From: Benjamin Tissoires <benjamin.tissoires@redhat.com>

Date: Thu, 16 Feb 2023 11:22:58 +0100

Subject: [PATCH] HID: mcp-2221: prevent UAF in delayed work

References: bsc#1012628

Patch-mainline: 6.2.1

Git-commit: 47e91fdfa511139f2549687edb0d8649b123227b

commit 47e91fdfa511139f2549687edb0d8649b123227b upstream.

If the device is plugged/unplugged without giving time for mcp_init_work()

to complete, we might kick in the devm free code path and thus have

unavailable struct mcp_2221 while in delayed work.

Canceling the delayed_work item is enough to solve the issue, because

cancel_delayed_work_sync will prevent the work item to requeue itself.

Fixes: 960f9df7c620 ("HID: mcp2221: add ADC/DAC support via iio subsystem")

CC: stable@vger.kernel.org

Acked-by: Jiri Kosina <jkosina@suse.cz>

Link: https://lore.kernel.org/r/20230215-wip-mcp2221-v2-1-109f71fd036e@redhat.com

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Jiri Slaby <jslaby@suse.cz>

---

 drivers/hid/hid-mcp2221.c | 3 +++

 1 file changed, 3 insertions(+)

diff --git a/drivers/hid/hid-mcp2221.c b/drivers/hid/hid-mcp2221.c

index e61dd039..f74a977c 100644

--- a/drivers/hid/hid-mcp2221.c

+++ b/drivers/hid/hid-mcp2221.c

@@ -922,6 +922,9 @@ static void mcp2221_hid_unregister(void *ptr)

 /* This is needed to be sure hid_hw_stop() isn't called twice by the subsystem */

 static void mcp2221_remove(struct hid_device *hdev)

 {

+	struct mcp2221 *mcp = hid_get_drvdata(hdev);

+

+	cancel_delayed_work_sync(&mcp->init_work);

 }

 #if IS_REACHABLE(CONFIG_IIO)

-- 

2.35.3