[PATCH 10/10] drm/amd/display: handle failed allocation during stream construction - Linux-stable-mirror

10 Jul 2020

From: Josip Pavic Josip.Pavic@amd.com
[Why]
Failing to allocate a transfer function during stream construction leads
to a null pointer dereference
[How]
Handle the failed allocation by failing the stream construction
Cc: stable@vger.kernel.org
Signed-off-by: Josip Pavic Josip.Pavic@amd.com
Reviewed-by: Aric Cyr Aric.Cyr@amd.com
Acked-by: Rodrigo Siqueira Rodrigo.Siqueira@amd.com
---
 .../gpu/drm/amd/display/dc/core/dc_stream.c   | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
index 3b897372ed27..d6989d115c5c 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
@@ -56,7 +56,7 @@ void update_stream_signal(struct dc_stream_state *stream, struct dc_sink *sink)
    }
 }
-static void dc_stream_construct(struct dc_stream_state *stream,
+static bool dc_stream_construct(struct dc_stream_state *stream,
    struct dc_sink *dc_sink_data)
 {
    uint32_t i = 0;
@@ -118,11 +118,17 @@ static void dc_stream_construct(struct dc_stream_state *stream,
    update_stream_signal(stream, dc_sink_data);
stream->out_transfer_func = dc_create_transfer_func();
+	if (stream->out_transfer_func == NULL) {
+		dc_sink_release(dc_sink_data);
+		return false;
+	}
    stream->out_transfer_func->type = TF_TYPE_BYPASS;
    stream->out_transfer_func->ctx = stream->ctx;
stream->stream_id = stream->ctx->dc_stream_id_count;
    stream->ctx->dc_stream_id_count++;
+
+	return true;
 }
static void dc_stream_destruct(struct dc_stream_state *stream)
@@ -164,13 +170,20 @@ struct dc_stream_state *dc_create_stream_for_sink(
stream = kzalloc(sizeof(struct dc_stream_state), GFP_KERNEL);
    if (stream == NULL)
-		return NULL;
+		goto alloc_fail;
-	dc_stream_construct(stream, sink);
+	if (dc_stream_construct(stream, sink) == false)
+		goto construct_fail;
kref_init(&stream->refcount);
return stream;
+
+construct_fail:
+	kfree(stream);
+
+alloc_fail:
+	return NULL;
 }
struct dc_stream_state *dc_copy_stream(const struct dc_stream_state *stream)
-- 
2.27.0


    