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Date:   Sun, 27 Mar 2022 11:51:05 +0200
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Jakub Kicinski <kuba@kernel.org>
Cc:     Pavel Machek <pavel@denx.de>, linux-kernel@vger.kernel.org,
        stable@vger.kernel.org, Eric Dumazet <edumazet@google.com>,
        =?utf-8?B?6LW15a2Q6L2p?= <beraphin@gmail.com>,
        Stoyan Manolov <smanolov@suse.de>
Subject: Re: [PATCH 5.10 09/38] llc: fix netdevice reference leaks in
 llc_ui_bind()
Message-ID: <YkAziXrW7/Fbqo/b@kroah.com>
References: <20220325150419.757836392@linuxfoundation.org>
 <20220325150420.029041400@linuxfoundation.org>
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On Sat, Mar 26, 2022 at 01:13:25PM -0700, Jakub Kicinski wrote:
> On Sat, 26 Mar 2022 21:09:22 +0100 Pavel Machek wrote:
> > Can someone check this? AFAICT this is buggy.
> > 
> > static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
> > {
> >         struct sock *sk = sock->sk;
> >         struct llc_sock *llc = llc_sk(sk);
> >         struct llc_sap *sap;
> >         int rc = -EINVAL;
> > 
> >         if (!sock_flag(sk, SOCK_ZAPPED))
> >                 goto out;
> > 
> > There are 'goto out's from both before dev_get() and after it,
> > dev_put() will be called with NULL pointer. dev_put() can't handle
> > NULL at least in the old kernels... this is simply confused.
> > 
> > Mainline has dev_put_track() there, but I see same confusion.
> > 
> > Best regards,
> 
> commit 2d327a79ee17 ("llc: only change llc->dev when bind() succeeds"),
> https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=2d327a79ee176930dc72c131a970c891d367c1dc
> 
> Should be in mainline on Thursday, LMK if we need to accelerate.
> IDK if anyone enables LLC2.

I'll queue this up now, thanks.

greg k-h