From: Liu Xiang <liu.xiang@zlingsmart.com>
To: linux-gpio@vger.kernel.org
Cc: jernej.skrabec@siol.net, liuxiang_1999@126.com,
linus.walleij@linaro.org, linux-kernel@vger.kernel.org,
mripard@kernel.org, Liu Xiang <liu.xiang@zlingsmart.com>,
wens@csie.org, linux-arm-kernel@lists.infradead.org
Subject: [PATCH] pinctrl: sunxi: fix use-after-free in sunxi_pmx_free()
Date: Tue, 19 Jan 2021 14:29:08 +0800 [thread overview]
Message-ID: <20210119062908.20169-1-liu.xiang@zlingsmart.com> (raw)
When CONFIG_REGULATOR is not set, sunxi_pmx_request() always return
success. Even a group of pins call sunxi_pmx_request(), the refcount
is only 1. This can cause a use-after-free warning in sunxi_pmx_free().
To solve this problem, go to err path if regulator_get() return NULL
or error.
Signed-off-by: Liu Xiang <liu.xiang@zlingsmart.com>
---
drivers/pinctrl/sunxi/pinctrl-sunxi.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/pinctrl/sunxi/pinctrl-sunxi.c b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
index dc8d39ae0..d1a8974eb 100644
--- a/drivers/pinctrl/sunxi/pinctrl-sunxi.c
+++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
@@ -777,7 +777,7 @@ static int sunxi_pmx_request(struct pinctrl_dev *pctldev, unsigned offset)
snprintf(supply, sizeof(supply), "vcc-p%c", 'a' + bank);
reg = regulator_get(pctl->dev, supply);
- if (IS_ERR(reg)) {
+ if (IS_ERR_OR_NULL(reg)) {
dev_err(pctl->dev, "Couldn't get bank P%c regulator\n",
'A' + bank);
return PTR_ERR(reg);
@@ -811,7 +811,7 @@ static int sunxi_pmx_free(struct pinctrl_dev *pctldev, unsigned offset)
PINS_PER_BANK;
struct sunxi_pinctrl_regulator *s_reg = &pctl->regulators[bank_offset];
- if (!refcount_dec_and_test(&s_reg->refcount))
+ if (!s_reg->regulator || !refcount_dec_and_test(&s_reg->refcount))
return 0;
regulator_disable(s_reg->regulator);
--
2.17.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2021-01-19 6:32 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-19 6:29 Liu Xiang [this message]
2021-01-21 16:40 ` [PATCH] pinctrl: sunxi: fix use-after-free in sunxi_pmx_free() Maxime Ripard
2021-01-22 22:53 ` Linus Walleij
[not found] ` <5c4b7a8c-c549-43ae-8ec6-5ae3ed26d321.liu.xiang@zlingsmart.com>
2021-01-26 15:03 ` Linus Walleij
2021-01-26 15:24 ` Maxime Ripard
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210119062908.20169-1-liu.xiang@zlingsmart.com \
--to=liu.xiang@zlingsmart.com \
--cc=jernej.skrabec@siol.net \
--cc=linus.walleij@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-gpio@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=liuxiang_1999@126.com \
--cc=mripard@kernel.org \
--cc=wens@csie.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox