[lvc-project] [PATCH v2] can: fix skb reference counting in j1939_session_new()

[Marc Kleine-Budde]

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 at syzkaller.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 at yandex.ru>
> > 
> > Tested-by: Oleksij Rempel <o.rempel at pengutronix.de>
> > Acked-by: Oleksij Rempel <o.rempel at pengutronix.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 |
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