From: Shirish S Date: Tue, 13 Mar 2018 06:25:11 +0000 (+0530) Subject: drm/amd/display: Check msg->size before starting aux transfer X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=2a7b58293dd0f188d27491a8d07b145a9487e172;p=linux.git drm/amd/display: Check msg->size before starting aux transfer This patch adds an essential check related to the size of the payload to be transferred via aux channel. Without this check dal_ddc_service_read_dpcd_data() is fed with inappropriate payload size leading to deadlocks. Signed-off-by: Shirish S Reviewed-by: Harry Wentland Signed-off-by: Alex Deucher --- diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c index 39cfe0fbf1b97..8291d74f26bcf 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c @@ -85,6 +85,9 @@ static ssize_t dm_dp_aux_transfer(struct drm_dp_aux *aux, enum ddc_result res; ssize_t read_bytes; + if (WARN_ON(msg->size > 16)) + return -E2BIG; + switch (msg->request & ~DP_AUX_I2C_MOT) { case DP_AUX_NATIVE_READ: read_bytes = dal_ddc_service_read_dpcd_data(