Ignore this. Better patch coming.
Alex
On Tue, Oct 18, 2011 at 3:56 PM, <alexdeucher@xxxxxxxxx> wrote:
> From: Alex Deucher <alexander.deucher@xxxxxxx>
>
> Check access to the fb scratch array to avoid accessing
> memory past the end of the array.
>
> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
> Cc: stable@xxxxxxxxxx
> ---
> drivers/gpu/drm/radeon/atom.c | 15 +++++++++++++--
> drivers/gpu/drm/radeon/atom.h | 1 +
> 2 files changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/atom.c b/drivers/gpu/drm/radeon/atom.c
> index e88c644..f69b852 100644
> --- a/drivers/gpu/drm/radeon/atom.c
> +++ b/drivers/gpu/drm/radeon/atom.c
> @@ -277,7 +277,12 @@ static uint32_t atom_get_src_int(atom_exec_context *ctx, uint8_t attr,
> case ATOM_ARG_FB:
> idx = U8(*ptr);
> (*ptr)++;
> - val = gctx->scratch[((gctx->fb_base + idx) / 4)];
> + if ((gctx->fb_base + idx) > gctx->scratch_size_bytes) {
> + DRM_DEBUG_KMS("ATOM: fb read beyond scratch region: %d vs. %d\n",
> + gctx->fb_base + idx, gctx->scratch_size_bytes);
> + val = 0;
> + } else
> + val = gctx->scratch[((gctx->fb_base + idx) / 4)];
> if (print)
> DEBUG("FB[0x%02X]", idx);
> break;
> @@ -531,7 +536,11 @@ static void atom_put_dst(atom_exec_context *ctx, int arg, uint8_t attr,
> case ATOM_ARG_FB:
> idx = U8(*ptr);
> (*ptr)++;
> - gctx->scratch[((gctx->fb_base + idx) / 4)] = val;
> + if ((gctx->fb_base + idx) > gctx->scratch_size_bytes) {
> + DRM_DEBUG_KMS("ATOM: fb write beyond scratch region: %d vs. %d\n",
> + gctx->fb_base + idx, gctx->scratch_size_bytes);
> + } else
> + gctx->scratch[((gctx->fb_base + idx) / 4)] = val;
> DEBUG("FB[0x%02X]", idx);
> break;
> case ATOM_ARG_PLL:
> @@ -1370,11 +1379,13 @@ int atom_allocate_fb_scratch(struct atom_context *ctx)
>
> usage_bytes = firmware_usage->asFirmwareVramReserveInfo[0].usFirmwareUseInKb * 1024;
> }
> + ctx->scratch_size_bytes = 0;
> if (usage_bytes == 0)
> usage_bytes = 20 * 1024;
> /* allocate some scratch memory */
> ctx->scratch = kzalloc(usage_bytes, GFP_KERNEL);
> if (!ctx->scratch)
> return -ENOMEM;
> + ctx->scratch_size_bytes = usage_bytes;
> return 0;
> }
> diff --git a/drivers/gpu/drm/radeon/atom.h b/drivers/gpu/drm/radeon/atom.h
> index a589a55..93cfe20 100644
> --- a/drivers/gpu/drm/radeon/atom.h
> +++ b/drivers/gpu/drm/radeon/atom.h
> @@ -137,6 +137,7 @@ struct atom_context {
> int cs_equal, cs_above;
> int io_mode;
> uint32_t *scratch;
> + int scratch_size_bytes;
> };
>
> extern int atom_debug;
> --
> 1.7.1.1
>
>
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