From ab390ab81241cf8bf37c0a0ac2e9c6606bf3e991 Mon Sep 17 00:00:00 2001 From: Qiu-ji Chen Date: Wed, 6 Nov 2024 17:59:06 +0800 Subject: [PATCH] drm/tegra: Fix a possible null pointer dereference commit 780351a5f61416ed2ba1199cc57e4a076fca644d upstream. In tegra_crtc_reset(), new memory is allocated with kzalloc(), but no check is performed. Before calling __drm_atomic_helper_crtc_reset, state should be checked to prevent possible null pointer dereference. Fixes: b7e0b04ae450 ("drm/tegra: Convert to using __drm_atomic_helper_crtc_reset() for reset.") Cc: stable@vger.kernel.org Signed-off-by: Qiu-ji Chen Signed-off-by: Thierry Reding Link: https://lore.kernel.org/r/20241106095906.15247-1-chenqiuji666@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/tegra/dc.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c index 8474f022df8f4..85b4c2cc544f8 100644 --- a/drivers/gpu/drm/tegra/dc.c +++ b/drivers/gpu/drm/tegra/dc.c @@ -1206,7 +1206,10 @@ static void tegra_crtc_reset(struct drm_crtc *crtc) if (crtc->state) tegra_crtc_atomic_destroy_state(crtc, crtc->state); - __drm_atomic_helper_crtc_reset(crtc, &state->base); + if (state) + __drm_atomic_helper_crtc_reset(crtc, &state->base); + else + __drm_atomic_helper_crtc_reset(crtc, NULL); } static struct drm_crtc_state * -- 2.47.3