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From: Jakub Kicinski <kuba@kernel.org>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: netdev@vger.kernel.org,
	syzbot+3f3837e61a48d32b495f@syzkaller.appspotmail.com,
	Robin van der Gracht <robin@protonic.nl>,
	Oleksij Rempel <linux@rempel-privat.de>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Oliver Hartkopp <socketcan@hartkopp.net>,
	Marc Kleine-Budde <mkl@pengutronix.de>
Subject: Re: [Patch net] can: initialize skbcnt in j1939_tp_tx_dat_new()
Date: Thu, 8 Oct 2020 10:34:10 -0700	[thread overview]
Message-ID: <20201008103410.4fea97a5@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> (raw)
In-Reply-To: <20201008061821.24663-1-xiyou.wangcong@gmail.com>

On Wed,  7 Oct 2020 23:18:21 -0700 Cong Wang wrote:
> This fixes an uninit-value warning:
> BUG: KMSAN: uninit-value in can_receive+0x26b/0x630 net/can/af_can.c:650
> 
> Reported-and-tested-by: syzbot+3f3837e61a48d32b495f@syzkaller.appspotmail.com
> Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
> Cc: Robin van der Gracht <robin@protonic.nl>
> Cc: Oleksij Rempel <linux@rempel-privat.de>
> Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
> Cc: Oliver Hartkopp <socketcan@hartkopp.net>
> Cc: Marc Kleine-Budde <mkl@pengutronix.de>
> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
> ---
>  net/can/j1939/transport.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
> index 0cec4152f979..88cf1062e1e9 100644
> --- a/net/can/j1939/transport.c
> +++ b/net/can/j1939/transport.c
> @@ -580,6 +580,7 @@ sk_buff *j1939_tp_tx_dat_new(struct j1939_priv *priv,
>  	skb->dev = priv->ndev;
>  	can_skb_reserve(skb);
>  	can_skb_prv(skb)->ifindex = priv->ndev->ifindex;
> +	can_skb_prv(skb)->skbcnt = 0;
>  	/* reserve CAN header */
>  	skb_reserve(skb, offsetof(struct can_frame, data));

Thanks! Looks like there is another can_skb_reserve(skb) on line 1489,
is that one fine?

Marc - should I take this directly into net, in case there is a last
minute PR to Linus for 5.9?

  reply	other threads:[~2020-10-08 17:34 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-08  6:18 [Patch net] can: initialize skbcnt in j1939_tp_tx_dat_new() Cong Wang
2020-10-08 17:34 ` Jakub Kicinski [this message]
2020-10-08 20:02   ` Cong Wang
2020-10-08 21:47   ` Marc Kleine-Budde
2020-10-08 22:26     ` Jakub Kicinski
2020-10-09  6:15       ` Marc Kleine-Budde

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