From 4906f9985e310fc01f956256b0d58ac28b0dcb19 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Mon, 9 Feb 2009 15:07:18 -0800 Subject: [PATCH] bridge: Fix LRO crash with tun > Kernel BUG at drivers/net/tun.c:444 > invalid opcode: 0000 [1] SMP > last sysfs file: /class/net/lo/ifindex > CPU 0 > Modules linked in: tun ipt_MASQUERADE iptable_nat ip_nat xt_state ip_conntrack > nfnetlink ipt_REJECT xt_tcpudp iptable_filter d > Pid: 6912, comm: qemu-kvm Tainted: G 2.6.18-128.el5 #1 > RIP: 0010:[] [] > :tun:tun_chr_readv+0x2b1/0x3a6 > RSP: 0018:ffff8102202c5e48 EFLAGS: 00010246 > RAX: 0000000000000000 RBX: ffff8102202c5e98 RCX: 0000000004010000 > RDX: ffff810227063680 RSI: ffff8102202c5e9e RDI: ffff8102202c5e92 > RBP: 0000000000010ff6 R08: 0000000000000000 R09: 0000000000000001 > R10: ffff8102202c5e94 R11: 0000000000000202 R12: ffff8102275357c0 > R13: ffff81022755e500 R14: 0000000000000000 R15: ffff8102202c5ef8 > FS: 00002ae4398db980(0000) GS:ffffffff803ac000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > CR2: 00002ae4ab514000 CR3: 0000000221344000 CR4: 00000000000026e0 > Process qemu-kvm (pid: 6912, threadinfo ffff8102202c4000, task > ffff81022e58d820) > Stack: 00000000498735cb ffff810229d1a3c0 0000000000000000 ffff81022e58d820 > ffffffff8008a461 ffff81022755e528 ffff81022755e528 ffffffff8009f925 > 000005ea05ea0000 ffff8102209d0000 00001051143e1600 ffffffff8003c00e > Call Trace: > [] default_wake_function+0x0/0xe > [] enqueue_hrtimer+0x55/0x70 > [] hrtimer_start+0xbc/0xce > [] :tun:tun_chr_read+0x1a/0x1f > [] vfs_read+0xcb/0x171 > [] sys_read+0x45/0x6e > [] system_call+0x7e/0x83 > > > Code: 0f 0b 68 40 62 6f 88 c2 bc 01 f6 42 0a 08 74 0c 80 4c 24 41 > RIP [] :tun:tun_chr_readv+0x2b1/0x3a6 > RSP > <0>Kernel panic - not syncing: Fatal exception This crashed when an LRO packet generated by bnx2x reached a tun device through the bridge. We're supposed to drop it at the bridge. However, because the check was placed in br_forward instead of __br_forward, it's only effective if we are sending the packet through a single port. This patch fixes it by moving the check into __br_forward. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/bridge/br_forward.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c index bdd9cce..d2c27c8 100644 --- a/net/bridge/br_forward.c +++ b/net/bridge/br_forward.c @@ -67,6 +67,11 @@ static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb) { struct net_device *indev; + if (skb_warn_if_lro(skb)) { + kfree_skb(skb); + return; + } + indev = skb->dev; skb->dev = to->dev; skb_forward_csum(skb); @@ -89,7 +94,7 @@ void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) /* called with rcu_read_lock */ void br_forward(const struct net_bridge_port *to, struct sk_buff *skb) { - if (!skb_warn_if_lro(skb) && should_deliver(to, skb)) { + if (should_deliver(to, skb)) { __br_forward(to, skb); return; } -- 2.7.4