From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jay Vosburgh Subject: Re: [PATCH] Ensure that we unshare skbs prior to calling pskb_may_pull in bonding driver Date: Thu, 20 Jan 2011 11:43:09 -0800 Message-ID: <3874.1295552589@death> References: <1295550151-25913-1-git-send-email-nhorman@tuxdriver.com> Cc: netdev@vger.kernel.org, Andy Gospodarek , "David S. Miller" To: Neil Horman Return-path: Received: from e9.ny.us.ibm.com ([32.97.182.139]:46340 "EHLO e9.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752757Ab1ATTn3 (ORCPT ); Thu, 20 Jan 2011 14:43:29 -0500 Received: from d01dlp01.pok.ibm.com (d01dlp01.pok.ibm.com [9.56.224.56]) by e9.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id p0KJJ4GC029907 for ; Thu, 20 Jan 2011 14:19:04 -0500 Received: from d01relay01.pok.ibm.com (d01relay01.pok.ibm.com [9.56.227.233]) by d01dlp01.pok.ibm.com (Postfix) with ESMTP id 29C39728051 for ; Thu, 20 Jan 2011 14:43:23 -0500 (EST) Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by d01relay01.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p0KJhCtt389776 for ; Thu, 20 Jan 2011 14:43:13 -0500 Received: from d01av01.pok.ibm.com (loopback [127.0.0.1]) by d01av01.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p0KJhC3e000858 for ; Thu, 20 Jan 2011 14:43:12 -0500 In-reply-to: <1295550151-25913-1-git-send-email-nhorman@tuxdriver.com> Sender: netdev-owner@vger.kernel.org List-ID: Neil Horman wrote: >Recently reported oops: > >kernel BUG at net/core/skbuff.c:813! >invalid opcode: 0000 [#1] SMP >last sysfs file: /sys/devices/virtual/net/bond0/broadcast >CPU 8 >Modules linked in: sit tunnel4 cpufreq_ondemand acpi_cpufreq freq_table bonding >ipv6 dm_mirror dm_region_hash dm_log cdc_ether usbnet mii serio_raw i2c_i801 >i2c_core iTCO_wdt iTCO_vendor_support shpchp ioatdma i7core_edac edac_core bnx2 >ixgbe dca mdio sg ext4 mbcache jbd2 sd_mod crc_t10dif mptsas mptscsih mptbase >scsi_transport_sas dm_mod [last unloaded: microcode] > >Modules linked in: sit tunnel4 cpufreq_ondemand acpi_cpufreq freq_table bonding >ipv6 dm_mirror dm_region_hash dm_log cdc_ether usbnet mii serio_raw i2c_i801 >i2c_core iTCO_wdt iTCO_vendor_support shpchp ioatdma i7core_edac edac_core bnx2 >ixgbe dca mdio sg ext4 mbcache jbd2 sd_mod crc_t10dif mptsas mptscsih mptbase >scsi_transport_sas dm_mod [last unloaded: microcode] >Pid: 0, comm: swapper Not tainted 2.6.32-71.el6.x86_64 #1 BladeCenter HS22 >-[7870AC1]- >RIP: 0010:[] [] >pskb_expand_head+0x36/0x1e0 >RSP: 0018:ffff880028303b70 EFLAGS: 00010202 >RAX: 0000000000000002 RBX: ffff880c6458ec80 RCX: 0000000000000020 >RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880c6458ec80 >RBP: ffff880028303bc0 R08: ffffffff818a6180 R09: ffff880c6458ed64 >R10: ffff880c622b36c0 R11: 0000000000000400 R12: 0000000000000000 >R13: 0000000000000180 R14: ffff880c622b3000 R15: 0000000000000000 >FS: 0000000000000000(0000) GS:ffff880028300000(0000) knlGS:0000000000000000 >CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b >CR2: 00000038653452a4 CR3: 0000000001001000 CR4: 00000000000006e0 >DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 >Process swapper (pid: 0, threadinfo ffff8806649c2000, task ffff880c64f16ab0) >Stack: > ffff880028303bc0 ffffffff8104fff9 000000000000001c 0000000100000000 ><0> ffff880000047d80 ffff880c6458ec80 000000000000001c ffff880c6223da00 ><0> ffff880c622b3000 0000000000000000 ffff880028303c10 ffffffff81407f7a >Call Trace: > > [] ? __wake_up_common+0x59/0x90 > [] __pskb_pull_tail+0x2aa/0x360 > [] bond_arp_rcv+0x2c0/0x2e0 [bonding] > [] ? packet_rcv+0x377/0x440 > [] netif_receive_skb+0x2db/0x670 > [] napi_skb_finish+0x58/0x70 > [] napi_gro_receive+0x39/0x50 > [] ixgbe_clean_rx_irq+0x35b/0x900 [ixgbe] > [] ixgbe_clean_rxtx_many+0x136/0x240 [ixgbe] > [] net_rx_action+0x103/0x210 > [] __do_softirq+0xb7/0x1e0 > [] ? handle_IRQ_event+0x60/0x170 > [] call_softirq+0x1c/0x30 > [] do_softirq+0x65/0xa0 > [] irq_exit+0x85/0x90 > [] do_IRQ+0x75/0xf0 > [] ret_from_intr+0x0/0x11 > > [] ? mwait_idle+0x71/0xd0 > [] ? atomic_notifier_call_chain+0x1a/0x20 > [] cpu_idle+0xb6/0x110 > [] start_secondary+0x1fc/0x23f > >Resulted from bonding driver registering packet handlers via dev_add_pack and >then trying to call pskb_may_pull. If another packet handler (like for AF_PACKET >sockets) gets called first, the delivered skb will have a user count > 1, which >causes pskb_may_pull to BUG halt when it does its skb_shared check. Fix this by >calling skb_share_check prior to the may_pull call sites in the bonding driver >to clone the skb when needed. Tested by myself and the reported successfully. > >Signed-off-by: Neil Horman >CC: Andy Gospodarek >CC: Jay Vosburgh >CC: "David S. Miller" Looks like a candidate for -stable as well. -J Signed-off-by: Jay Vosburgh >--- > drivers/net/bonding/bond_3ad.c | 4 ++++ > drivers/net/bonding/bond_alb.c | 4 ++++ > drivers/net/bonding/bond_main.c | 4 ++++ > 3 files changed, 12 insertions(+), 0 deletions(-) > >diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c >index 171782e..1024ae1 100644 >--- a/drivers/net/bonding/bond_3ad.c >+++ b/drivers/net/bonding/bond_3ad.c >@@ -2470,6 +2470,10 @@ int bond_3ad_lacpdu_recv(struct sk_buff *skb, struct net_device *dev, struct pac > if (!(dev->flags & IFF_MASTER)) > goto out; > >+ skb = skb_share_check(skb, GFP_ATOMIC); >+ if (!skb) >+ goto out; >+ > if (!pskb_may_pull(skb, sizeof(struct lacpdu))) > goto out; > >diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c >index f4e638c..5c6fba8 100644 >--- a/drivers/net/bonding/bond_alb.c >+++ b/drivers/net/bonding/bond_alb.c >@@ -326,6 +326,10 @@ static int rlb_arp_recv(struct sk_buff *skb, struct net_device *bond_dev, struct > goto out; > } > >+ skb = skb_share_check(skb, GFP_ATOMIC); >+ if (!skb) >+ goto out; >+ > if (!pskb_may_pull(skb, arp_hdr_len(bond_dev))) > goto out; > >diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c >index b1025b8..163e0b0 100644 >--- a/drivers/net/bonding/bond_main.c >+++ b/drivers/net/bonding/bond_main.c >@@ -2733,6 +2733,10 @@ static int bond_arp_rcv(struct sk_buff *skb, struct net_device *dev, struct pack > if (!slave || !slave_do_arp_validate(bond, slave)) > goto out_unlock; > >+ skb = skb_share_check(skb, GFP_ATOMIC); >+ if (!skb) >+ goto out_unlock; >+ > if (!pskb_may_pull(skb, arp_hdr_len(dev))) > goto out_unlock; > >-- >1.7.3.4 > --- -Jay Vosburgh, IBM Linux Technology Center, fubar@us.ibm.com