drm/omap: handle alloc failures in omap_connector

BugLink: http://bugs.launchpad.net/bugs/1794889
[ Upstream commit 47aaaec818dfd1009d1358974a2931f05dd57203 ]

Handle memory allocation failures in omap_connector to avoid NULL
derefs.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180502091159.7071-5-tomi.valkeinen@ti.com
Reviewed-by: Benoit Parrot <bparrot@ti.com>
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/gpu/drm/omapdrm/omap_connector.c b/drivers/gpu/drm/omapdrm/omap_connector.c
index aa5ba9ae2191c15518ee1aa326165793653912e1..556335ecb2b77b7fb1dc9d2e19bab577d7405176 100644 (file)
--- a/drivers/gpu/drm/omapdrm/omap_connector.c
+++ b/drivers/gpu/drm/omapdrm/omap_connector.c
@@ -123,6 +123,9 @@ static int omap_connector_get_modes(struct drm_connector *connector)
        if (dssdrv->read_edid) {
                void *edid = kzalloc(MAX_EDID, GFP_KERNEL);
 
+               if (!edid)
+                       return 0;
+
                if ((dssdrv->read_edid(dssdev, edid, MAX_EDID) > 0) &&
                                drm_edid_is_valid(edid)) {
                        drm_mode_connector_update_edid_property(
@@ -141,6 +144,9 @@ static int omap_connector_get_modes(struct drm_connector *connector)
                struct drm_display_mode *mode = drm_mode_create(dev);
                struct videomode vm = {0};
 
+               if (!mode)
+                       return 0;
+
                dssdrv->get_timings(dssdev, &vm);
 
                drm_display_mode_from_videomode(&vm, mode);
@@ -196,6 +202,10 @@ static int omap_connector_mode_valid(struct drm_connector *connector,
        if (!r) {
                /* check if vrefresh is still valid */
                new_mode = drm_mode_duplicate(dev, mode);
+
+               if (!new_mode)
+                       return MODE_BAD;
+
                new_mode->clock = vm.pixelclock / 1000;
                new_mode->vrefresh = 0;
                if (mode->vrefresh == drm_mode_vrefresh(new_mode))