FAILED: patch "[PATCH] drm/sti: avoid potential dereference of error pointers" failed to apply to 5.4-stable tree

FAILED: patch "[PATCH] drm/sti: avoid potential dereference of error pointers" 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 831214f77037de02afc287eae93ce97f218d8c04
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2024120622-footsore-silo-9e55@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From 831214f77037de02afc287eae93ce97f218d8c04 Mon Sep 17 00:00:00 2001
From: Ma Ke <make24@iscas.ac.cn>
Date: Fri, 13 Sep 2024 17:04:12 +0800
Subject: [PATCH] drm/sti: avoid potential dereference of error pointers

The return value of drm_atomic_get_crtc_state() needs to be
checked. To avoid use of error pointer 'crtc_state' in case
of the failure.

Cc: stable@vger.kernel.org
Fixes: dd86dc2f9ae1 ("drm/sti: implement atomic_check for the planes")
Signed-off-by: Ma Ke <make24@iscas.ac.cn>
Link: https://patchwork.freedesktop.org/patch/msgid/20240913090412.2022848-1-make24@iscas.ac.cn
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>

diff --git a/drivers/gpu/drm/sti/sti_cursor.c b/drivers/gpu/drm/sti/sti_cursor.c
index db0a1eb53532..c59fcb4dca32 100644
--- a/drivers/gpu/drm/sti/sti_cursor.c
+++ b/drivers/gpu/drm/sti/sti_cursor.c
@@ -200,6 +200,9 @@ static int sti_cursor_atomic_check(struct drm_plane *drm_plane,
 		return 0;
 
 	crtc_state = drm_atomic_get_crtc_state(state, crtc);
+	if (IS_ERR(crtc_state))
+		return PTR_ERR(crtc_state);
+
 	mode = &crtc_state->mode;
 	dst_x = new_plane_state->crtc_x;
 	dst_y = new_plane_state->crtc_y;