From: Nicholas Kazlauskas <nicholas.kazlaus...@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.stra...@amd.com> Acked-by: Rodrigo Siqueira <rodrigo.sique...@amd.com> Signed-off-by: Nicholas Kazlauskas <nicholas.kazlaus...@amd.com> Tested-by: Daniel Wheeler <daniel.whee...@amd.com> Signed-off-by: Alex Deucher <alexander.deuc...@amd.com> Signed-off-by: Sasha Levin <sas...@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 8e814000db62..5620a3345e4d 100644 --- a/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c +++ b/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c @@ -573,6 +573,11 @@ 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; -- 2.35.1