From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ivaylo Dimitrov Subject: Re: [OOPS] In __netif_receive_skb_core Date: Tue, 12 Jan 2016 09:16:16 +0200 Message-ID: <5694A840.8030900@gmail.com> References: <568EA671.7000502@gmail.com> <56929985.3020502@gmail.com> <1452457610.16445.13.camel@edumazet-glaptop2.roam.corp.google.com> <5694188F.80907@gmail.com> <56944DFA.4050002@gmail.com> <1452560786.1223.6.camel@edumazet-glaptop2.roam.corp.google.com> <1452565288.1223.10.camel@edumazet-glaptop2.roam.corp.google.com> <1452565515.1223.11.camel@edumazet-glaptop2.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Salam Noureddine , "David S. Miller" , =?UTF-8?Q?Pali_Roh=c3=a1r?= , Network Development , LKML , Sebastian Reichel , "linux-omap@vger.kernel.org" To: Eric Dumazet Return-path: In-Reply-To: <1452565515.1223.11.camel@edumazet-glaptop2.roam.corp.google.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 12.01.2016 04:25, Eric Dumazet wrote: > On Mon, 2016-01-11 at 18:21 -0800, Eric Dumazet wrote: >> On Mon, 2016-01-11 at 17:19 -0800, Salam Noureddine wrote: >>> It must be that skb->dev was changed to NULL inside of >>> __netif_receive_skb_core, otherwise we would have crashed much >>> earlier. Also, orig_dev is saved at the beginning. Possibly a device >>> is layered on top of the original device. Exactly (skb->dev was changed to NULL ...). Do you think it makes sense to put printks in various places in __netif_receive_skb_core to see after which function call skb->dev turns into NULL? > > OK please try this fix : > > diff --git a/net/phonet/af_phonet.c b/net/phonet/af_phonet.c > index 10d42f3220ab..f925753668a7 100644 > --- a/net/phonet/af_phonet.c > +++ b/net/phonet/af_phonet.c > @@ -377,6 +377,10 @@ static int phonet_rcv(struct sk_buff *skb, struct net_device *dev, > struct sockaddr_pn sa; > u16 len; > > + skb = skb_share_check(skb, GFP_ATOMIC); > + if (!skb) > + return NET_RX_DROP; > + > /* check we have at least a full Phonet header */ > if (!pskb_pull(skb, sizeof(struct phonethdr))) > goto out; > > That one fixes the oops, though I wonder if your previous patch is needed (I reverted it before testing the current). Unfortunately I don't have SIM card around to test GPRS connection with, will do it as soon as I find one and will report. Thanks, Ivo