From: David Miller <davem@davemloft.net>
To: g.nault@alphalink.fr
Cc: netdev@vger.kernel.org, paulus@samba.org, alan@linux.intel.com,
arnd@arndb.de
Subject: Re: [PATCH net] ppp: ensure file->private_data can't be overridden
Date: Mon, 14 Mar 2016 14:57:59 -0400 (EDT) [thread overview]
Message-ID: <20160314.145759.727527672385295428.davem@davemloft.net> (raw)
In-Reply-To: <20160314175940.GB1462@alphalink.fr>
From: Guillaume Nault <g.nault@alphalink.fr>
Date: Mon, 14 Mar 2016 18:59:40 +0100
> Testing ->private_data without lock in ppp_ioctl() before calling
> ppp_unattached_ioctl() is fine, because either ->private_data is
> not NULL and thus is stable, or it is and ppp_unattached_ioctl()
> takes care of not overriding ->private_data, should its value get
> modified before taking the mutex.
This is exactly the ambiguous behavior I want you to avoid.
The decision should be atomic from ppp_ioctl()'s test all the way
until ppp_unattached_ioctl() does it's work.
next prev parent reply other threads:[~2016-03-14 18:58 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-08 19:14 [PATCH net] ppp: ensure file->private_data can't be overridden Guillaume Nault
2016-03-11 19:42 ` David Miller
2016-03-14 17:59 ` Guillaume Nault
2016-03-14 18:57 ` David Miller [this message]
2016-03-14 19:09 ` Guillaume Nault
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