[Why] Similar to commit<dddc0557e>("drm/amd/display: Guard against null crtc in CRC IRQ"), a null pointer deference can occur if crtc is null in dm_set_vblank.

[How]

Check that CRTC is non-null before accessing its fields.

Signed-off-by: Defang Bo bodefang@126.com --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index e2b23486..df23d28 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -4875,10 +4875,17 @@ static inline int dm_set_vupdate_irq(struct drm_crtc *crtc, bool enable) static inline int dm_set_vblank(struct drm_crtc *crtc, bool enable) { enum dc_irq_source irq_source; - struct amdgpu_crtc *acrtc = to_amdgpu_crtc(crtc); - struct amdgpu_device *adev = drm_to_adev(crtc->dev); - struct dm_crtc_state *acrtc_state = to_dm_crtc_state(crtc->state); + struct amdgpu_crtc *acrtc; + struct amdgpu_device *adev; + struct dm_crtc_state *acrtc_state; int rc = 0; + + if (crtc == NULL) + return rc; + + acrtc = to_amdgpu_crtc(crtc); + adev = drm_to_adev(crtc->dev); + acrtc_state = to_dm_crtc_state(crtc->state);

if (enable) { /* vblank irq on -> Only need vupdate irq in vrr mode */