From: Greg KH <gregkh@linuxfoundation.org>
To: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: stable@vger.kernel.org, netdev@vger.kernel.org, kuba@kernel.org,
davem@davemloft.net, jiri@resnulli.us, xiyou.wangcong@gmail.com,
jhs@mojatatu.com, vladbu@mellanox.com
Subject: Re: [PATCH 4.9.y] net: sched: prevent UAF on tc_ctl_tfilter when temporarily dropping rtnl_lock
Date: Tue, 3 May 2022 15:49:15 +0200 [thread overview]
Message-ID: <YnEy2726cz98I6YC@kroah.com> (raw)
In-Reply-To: <20220502204924.3456590-1-cascardo@canonical.com>
On Mon, May 02, 2022 at 05:49:24PM -0300, Thadeu Lima de Souza Cascardo wrote:
> When dropping the rtnl_lock for looking up for a module, the device may be
> removed, releasing the qdisc and class memory. Right after trying to load
> the module, cl_ops->put is called, leading to a potential use-after-free.
>
> Though commit e368fdb61d8e ("net: sched: use Qdisc rcu API instead of
> relying on rtnl lock") fixes this, it involves a lot of refactoring of the
> net/sched/ code, complicating its backport.
What about 4.14.y? We can not take a commit for 4.9.y with it also
being broken in 4.14.y, and yet fixed in 4.19.y, right? Anyone who
updates from 4.9 to 4.14 will have a regression.
thanks,
greg k-h
next prev parent reply other threads:[~2022-05-03 13:49 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-02 20:49 [PATCH 4.9.y] net: sched: prevent UAF on tc_ctl_tfilter when temporarily dropping rtnl_lock Thadeu Lima de Souza Cascardo
2022-05-03 13:49 ` Greg KH [this message]
2022-05-03 14:24 ` Thadeu Lima de Souza Cascardo
2022-05-03 14:27 ` Greg KH
2022-05-03 14:42 ` Thadeu Lima de Souza Cascardo
2022-05-10 11:13 ` Greg KH
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