Subject: FAILED: patch "[PATCH] drm/amd/display: set new_stream to NULL after release" failed to apply to 6.1-stable tree
To: vulab@iscas.ac.cn,alexander.deucher@amd.com,george.zhang@amd.com
Cc: <stable@vger.kernel.org>
From: <gregkh@linuxfoundation.org>
Date: Wed, 29 Jul 2026 14:42:45 +0200
Message-ID: <2026072945-passable-squeegee-1637@gregkh>
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The patch below does not apply to the 6.1-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-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 9fa26b9eed6195bf840f39ac183b9a6237548755
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026072945-passable-squeegee-1637@gregkh' --subject-prefix 'PATCH 6.1.y' 'HEAD^..'

Possible dependencies:


thanks,

greg k-h

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

From 9fa26b9eed6195bf840f39ac183b9a6237548755 Mon Sep 17 00:00:00 2001
From: WenTao Liang <vulab@iscas.ac.cn>
Date: Sun, 28 Jun 2026 15:27:40 +0800
Subject: [PATCH] drm/amd/display: set new_stream to NULL after release

In dm_update_crtc_state(), the skip_modeset path releases new_stream
via dc_stream_release() but does not set the pointer to NULL.

If a later error (e.g., color management failure) triggers the fail
label, the error path calls dc_stream_release() again on the same
dangling pointer, causing a double release and potential use-after-free.

Fix this by setting new_stream to NULL after the initial release.

Fixes: 9b690ef3c704 ("drm/amd/display: Avoid full modeset when not required")
Signed-off-by: WenTao Liang <vulab@iscas.ac.cn>
Reviewed-by: George Zhang <george.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 99f3af19073b3ddbfd96e789124cce12c4277b28)
Cc: stable@vger.kernel.org

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 6210a1ff7cc2..b1e6d735cf02 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -12101,6 +12101,7 @@ static int dm_update_crtc_state(struct amdgpu_display_manager *dm,
 	/* Release extra reference */
 	if (new_stream)
 		dc_stream_release(new_stream);
+	new_stream = NULL;
 
 	/*
 	 * We want to do dc stream updates that do not require a