drm/amdgpu:fix virtual dce bug

BugLink: http://bugs.launchpad.net/bugs/1756978
[ Upstream commit 129d65c18ecfb249aceb540c31fdaf79bd5a11ff ]

this fix the issue that access memory after freed
after driver unloaded.

Signed-off-by: Monk Liu <Monk.Liu@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/dce_virtual.c b/drivers/gpu/drm/amd/amdgpu/dce_virtual.c
index a8829af120c1f713a1ff6b90f27170cce2b72d3a..39460eb1e71a703b98586d7bf31e6badfc1826f0 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/dce_virtual.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_virtual.c
@@ -437,6 +437,8 @@ static int dce_virtual_sw_fini(void *handle)
        drm_kms_helper_poll_fini(adev->ddev);
 
        drm_mode_config_cleanup(adev->ddev);
+       /* clear crtcs pointer to avoid dce irq finish routine access freed data */
+       memset(adev->mode_info.crtcs, 0, sizeof(adev->mode_info.crtcs[0]) * AMDGPU_MAX_CRTCS);
        adev->mode_info.mode_config_initialized = false;
        return 0;
 }
@@ -723,7 +725,7 @@ static void dce_virtual_set_crtc_vblank_interrupt_state(struct amdgpu_device *ad
                                                        int crtc,
                                                        enum amdgpu_interrupt_state state)
 {
-       if (crtc >= adev->mode_info.num_crtc) {
+       if (crtc >= adev->mode_info.num_crtc || !adev->mode_info.crtcs[crtc]) {
                DRM_DEBUG("invalid crtc %d\n", crtc);
                return;
        }