From 5fe89a6acd668cbd1817fcdef5caa9fee568c2e8 Mon Sep 17 00:00:00 2001 From: Sean Paul Date: Tue, 14 Apr 2020 15:02:55 -0400 Subject: [PATCH] drm: Fix HDCP failures when SRM fw is missing The SRM cleanup in 79643fddd6eb2 ("drm/hdcp: optimizing the srm handling") inadvertently altered the behavior of HDCP auth when the SRM firmware is missing. Before that patch, missing SRM was interpreted as the device having no revoked keys. With that patch, if the SRM fw file is missing we reject _all_ keys. This patch fixes that regression by returning success if the file cannot be found. It also checks the return value from request_srm such that we won't end up trying to parse the ksv list if there is an error fetching it. Fixes: 79643fddd6eb ("drm/hdcp: optimizing the srm handling") Cc: stable@vger.kernel.org Cc: Ramalingam C Cc: Sean Paul Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Thomas Zimmermann Cc: David Airlie Cc: Daniel Vetter Cc: dri-devel@lists.freedesktop.org Reviewed-by: Ramalingam C Signed-off-by: Sean Paul Link: https://patchwork.freedesktop.org/patch/msgid/20200414190258.38873-1-sean@poorly.run Changes in v2: -Noticed a couple other things to clean up Reviewed-by: Ramalingam C --- drivers/gpu/drm/drm_hdcp.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_hdcp.c b/drivers/gpu/drm/drm_hdcp.c index 7f386adcf872..910108ccaae1 100644 --- a/drivers/gpu/drm/drm_hdcp.c +++ b/drivers/gpu/drm/drm_hdcp.c @@ -241,8 +241,12 @@ static int drm_hdcp_request_srm(struct drm_device *drm_dev, ret = request_firmware_direct(&fw, (const char *)fw_name, drm_dev->dev); - if (ret < 0) + if (ret < 0) { + *revoked_ksv_cnt = 0; + *revoked_ksv_list = NULL; + ret = 0; goto exit; + } if (fw->size && fw->data) ret = drm_hdcp_srm_update(fw->data, fw->size, revoked_ksv_list, @@ -287,6 +291,8 @@ int drm_hdcp_check_ksvs_revoked(struct drm_device *drm_dev, u8 *ksvs, ret = drm_hdcp_request_srm(drm_dev, &revoked_ksv_list, &revoked_ksv_cnt); + if (ret) + return ret; /* revoked_ksv_cnt will be zero when above function failed */ for (i = 0; i < revoked_ksv_cnt; i++)