From 26783d74cc6a440ee3ef9836a008a697981013d0 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Fri, 29 Jan 2021 17:37:24 +0300
Subject: [PATCH] mfd: wm831x-auxadc: Prevent use after free in wm831x_auxadc_read_irq()
Git-commit: 26783d74cc6a440ee3ef9836a008a697981013d0
Patch-mainline: v5.12-rc1
References: git-fixes
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@oracle.com>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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 8a7cc0f86958..65b98f3fbd92 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);
--
2.26.2