FAILED: patch "[PATCH] net: rfkill: gpio: Fix crash due to dereferencering" failed to apply to 5.10-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.10-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-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x b6f56a44e4c1014b08859dcf04ed246500e310e5
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025092156-postal-sappiness-e1ac@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From b6f56a44e4c1014b08859dcf04ed246500e310e5 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hansg@kernel.org>
Date: Sat, 13 Sep 2025 13:35:15 +0200
Subject: [PATCH] net: rfkill: gpio: Fix crash due to dereferencering
 uninitialized pointer

Since commit 7d5e9737efda ("net: rfkill: gpio: get the name and type from
device property") rfkill_find_type() gets called with the possibly
uninitialized "const char *type_name;" local variable.

On x86 systems when rfkill-gpio binds to a "BCM4752" or "LNV4752"
acpi_device, the rfkill->type is set based on the ACPI acpi_device_id:

        rfkill->type = (unsigned)id->driver_data;

and there is no "type" property so device_property_read_string() will fail
and leave type_name uninitialized, leading to a potential crash.

rfkill_find_type() does accept a NULL pointer, fix the potential crash
by initializing type_name to NULL.

Note likely sofar this has not been caught because:

1. Not many x86 machines actually have a "BCM4752"/"LNV4752" acpi_device
2. The stack happened to contain NULL where type_name is stored

Fixes: 7d5e9737efda ("net: rfkill: gpio: get the name and type from device property")
Cc: stable@vger.kernel.org
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Hans de Goede <hansg@kernel.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://patch.msgid.link/20250913113515.21698-1-hansg@kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/rfkill/rfkill-gpio.c b/net/rfkill/rfkill-gpio.c
index 41e657e97761..cf2dcec6ce5a 100644
--- a/net/rfkill/rfkill-gpio.c
+++ b/net/rfkill/rfkill-gpio.c
@@ -94,10 +94,10 @@ static const struct dmi_system_id rfkill_gpio_deny_table[] = {
 static int rfkill_gpio_probe(struct platform_device *pdev)
 {
 	struct rfkill_gpio_data *rfkill;
-	struct gpio_desc *gpio;
+	const char *type_name = NULL;
 	const char *name_property;
 	const char *type_property;
-	const char *type_name;
+	struct gpio_desc *gpio;
 	int ret;
 
 	if (dmi_check_system(rfkill_gpio_deny_table))