;
> +                       goto out;
>                 }
>
>                 if (session_idx == -1) {
>                         DRM_ERROR("no session command at start of IB\n");
> -                       return -EINVAL;
> +                       r = -EINVAL;
> +                       goto out;
>                 }
>
>                 p->idx += len / 4;
>         }
>
> -       if (destroyed) {
> -               /* IB contains a destroy msg, free the handle */
> +       if (allocated && !created) {
> +               DRM_ERROR("New session without create command!\n");
> +               r = -ENOENT;
> +       }
> +
> +out:
> +       if ((!r && destroyed) || (r && allocated)) {
> +               /*
> +                * IB contains a destroy msg or we have allocated an
> +                * handle and got an error, anyway free the handle
> +                */
>                 for (i = 0; i < RADEON_MAX_VCE_HANDLES; ++i)
>                         atomic_cmpxchg(&p->rdev->vce.handles[i], handle, 0);
>         }
>
> -       return 0;
> +       return r;
>  }
>
>  /**
> --
> 1.9.1
>


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