FAILED: patch "[PATCH] drm/tegra: Fix a possible null pointer dereference" failed to apply to 5.4-stable tree

FAILED: patch "[PATCH] drm/tegra: Fix a possible null pointer dereference" failed to apply to 5.4-stable tree

[gregkh]

The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x 780351a5f61416ed2ba1199cc57e4a076fca644d
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025063053-vastness-consuming-8fce@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 780351a5f61416ed2ba1199cc57e4a076fca644d Mon Sep 17 00:00:00 2001
From: Qiu-ji Chen <chenqiuji666@gmail.com>
Date: Wed, 6 Nov 2024 17:59:06 +0800
Subject: [PATCH] drm/tegra: Fix a possible null pointer dereference

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 <chenqiuji666@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20241106095906.15247-1-chenqiuji666@gmail.com

diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
index 56f12dbcee3e..59d5c1ba145a 100644
--- a/drivers/gpu/drm/tegra/dc.c
+++ b/drivers/gpu/drm/tegra/dc.c
@@ -1393,7 +1393,10 @@ 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 *