From: Andrew Lunn <andrew@lunn.ch>
To: hancock@sedsystems.ca
Cc: Heiner Kallweit <hkallweit1@gmail.com>,
netdev@vger.kernel.org, Florian Fainelli <f.fainelli@gmail.com>
Subject: Re: [PATCH net-next] net: phy: Ensure scheduled work is cancelled during removal
Date: Sat, 1 Jun 2019 17:46:36 +0200 [thread overview]
Message-ID: <20190601154636.GA19081@lunn.ch> (raw)
In-Reply-To: <8fc39ed123aede7ab23954ba06ff4cd5.squirrel@intranet.sedsystems.ca>
On Fri, May 31, 2019 at 09:22:16PM -0600, hancock@sedsystems.ca wrote:
> > On 31.05.2019 22:54, Andrew Lunn wrote:
> >>> It is possible that scheduled work started by the PHY driver is still
> >>> outstanding when phy_device_remove is called if the PHY was initially
> >>> started but never connected, and therefore phy_disconnect is never
> >>> called. phy_stop does not guarantee that the scheduled work is stopped
> >>> because it is called under rtnl_lock. This can cause an oops due to
> >>> use-after-free if the delayed work fires after freeing the PHY device.
> >>>
> > The patch itself at least shouldn't do any harm. However the justification
> > isn't fully convincing yet.
> > PHY drivers don't start any scheduled work. This queue is used by the
> > phylib state machine. phy_stop usually isn't called under rtnl_lock,
> > and it calls phy_stop_machine that cancels pending work.
> > Did you experience such an oops? Can you provide a call chain where
> > your described scenario could happen?
>
> Upon further investigation, it appears that this change is no longer
> needed in the mainline. Previously (such as in 4.19 kernels as we are
> using),
Hi Robert
Please do all your testing on net-next. 4.19 is dead, in terms of
development. There is no point in developing and testing on it patches
intended for mainline.
Andrew
next prev parent reply other threads:[~2019-06-01 15:46 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-31 19:15 [PATCH net-next] net: phy: xilinx: add Xilinx PHY driver Robert Hancock
2019-05-31 19:15 ` [PATCH net-next] net: phy: Ensure scheduled work is cancelled during removal Robert Hancock
2019-05-31 20:54 ` Andrew Lunn
2019-05-31 21:26 ` Heiner Kallweit
2019-06-01 3:22 ` hancock
2019-06-01 15:46 ` Andrew Lunn [this message]
2019-05-31 20:52 ` [PATCH net-next] net: phy: xilinx: add Xilinx PHY driver Andrew Lunn
2019-05-31 21:11 ` Florian Fainelli
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