drm/amdgpu/vkms: fix a possible null pointer dereference

[ Upstream commit cd90511557fdfb394bb4ac4c3b539b007383914c ]

In amdgpu_vkms_conn_get_modes(), the return value of drm_cvt_mode()
is assigned to mode, which will lead to a NULL pointer dereference
on failure of drm_cvt_mode(). Add a check to avoid null pointer
dereference.

Signed-off-by: Ma Ke <make_ruc2021@163.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
index 7148a21..db6fc0c 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
@@ -239,6 +239,8 @@ static int amdgpu_vkms_conn_get_modes(struct drm_connector *connector)
 
        for (i = 0; i < ARRAY_SIZE(common_modes); i++) {
                mode = drm_cvt_mode(dev, common_modes[i].w, common_modes[i].h, 60, false, false, false);
+               if (!mode)
+                       continue;
                drm_mode_probed_add(connector, mode);
        }