Re: [PATCH net] net: fix skb leak in __skb_tstamp_tx()

From: Greg KH <gregkh@linuxfoundation.org>
To: Pratyush Yadav <ptyadav@amazon.de>
Cc: SeongJae Park <sj@kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Kuniyuki Iwashima <kuniyu@amazon.com>,
	Willem de Bruijn <willemb@google.com>,
	Norbert Manthey <nmanthey@amazon.de>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Subject: Re: [PATCH net] net: fix skb leak in __skb_tstamp_tx()
Date: Mon, 22 May 2023 18:08:21 +0100	[thread overview]
Message-ID: <2023052208-squad-viper-b244@gregkh> (raw)
In-Reply-To: <mafs0cz2sxpq8.fsf@amazon.de>

On Mon, May 22, 2023 at 07:03:59PM +0200, Pratyush Yadav wrote:
> On Mon, May 22 2023, SeongJae Park wrote:
> 
> > Hi Pratyush,
> >
> > On Mon, 22 May 2023 17:30:20 +0200 Pratyush Yadav <ptyadav@amazon.de> wrote:
> >
> >> Commit 50749f2dd685 ("tcp/udp: Fix memleaks of sk and zerocopy skbs with
> >> TX timestamp.") added a call to skb_orphan_frags_rx() to fix leaks with
> >> zerocopy skbs. But it ended up adding a leak of its own. When
> >> skb_orphan_frags_rx() fails, the function just returns, leaking the skb
> >> it just cloned. Free it before returning.
> >>
> >> This bug was discovered and resolved using Coverity Static Analysis
> >> Security Testing (SAST) by Synopsys, Inc.
> >>
> >> Fixes: 50749f2dd685 ("tcp/udp: Fix memleaks of sk and zerocopy skbs with TX timestamp.")
> >
> > Seems the commit has merged in several stable kernels.  Is the bug also
> > affecting those?  If so, would it be better to Cc stable@vger.kernel.org?
> >
> 
> It affects v5.4.243 at least, since that is where I first saw this. But
> I would expect it to affect other stable kernels it has been backported
> to as well. I thought using the Fixes tag pointing to the bad upstream
> commit would be enough for the stable maintainers' tooling/bots to pick
> this patch up.
> 
> In either case, +Cc stable. Link to the patch this thread is talking
> about [0].


<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>