From 0c79abee609da83f68461835d0100c7129d8dc52 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Fri, 29 Jan 2021 17:37:24 +0300 Subject: [PATCH] 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 Acked-by: Charles Keepax Signed-off-by: Lee Jones Signed-off-by: Sasha Levin --- drivers/mfd/wm831x-auxadc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) 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);