[PATCH 6.1.y] vxlan: use pskb_network_may_pull() for transmit path header pulls

[PATCH 6.1.y] vxlan: use pskb_network_may_pull() for transmit path header pulls

[Miguel Gazquez (Schneider Electric)]

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit b9553558b48db54ac9273e6b98d7263ef5c1a329 ]

In vxlan_xmit(), arp_reduce(), and vxlan_mdb_entry_skb_get(), pskb_may_pull() was
being called to verify the availability of network layer headers (ARP, IPv6/ND,
IP/IPv6 MDB keys).

However, during transmit skb->data points to the MAC header, so skb_network_offset(skb)
is ETH_HLEN (14 bytes). Using pskb_may_pull(skb, len) only checks len bytes from skb->data
rather than skb_network_offset(skb) + len, which can leave part of the network header
in non-linear frags.

Replace these remaining pskb_may_pull() calls with pskb_network_may_pull() to properly
account for the MAC header offset.

Fixes: e4f67addf158 ("add DOVE extensions for VXLAN")
Fixes: f564f45c4518 ("vxlan: add ipv6 proxy support")
Fixes: 0f83e69f44bf ("vxlan: Add MDB data path support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260723144249.759100-6-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Miguel Gazquez (Schneider Electric) <miguel.gazquez@bootlin.com>
---
 drivers/net/vxlan/vxlan_core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 245c4c705045..9684a3ab081b 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -1904,7 +1904,7 @@ static int arp_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni)
 	if (dev->flags & IFF_NOARP)
 		goto out;
 
-	if (!pskb_may_pull(skb, arp_hdr_len(dev))) {
+	if (!pskb_network_may_pull(skb, arp_hdr_len(dev))) {
 		dev->stats.tx_dropped++;
 		goto out;
 	}
@@ -2865,8 +2865,8 @@ static netdev_tx_t vxlan_xmit(struct sk_buff *skb, struct net_device *dev)
 			return arp_reduce(dev, skb, vni);
 #if IS_ENABLED(CONFIG_IPV6)
 		else if (ntohs(eth->h_proto) == ETH_P_IPV6 &&
-			 pskb_may_pull(skb, sizeof(struct ipv6hdr) +
-					    sizeof(struct nd_msg)) &&
+			 pskb_network_may_pull(skb, sizeof(struct ipv6hdr) +
+						    sizeof(struct nd_msg)) &&
 			 ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) {
 			struct nd_msg *m = (struct nd_msg *)(ipv6_hdr(skb) + 1);
 

---
base-commit: cf82dcca96346600c7068cf3f841335f9fa08f54
change-id: 20260907-cve-2026-74474-0f71b726bb50

Best regards,
--  
Miguel Gazquez (Schneider Electric) <miguel.gazquez@bootlin.com>

Re: [PATCH 6.1.y] vxlan: use pskb_network_may_pull() for transmit path header pulls

[Sasha Levin]

> In vxlan_xmit(), arp_reduce(), and vxlan_mdb_entry_skb_get(), pskb_may_pull() was
> being called to verify the availability of network layer headers (ARP, IPv6/ND,
> IP/IPv6 MDB keys).

Queued for 6.1, thanks.

-- 
Thanks,
Sasha