[v6.1.52][PATCH] Bluetooth: btsdio: fix use after free bug in btsdio_remove due to race condition

From: Deepak Rathore
Date: Wed Sep 06 2023 - 08:18:56 EST


From: Zheng Wang <zyytlz.wz@xxxxxxx>

[ Upstream commit 73f7b171b7c09139eb3c6a5677c200dc1be5f318 ]

In btsdio_probe, the data->work is bound with btsdio_work. It will be
started in btsdio_send_frame.

If the btsdio_remove runs with a unfinished work, there may be a race
condition that hdev is freed but used in btsdio_work. Fix it by
canceling the work before do cleanup in btsdio_remove.

Signed-off-by: Zheng Wang <zyytlz.wz@xxxxxxx>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
Signed-off-by: Deepak Rathore <deeratho@xxxxxxxxx>

diff --git a/drivers/bluetooth/btsdio.c b/drivers/bluetooth/btsdio.c
index 795be33f2892..f19d31ee37ea 100644
--- a/drivers/bluetooth/btsdio.c
+++ b/drivers/bluetooth/btsdio.c
@@ -357,6 +357,7 @@ static void btsdio_remove(struct sdio_func *func)
if (!data)
return;

+ cancel_work_sync(&data->work);
hdev = data->hdev;

sdio_set_drvdata(func, NULL);
--
2.35.6