From b30532515f0a62bfe17207ab00883dd262497006 Mon Sep 17 00:00:00 2001 From: Neil Horman Date: Thu, 20 Jan 2011 09:02:31 +0000 Subject: [PATCH] bonding: Ensure that we unshare skbs prior to calling pskb_may_pull 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" Signed-off-by: Jay Vosburgh Signed-off-by: Andy Gospodarek Signed-off-by: David S. Miller --- 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(+) diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c index 48cf24f..c91874d 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; -- 2.7.4