From ebe48d368e97d007bfeb76fcb065d6cfc4c96645 Mon Sep 17 00:00:00 2001 From: Steffen Klassert Date: Mon, 7 Mar 2022 13:11:39 +0100 Subject: esp: Fix possible buffer overflow in ESP transformation The maximum message size that can be send is bigger than the maximum site that skb_page_frag_refill can allocate. So it is possible to write beyond the allocated buffer. Fix this by doing a fallback to COW in that case. v2: Avoid get get_order() costs as suggested by Linus Torvalds. Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible") Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible") Reported-by: valis Signed-off-by: Steffen Klassert --- include/net/esp.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/net/esp.h b/include/net/esp.h index 9c5637d41d95..90cd02ff77ef 100644 --- a/include/net/esp.h +++ b/include/net/esp.h @@ -4,6 +4,8 @@ #include +#define ESP_SKB_FRAG_MAXSIZE (PAGE_SIZE << SKB_FRAG_PAGE_ORDER) + struct ip_esp_hdr; static inline struct ip_esp_hdr *ip_esp_hdr(const struct sk_buff *skb) -- cgit v1.2.3-59-g8ed1b From 23c7f8d7989e1646aac82f75761b7648c355cb8a Mon Sep 17 00:00:00 2001 From: Steffen Klassert Date: Mon, 7 Mar 2022 13:11:41 +0100 Subject: net: Fix esp GSO on inter address family tunnels. The esp tunnel GSO handlers use skb_mac_gso_segment to push the inner packet to the segmentation handlers. However, skb_mac_gso_segment takes the Ethernet Protocol ID from 'skb->protocol' which is wrong for inter address family tunnels. We fix this by introducing a new skb_eth_gso_segment function. This function can be used if it is necessary to pass the Ethernet Protocol ID directly to the segmentation handler. First users of this function will be the esp4 and esp6 tunnel segmentation handlers. Fixes: c35fe4106b92 ("xfrm: Add mode handlers for IPsec on layer 2") Signed-off-by: Steffen Klassert --- include/linux/netdevice.h | 2 ++ net/core/gro.c | 25 +++++++++++++++++++++++++ net/ipv4/esp4_offload.c | 3 +-- net/ipv6/esp6_offload.c | 3 +-- 4 files changed, 29 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 8b5a314db167..f53ea7038441 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -4602,6 +4602,8 @@ int skb_csum_hwoffload_help(struct sk_buff *skb, struct sk_buff *__skb_gso_segment(struct sk_buff *skb, netdev_features_t features, bool tx_path); +struct sk_buff *skb_eth_gso_segment(struct sk_buff *skb, + netdev_features_t features, __be16 type); struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb, netdev_features_t features); diff --git a/net/core/gro.c b/net/core/gro.c index a11b286d1495..b7d2b0dc59a2 100644 --- a/net/core/gro.c +++ b/net/core/gro.c @@ -92,6 +92,31 @@ void dev_remove_offload(struct packet_offload *po) } EXPORT_SYMBOL(dev_remove_offload); +/** + * skb_eth_gso_segment - segmentation handler for ethernet protocols. + * @skb: buffer to segment + * @features: features for the output path (see dev->features) + * @type: Ethernet Protocol ID + */ +struct sk_buff *skb_eth_gso_segment(struct sk_buff *skb, + netdev_features_t features, __be16 type) +{ + struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT); + struct packet_offload *ptype; + + rcu_read_lock(); + list_for_each_entry_rcu(ptype, &offload_base, list) { + if (ptype->type == type && ptype->callbacks.gso_segment) { + segs = ptype->callbacks.gso_segment(skb, features); + break; + } + } + rcu_read_unlock(); + + return segs; +} +EXPORT_SYMBOL(skb_eth_gso_segment); + /** * skb_mac_gso_segment - mac layer segmentation handler. * @skb: buffer to segment diff --git a/net/ipv4/esp4_offload.c b/net/ipv4/esp4_offload.c index 146d4d54830c..935026f4c807 100644 --- a/net/ipv4/esp4_offload.c +++ b/net/ipv4/esp4_offload.c @@ -110,8 +110,7 @@ static struct sk_buff *xfrm4_tunnel_gso_segment(struct xfrm_state *x, struct sk_buff *skb, netdev_features_t features) { - __skb_push(skb, skb->mac_len); - return skb_mac_gso_segment(skb, features); + return skb_eth_gso_segment(skb, features, htons(ETH_P_IP)); } static struct sk_buff *xfrm4_transport_gso_segment(struct xfrm_state *x, diff --git a/net/ipv6/esp6_offload.c b/net/ipv6/esp6_offload.c index e61172d50817..3a293838a91d 100644 --- a/net/ipv6/esp6_offload.c +++ b/net/ipv6/esp6_offload.c @@ -145,8 +145,7 @@ static struct sk_buff *xfrm6_tunnel_gso_segment(struct xfrm_state *x, struct sk_buff *skb, netdev_features_t features) { - __skb_push(skb, skb->mac_len); - return skb_mac_gso_segment(skb, features); + return skb_eth_gso_segment(skb, features, htons(ETH_P_IPV6)); } static struct sk_buff *xfrm6_transport_gso_segment(struct xfrm_state *x, -- cgit v1.2.3-59-g8ed1b