This is a note to let you know that I've just added the patch titled mfd: wm831x-auxadc: Prevent use after free in wm831x_auxadc_read_irq() to the 5.11-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mfd-wm831x-auxadc-prevent-use-after-free-in-wm831x_a.patch and it can be found in the queue-5.11 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 8046d3c430fcc1d97b856823db1164c2f14edabf Author: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Date: Fri Jan 29 17:37:24 2021 +0300 mfd: wm831x-auxadc: Prevent use after free in wm831x_auxadc_read_irq() [ Upstream commit 26783d74cc6a440ee3ef9836a008a697981013d0 ] The "req" struct is always added to the "wm831x->auxadc_pending" list, but it's only removed from the list on the success path. If a failure occurs then the "req" struct is freed but it's still on the list, leading to a use after free. Fixes: 78bb3688ea18 ("mfd: Support multiple active WM831x AUXADC conversions") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Acked-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx> Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/mfd/wm831x-auxadc.c b/drivers/mfd/wm831x-auxadc.c index 8a7cc0f86958b..65b98f3fbd929 100644 --- a/drivers/mfd/wm831x-auxadc.c +++ b/drivers/mfd/wm831x-auxadc.c @@ -93,11 +93,10 @@ static int wm831x_auxadc_read_irq(struct wm831x *wm831x, wait_for_completion_timeout(&req->done, msecs_to_jiffies(500)); mutex_lock(&wm831x->auxadc_lock); - - list_del(&req->list); ret = req->val; out: + list_del(&req->list); mutex_unlock(&wm831x->auxadc_lock); kfree(req);