From: Russell King - ARM Linux admin <linux@armlinux.org.uk>
To: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: andrew@lunn.ch, hkallweit1@gmail.com, davem@davemloft.net,
kuba@kernel.org, david.daney@cavium.com, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] net: mdio: Fix a double free issue in the .remove function
Date: Wed, 12 May 2021 22:44:03 +0100 [thread overview]
Message-ID: <20210512214403.GQ1336@shell.armlinux.org.uk> (raw)
In-Reply-To: <f8ad939e6d5df4cb0273ea71a418a3ca1835338d.1620855222.git.christophe.jaillet@wanadoo.fr>
On Wed, May 12, 2021 at 11:35:38PM +0200, Christophe JAILLET wrote:
> 'bus->mii_bus' have been allocated with 'devm_mdiobus_alloc_size()' in the
> probe function. So it must not be freed explicitly or there will be a
> double free.
>
> Remove the incorrect 'mdiobus_free' in the remove function.
Yes, this looks correct, thanks.
Reviewed-by: Russell King <rmk+kernel@armlinux.org.uk>
However, there's another issue in this driver that ought to be fixed.
If devm_mdiobus_alloc_size() succeeds, but of_mdiobus_register() fails,
we continue on to the next bus (which I think is reasonable.) We don't
free the bus.
When we come to the remove method however, we will call
mdiobus_unregister() on this existent but not-registered bus. Surely we
don't want to do that?
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
next prev parent reply other threads:[~2021-05-12 21:58 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-12 21:35 [PATCH] net: mdio: Fix a double free issue in the .remove function Christophe JAILLET
2021-05-12 21:44 ` Russell King - ARM Linux admin [this message]
2021-05-13 6:29 ` Christophe JAILLET
2021-05-13 8:09 ` Russell King - ARM Linux admin
2021-05-13 8:22 ` Christophe JAILLET
2021-05-12 21:44 ` Andrew Lunn
2021-05-13 6:21 ` Christophe JAILLET
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