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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