From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: kernel panic with time-stamping in phy devices (monitor mode) Date: Thu, 02 Dec 2010 17:38:04 +0100 Message-ID: <1291307884.2871.69.camel@edumazet-laptop> References: <252997.92320.qm@web111013.mail.gq1.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: netdev@vger.kernel.org To: Andrew Watts Return-path: Received: from mail-wy0-f174.google.com ([74.125.82.174]:39000 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752816Ab0LBQpE (ORCPT ); Thu, 2 Dec 2010 11:45:04 -0500 Received: by wyb28 with SMTP id 28so8400314wyb.19 for ; Thu, 02 Dec 2010 08:45:03 -0800 (PST) In-Reply-To: <252997.92320.qm@web111013.mail.gq1.yahoo.com> Sender: netdev-owner@vger.kernel.org List-ID: Le jeudi 02 d=C3=A9cembre 2010 =C3=A0 08:05 -0800, Andrew Watts a =C3=A9= crit : > Hi. >=20 > The 'time stamping in phy devices' code introduced in 2.6.36 > (c1f19b51d1d87f3e3bb7e6648f43f7d57ed2da6b et al.) triggers > kernel panics when wireless devices are placed in monitor mode > (tested with b43 and ath5k devices on a 32-bit system). >=20 > To reproduce, set CONFIG_NETWORK_PHY_TIMESTAMPING=3Dy and put a > wireless device into monitor mode: >=20 > # ifconfig wlan0 down > # iwconfig wlan0 mode monitor=20 > # ifconfig wlan0 up >=20 > ~ Andy >=20 > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >=20 > [] ? __alloc_skb+0x53/0xf8 > [] ? b43_dma_rx+0x18a/0x342 [b43] > [] ? b43_do_interrupt_thread+0x420/0x92e [b43] > [] ? __dequeue_entity+0x31/0x35 > [] ? set_next_entity+0xad/0xbb > [] ? b43_interrupt_thread_handler+0x18/0x2b [b43] > [] ? irq_thread+0xb6/0x19e > [] ? schedule+0x254/0x566 > [] ? irq_thread+0x0/0x19e > [] ? kthread+0x67/0x69 > [] ? kthread+0x0/0x69 > [] ? kernel_thread_helper+0x6/0x18 > Code: 4c 24 14 8b 88 a8 00 00 00 89 4c 24 10 89 54 24 0c 8b > 40 50 89 44 24 08 8b 45 04 89 44 24 04 c7 04 24 30 74 7a c1 > e8 b5 d2 11 00 <0f> 0b eb fe 55 89 e5 56 53 83 ec 24 8b 88 > a0 00 00 00 8b 58 54 > EIP: [] skb_push+0x7d/0x81 SS:ESP 0068:cee01d78 > ---[ end trace af1c99818e62b195 ]--- > Kernel panic - not syncing: Fatal exception in interrupt > Pid: 6674, comm: irq/18-b43 Tainted: G D 2.6.36.1 > Call Trace: > [] ? printk+0x28/0x2a > [] panic+0x57/0x150 > [] oops_begin+0x0/0x40 > [] die+0x49/0x5d > [] do_trap+0x84/0xad > [] ? do_invalid_op+0x0/0x93 > [] do_invalid_op+0x86/0x93 > [] ? skb_push+0x7d/0x81 > [] error_code+0x65/0x6c > [] ? skb_push+0x7d/0x81 > [] ? skb_defer_rx_timestamp+0x12/0x5a > [] skb_defer_rx_timestamp+0x12/0x5a > [] netif_receive_skb+0x1f/0x47 > [] ieee80211_rx+0x661/0x8e1 > [] ? ssb_pci_read32+0x19/0x31 [ssb] > [] ? b43_tsf_read+0x2a/0x47 [b43] > [] b43_rx+0x24c/0x5eb [b43] > [] ? __alloc_skb+0x53/0xf8 > [] b43_dma_rx+0x18a/0x342 [b43] > [] b43_do_interrupt_thread+0x420/0x92e [b43] > [] ? __dequeue_entity+0x31/0x35 > [] ? set_next_entity+0xad/0xbb > [] b43_interrupt_thread_handler+0x18/0x2b [b43] > [] irq_thread+0xb6/0x19e > [] ? schedule+0x254/0x566 > [] ? irq_thread+0x0/0x19e > [] kthread+0x67/0x69 > [] ? kthread+0x0/0x69 > [] kernel_thread_helper+0x6/0x18 >=20 >=20 Thanks for the report Please try following patch. diff --git a/net/core/timestamping.c b/net/core/timestamping.c index dac7ed6..a710ab0 100644 --- a/net/core/timestamping.c +++ b/net/core/timestamping.c @@ -96,7 +96,10 @@ bool skb_defer_rx_timestamp(struct sk_buff *skb) struct phy_device *phydev; unsigned int type; =20 - skb_push(skb, ETH_HLEN); + if (skb->data - ETH_HLEN < skb->head) + return false; + + __skb_push(skb, ETH_HLEN); =20 type =3D classify(skb); =20