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From: "John W. Linville" <linville@tuxdriver•com>
To: Michal Kubecek <mkubecek@suse•cz>
Cc: netdev@vger•kernel.org,
	Raju Lakkaraju <Raju.Lakkaraju@microsemi•com>,
	"Allan W. Nielsen" <allan.nielsen@microsemi•com>
Subject: Re: [PATCH ethtool] ethtool: fix stack clash in do_get_phy_tunable and do_set_phy_tunable
Date: Thu, 31 May 2018 13:51:27 -0400	[thread overview]
Message-ID: <20180531175127.GA27980@tuxdriver.com> (raw)
In-Reply-To: <20180509120146.C7408A0C6F@unicorn.suse.cz>

On Wed, May 09, 2018 at 02:01:46PM +0200, Michal Kubecek wrote:
> Users reported stack clash detected when using --get-phy-tunable on
> ppc64le. Problem is caused by local variable ds of type struct
> ethtool_tunable which has last member "void *data[0]". Accessing data[0]
> (as do_get_phy_tunable() does) or adding requested value at the end (which
> is what kernel ioctl does) writes past allocated space for the variable.
> 
> Make ds part of an anonymous structure to make sure there is enough space
> for tunable value and drop the (pointless) access to ds.data[0]. The same
> problem also exists in do_set_phy_tunable().
> 
> Fixes: b0fe96dec90f ("Ethtool: Implements ETHTOOL_PHY_GTUNABLE/ETHTOOL_PHY_STUNABLE and PHY downshift")
> Signed-off-by: Michal Kubecek <mkubecek@suse•cz>

LGTM -- queued for next release...

-- 
John W. Linville		Someday the world will need a hero, and you
linville@tuxdriver•com			might be all we have.  Be ready.

      reply	other threads:[~2018-05-31 18:00 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-09 12:01 [PATCH ethtool] ethtool: fix stack clash in do_get_phy_tunable and do_set_phy_tunable Michal Kubecek
2018-05-31 17:51 ` John W. Linville [this message]

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