| Message ID | 1239c8db54efec341dd6455c77e0380f58923a3c.1714495737.git.gnault@redhat.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | f7789419137b18e3847d0cc41afd788c3c00663d |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] vxlan: Pull inner IP header in vxlan_rcv(). | expand |
On Tue, Apr 30, 2024 at 06:50:13PM +0200, Guillaume Nault wrote: > 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>
On Wed, May 1, 2024 at 12:03 PM Ido Schimmel <idosch@nvidia.com> wrote: > > On Tue, Apr 30, 2024 at 06:50:13PM +0200, Guillaume Nault wrote: > > 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> Thanks !
On 30/04/2024 19:50, Guillaume Nault wrote: > 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> > --- > drivers/net/vxlan/vxlan_core.c | 19 ++++++++++++++++++- > 1 file changed, 18 insertions(+), 1 deletion(-) > Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
2024-04-30, 18:50:13 +0200, Guillaume Nault wrote: > 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> > --- > drivers/net/vxlan/vxlan_core.c | 19 ++++++++++++++++++- > 1 file changed, 18 insertions(+), 1 deletion(-) Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Hello: This patch was applied to netdev/net.git (main) by Jakub Kicinski <kuba@kernel.org>: On Tue, 30 Apr 2024 18:50:13 +0200 you wrote: > 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. > > [...] Here is the summary with links: - [net] vxlan: Pull inner IP header in vxlan_rcv(). https://git.kernel.org/netdev/net/c/f7789419137b You are awesome, thank you!
diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c index c9e4e03ad214..3a9148fb1422 100644 --- a/drivers/net/vxlan/vxlan_core.c +++ b/drivers/net/vxlan/vxlan_core.c @@ -1674,6 +1674,7 @@ 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)) @@ -1762,9 +1763,25 @@ 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)) { DEV_STATS_INC(vxlan->dev, rx_frame_errors); DEV_STATS_INC(vxlan->dev, rx_errors);
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> --- drivers/net/vxlan/vxlan_core.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-)