FAILED: patch "[PATCH] ALSA: hda: cs35l41: Fix NULL pointer dereference in" failed to apply to 6.6-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 6.6-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-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x c34b04cc6178f33c08331568c7fd25c5b9a39f66
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025121643-crust-motocross-9384@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From c34b04cc6178f33c08331568c7fd25c5b9a39f66 Mon Sep 17 00:00:00 2001
From: Denis Arefev <arefev@swemel.ru>
Date: Tue, 2 Dec 2025 13:13:36 +0300
Subject: [PATCH] ALSA: hda: cs35l41: Fix NULL pointer dereference in
 cs35l41_hda_read_acpi()

The acpi_get_first_physical_node() function can return NULL, in which
case the get_device() function also returns NULL, but this value is
then dereferenced without checking,so add a check to prevent a crash.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 7b2f3eb492da ("ALSA: hda: cs35l41: Add support for CS35L41 in HDA systems")
Cc: stable@vger.kernel.org
Signed-off-by: Denis Arefev <arefev@swemel.ru>
Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20251202101338.11437-1-arefev@swemel.ru

diff --git a/sound/hda/codecs/side-codecs/cs35l41_hda.c b/sound/hda/codecs/side-codecs/cs35l41_hda.c
index c0f2a3ff77a1..21e00055c0c4 100644
--- a/sound/hda/codecs/side-codecs/cs35l41_hda.c
+++ b/sound/hda/codecs/side-codecs/cs35l41_hda.c
@@ -1901,6 +1901,8 @@ static int cs35l41_hda_read_acpi(struct cs35l41_hda *cs35l41, const char *hid, i
 
 	cs35l41->dacpi = adev;
 	physdev = get_device(acpi_get_first_physical_node(adev));
+	if (!physdev)
+		return -ENODEV;
 
 	sub = acpi_get_subsystem_id(ACPI_HANDLE(physdev));
 	if (IS_ERR(sub))