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From: wenxu <wenxu@ucloud.cn>
To: pshelar@nicira.com, davem@davemloft.net, jesse@kernel.org
Cc: netdev@vger.kernel.org, dev@openvswitch.org,
	linux-kernel@vger.kernel.org, wenxu@ucloud.cn
Subject: [PATCH] [stable 4.1.y PACTH] openvswitch: fix crash cause by non-nvgre packet
Date: Tue, 22 Dec 2015 17:15:59 +0800	[thread overview]
Message-ID: <1450775759-11059-1-git-send-email-wenxu@ucloud.cn> (raw)

kernel BUG at include/linux/skbuff.h:1219!
invalid opcode: 0000 [#1] SMP
RIP: 0010:[<ffffffffa01dc89d>] ovs_flow_extract+0x8ed/0xa40 [openvswitch]
Call Trace:
<IRQ>
ovs_dp_process_received_packet+0x44/0x80 [openvswitch]
ovs_vport_receive+0x2e/0x30 [openvswitch]
gre_rcv+0xac/0xd0 [openvswitch]
gre_cisco_rcv+0x1c2/0x310 [openvswitch]
gre_rcv+0x59/0x80 [openvswitch]

ovs_flow_extract call __skb_pull to lead BUG_ON(skb->len < skb->data_len)
if the gre header protocol is not TEB and most part of the packet is in
the nolinear-spatial.

1. gre_rcv: pskb_may_pull(skb, 12)
pull the 12 bytes to linear-spatial(skb->data). The gre header is 8 bytes
only with key.

2. gre_cisco_rcv-->parse_gre_header-->iptunnel_pull_header
{
    if (inner_proto == htons(ETH_P_TEB)) {
        struct ethhdr *eh;

        if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
            return -ENOMEM;
        ......
    }
}
The wrong inner_proto leads no pull the Mac header to linear-spatial

3. finally It made a crash in ovs_flow_extract->__skb_pull

Signed-off-by: wenxu <wenxu@ucloud.cn>
---
 net/openvswitch/vport-gre.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/openvswitch/vport-gre.c b/net/openvswitch/vport-gre.c
index f17ac96..4a993b5 100644
--- a/net/openvswitch/vport-gre.c
+++ b/net/openvswitch/vport-gre.c
@@ -107,6 +107,9 @@ static int gre_rcv(struct sk_buff *skb,
 	if (unlikely(!vport))
 		return PACKET_REJECT;
 
+	if (unlikely(tpi->proto != htons(ETH_P_TEB)))
+		return PACKET_REJECT;
+
 	key = key_to_tunnel_id(tpi->key, tpi->seq);
 	ovs_flow_tun_info_init(&tun_info, ip_hdr(skb), 0, 0, key,
 			       filter_tnl_flags(tpi->flags), NULL, 0);
-- 
1.9.1



WARNING: multiple messages have this Message-ID (diff)
From: wenxu <wenxu-t3UIVg6hrfr/PtFMR13I2A@public.gmane.org>
To: pshelar-l0M0P4e3n4LQT0dZR+AlfA@public.gmane.org,
	davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org,
	jesse-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org
Cc: dev-yBygre7rU0TnMu66kgdUjQ@public.gmane.org,
	netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	wenxu-t3UIVg6hrfr/PtFMR13I2A@public.gmane.org
Subject: [PATCH] [stable 4.1.y PACTH] openvswitch: fix crash cause by non-nvgre packet
Date: Tue, 22 Dec 2015 17:15:59 +0800	[thread overview]
Message-ID: <1450775759-11059-1-git-send-email-wenxu@ucloud.cn> (raw)

kernel BUG at include/linux/skbuff.h:1219!
invalid opcode: 0000 [#1] SMP
RIP: 0010:[<ffffffffa01dc89d>] ovs_flow_extract+0x8ed/0xa40 [openvswitch]
Call Trace:
<IRQ>
ovs_dp_process_received_packet+0x44/0x80 [openvswitch]
ovs_vport_receive+0x2e/0x30 [openvswitch]
gre_rcv+0xac/0xd0 [openvswitch]
gre_cisco_rcv+0x1c2/0x310 [openvswitch]
gre_rcv+0x59/0x80 [openvswitch]

ovs_flow_extract call __skb_pull to lead BUG_ON(skb->len < skb->data_len)
if the gre header protocol is not TEB and most part of the packet is in
the nolinear-spatial.

1. gre_rcv: pskb_may_pull(skb, 12)
pull the 12 bytes to linear-spatial(skb->data). The gre header is 8 bytes
only with key.

2. gre_cisco_rcv-->parse_gre_header-->iptunnel_pull_header
{
    if (inner_proto == htons(ETH_P_TEB)) {
        struct ethhdr *eh;

        if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
            return -ENOMEM;
        ......
    }
}
The wrong inner_proto leads no pull the Mac header to linear-spatial

3. finally It made a crash in ovs_flow_extract->__skb_pull

Signed-off-by: wenxu <wenxu@ucloud.cn>
---
 net/openvswitch/vport-gre.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/openvswitch/vport-gre.c b/net/openvswitch/vport-gre.c
index f17ac96..4a993b5 100644
--- a/net/openvswitch/vport-gre.c
+++ b/net/openvswitch/vport-gre.c
@@ -107,6 +107,9 @@ static int gre_rcv(struct sk_buff *skb,
 	if (unlikely(!vport))
 		return PACKET_REJECT;
 
+	if (unlikely(tpi->proto != htons(ETH_P_TEB)))
+		return PACKET_REJECT;
+
 	key = key_to_tunnel_id(tpi->key, tpi->seq);
 	ovs_flow_tun_info_init(&tun_info, ip_hdr(skb), 0, 0, key,
 			       filter_tnl_flags(tpi->flags), NULL, 0);
-- 
1.9.1


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             reply	other threads:[~2015-12-22  9:19 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-22  9:15 wenxu [this message]
2015-12-22  9:15 ` [PATCH] [stable 4.1.y PACTH] openvswitch: fix crash cause by non-nvgre packet wenxu

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