netdev - Re: [PATCH v2] can: fix skb reference counting in j1939_session

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20241129-skinny-jackrabbit-of-relaxation-903ae4-mkl@pengutronix.de>
Date: Fri, 29 Nov 2024 14:05:11 +0100
From: Marc Kleine-Budde <mkl@...gutronix.de>
To: Oleksij Rempel <o.rempel@...gutronix.de>
Cc: Dmitry Antipov <dmantipov@...dex.ru>, 
	Robin van der Gracht <robin@...tonic.nl>, Oliver Hartkopp <socketcan@...tkopp.net>, 
	linux-can@...r.kernel.org, netdev@...r.kernel.org, lvc-project@...uxtesting.org, 
	syzbot+d4e8dc385d9258220c31@...kaller.appspotmail.com
Subject: Re: [PATCH v2] can: fix skb reference counting in j1939_session_new()

On 29.11.2024 13:59:28, Marc Kleine-Budde wrote:
> On 29.11.2024 13:55:56, Oleksij Rempel wrote:
> > On Tue, Nov 05, 2024 at 12:48:23PM +0300, Dmitry Antipov wrote:
> > > Since 'j1939_session_skb_queue()' do an extra 'skb_get()' for each
> > > new skb, I assume that the same should be done for an initial one
> > > in 'j1939_session_new()' just to avoid refcount underflow.
> > > 
> > > Reported-by: syzbot+d4e8dc385d9258220c31@...kaller.appspotmail.com
> > > Closes: https://syzkaller.appspot.com/bug?extid=d4e8dc385d9258220c31
> > > Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
> > > Signed-off-by: Dmitry Antipov <dmantipov@...dex.ru>
> > 
> > Tested-by: Oleksij Rempel <o.rempel@...gutronix.de>
> > Acked-by: Oleksij Rempel <o.rempel@...gutronix.de>
> 
> Can you re-phrase the commit message. The "assume" is not appropriate :)

What about:

Since j1939_session_skb_queue() does an extra skb_get() for each new
skb, do the same for the initial one in j1939_session_new() to avoid
refcount underflow.

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde          |
Embedded Linux                   | https://www.pengutronix.de |
Vertretung Nürnberg              | Phone: +49-5121-206917-129 |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-9   |

Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)