From: Wolfram Sang <wsa@the-dreams.de>
To: Xu Wang <vulab@iscas.ac.cn>
Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] i2c: Fix a potential use after free
Date: Sun, 22 Mar 2020 16:56:52 +0100 [thread overview]
Message-ID: <20200322155652.GC1091@ninjato> (raw)
In-Reply-To: <1577439272-10362-1-git-send-email-vulab@iscas.ac.cn>
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On Fri, Dec 27, 2019 at 09:34:32AM +0000, Xu Wang wrote:
> Free the adap structure only after we are done using it.
> This patch just moves the put_device() down a bit to avoid the
> use after free.
>
> Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Do you have a testcase to reproduce it?
I wonder because we are freeing the device structure which is embedded
inside the adap structure, not the adap structure itself. Or?
> ---
> drivers/i2c/i2c-core-base.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
> index 9f8dcd3..160d43e 100644
> --- a/drivers/i2c/i2c-core-base.c
> +++ b/drivers/i2c/i2c-core-base.c
> @@ -2301,8 +2301,8 @@ void i2c_put_adapter(struct i2c_adapter *adap)
> if (!adap)
> return;
>
> - put_device(&adap->dev);
> module_put(adap->owner);
> + put_device(&adap->dev);
> }
> EXPORT_SYMBOL(i2c_put_adapter);
>
> --
> 2.7.4
>
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next prev parent reply other threads:[~2020-03-22 15:56 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-27 9:34 [PATCH 2/2] i2c: Fix a potential use after free Xu Wang
2019-12-28 12:50 ` Markus Elfring
2020-03-22 15:56 ` Wolfram Sang [this message]
2022-06-16 21:00 ` Wolfram Sang
2022-07-26 21:13 ` Wolfram Sang
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