[PATCH AUTOSEL 5.15 15/20] drm/amdgpu/vkms: fix a possible null pointer dereference

[Sasha Levin]

From: Ma Ke <make_ruc2021 at 163.com>

[ 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 at 163.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
index 4e8274de8fc0c..083f9c637a82e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
@@ -238,6 +238,8 @@ 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);
 	}
 
-- 
2.42.0