6.1-stable review patch. If anyone has any objections, please let me know.
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From: Guillaume Nault gnault@redhat.com
[ Upstream commit f7789419137b18e3847d0cc41afd788c3c00663d ]
Ensure the inner IP header is part of skb's linear data before reading its ECN bits. Otherwise we might read garbage. One symptom is the system erroneously logging errors like "vxlan: non-ECT from xxx.xxx.xxx.xxx with TOS=xxxx".
Similar bugs have been fixed in geneve, ip_tunnel and ip6_tunnel (see commit 1ca1ba465e55 ("geneve: make sure to pull inner header in geneve_rx()") for example). So let's reuse the same code structure for consistency. Maybe we'll can add a common helper in the future.
Fixes: d342894c5d2f ("vxlan: virtual extensible lan") Signed-off-by: Guillaume Nault gnault@redhat.com Reviewed-by: Ido Schimmel idosch@nvidia.com Reviewed-by: Eric Dumazet edumazet@google.com Reviewed-by: Nikolay Aleksandrov razor@blackwall.org Reviewed-by: Sabrina Dubroca sd@queasysnail.net Link: https://lore.kernel.org/r/1239c8db54efec341dd6455c77e0380f58923a3c.171449573... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/vxlan/vxlan_core.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c index fbd36dff9ec27..01ce289f4abf0 100644 --- a/drivers/net/vxlan/vxlan_core.c +++ b/drivers/net/vxlan/vxlan_core.c @@ -1721,6 +1721,7 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb) bool raw_proto = false; void *oiph; __be32 vni = 0; + int nh;
/* Need UDP and VXLAN header to be present */ if (!pskb_may_pull(skb, VXLAN_HLEN)) @@ -1809,9 +1810,25 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb) skb->pkt_type = PACKET_HOST; }
- oiph = skb_network_header(skb); + /* Save offset of outer header relative to skb->head, + * because we are going to reset the network header to the inner header + * and might change skb->head. + */ + nh = skb_network_header(skb) - skb->head; + skb_reset_network_header(skb);
+ if (!pskb_inet_may_pull(skb)) { + DEV_STATS_INC(vxlan->dev, rx_length_errors); + DEV_STATS_INC(vxlan->dev, rx_errors); + vxlan_vnifilter_count(vxlan, vni, vninode, + VXLAN_VNI_STATS_RX_ERRORS, 0); + goto drop; + } + + /* Get the outer header. */ + oiph = skb->head + nh; + if (!vxlan_ecn_decapsulate(vs, oiph, skb)) { ++vxlan->dev->stats.rx_frame_errors; ++vxlan->dev->stats.rx_errors;