From: Nicholas Kazlauskas nicholas.kazlauskas@amd.com
[ Upstream commit bc19909f19fdc8253d720d11c948935786fbfa08 ]
[Why] In the case where we don't support DMUB aux but we have DPIA links in the configuration we might try to message AUX using the legacy path - where DDC pin is NULL. This causes a NULL pointer dereference.
[How] Guard against NULL DDC pin, return a failure for aux engine acquire.
Reviewed-by: Michael Strauss Michael.Strauss@amd.com Acked-by: Rodrigo Siqueira Rodrigo.Siqueira@amd.com Signed-off-by: Nicholas Kazlauskas nicholas.kazlauskas@amd.com Tested-by: Daniel Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/display/dc/dce/dce_aux.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c b/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c index 3c3347341103..ae9c0df1a844 100644 --- a/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c +++ b/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c @@ -563,6 +563,11 @@ int dce_aux_transfer_raw(struct ddc_service *ddc, memset(&aux_req, 0, sizeof(aux_req)); memset(&aux_rep, 0, sizeof(aux_rep));
+ if (ddc_pin == NULL) { + *operation_result = AUX_RET_ERROR_ENGINE_ACQUIRE; + return -1; + } + aux_engine = ddc->ctx->dc->res_pool->engines[ddc_pin->pin_data->en]; if (!acquire(aux_engine, ddc_pin)) { *operation_result = AUX_RET_ERROR_ENGINE_ACQUIRE;