From: Vadim Fedorenko <vadim.fedorenko@linux.dev>
To: Eric Dumazet <edumazet@google.com>,
"David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>, Ido Schimmel <idosch@nvidia.com>,
Andrew Lunn <andrew+netdev@lunn.ch>,
netdev@vger.kernel.org, eric.dumazet@gmail.com,
stable@vger.kernel.org
Subject: Re: [PATCH net 5/5] vxlan: use pskb_network_may_pull() for transmit path header pulls
Date: Thu, 23 Jul 2026 17:43:55 +0100 [thread overview]
Message-ID: <f974b9e9-52e0-4f82-ac30-e84d50cee26b@linux.dev> (raw)
In-Reply-To: <20260723144249.759100-6-edumazet@google.com>
On 23/07/2026 15:42, Eric Dumazet wrote:
> 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: 465016142711 ("vxlan: Add ARP reduction support")
> Fixes: 9e061a50a116 ("vxlan: Add IPv6 Neighbor Discovery reduction support")
> Fixes: 4e94f09d84bf ("vxlan: add MDB support")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: stable@vger.kernel.org
> ---
> drivers/net/vxlan/vxlan_core.c | 6 +++---
> drivers/net/vxlan/vxlan_mdb.c | 4 ++--
> 2 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
> index 9ccbebda860480f8378918ff360deee1c46f3f7d..eff17987c5b531ecb1e2943b6274d20c1827d299 100644
> --- a/drivers/net/vxlan/vxlan_core.c
> +++ b/drivers/net/vxlan/vxlan_core.c
> @@ -1850,7 +1850,7 @@ 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_dstats_tx_dropped(dev);
> vxlan_vnifilter_count(vxlan, vni, NULL,
> VXLAN_VNI_STATS_TX_DROPS, 0);
> @@ -2763,8 +2763,8 @@ 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);
>
> diff --git a/drivers/net/vxlan/vxlan_mdb.c b/drivers/net/vxlan/vxlan_mdb.c
> index af7a0d7f95a57a17486a8ecc277b7bb9d921a061..9a9038ae90c18c5f0e4362b2b254b0c48dfdad0e 100644
> --- a/drivers/net/vxlan/vxlan_mdb.c
> +++ b/drivers/net/vxlan/vxlan_mdb.c
> @@ -1631,7 +1631,7 @@ struct vxlan_mdb_entry *vxlan_mdb_entry_skb_get(struct vxlan_dev *vxlan,
>
> switch (skb->protocol) {
> case htons(ETH_P_IP):
> - if (!pskb_may_pull(skb, sizeof(struct iphdr)))
> + if (!pskb_network_may_pull(skb, sizeof(struct iphdr)))
> return NULL;
> group.dst.sa.sa_family = AF_INET;
> group.dst.sin.sin_addr.s_addr = ip_hdr(skb)->daddr;
> @@ -1640,7 +1640,7 @@ struct vxlan_mdb_entry *vxlan_mdb_entry_skb_get(struct vxlan_dev *vxlan,
> break;
> #if IS_ENABLED(CONFIG_IPV6)
> case htons(ETH_P_IPV6):
> - if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
> + if (!pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))
> return NULL;
> group.dst.sa.sa_family = AF_INET6;
> group.dst.sin6.sin6_addr = ipv6_hdr(skb)->daddr;
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
prev parent reply other threads:[~2026-07-23 16:44 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-23 14:42 [PATCH net 0/5] vxlan: fixes for skb header pulling, cloning, and concurrency in TX path Eric Dumazet
2026-07-23 14:42 ` [PATCH net 1/5] vxlan: re-fetch eth header after route_shortcircuit() Eric Dumazet
2026-07-23 16:37 ` Vadim Fedorenko
2026-07-23 14:42 ` [PATCH net 2/5] vxlan: unclone skb head before modifying eth header in route_shortcircuit() Eric Dumazet
2026-07-23 14:42 ` [PATCH net 3/5] vxlan: use neigh_ha_snapshot() " Eric Dumazet
2026-07-23 16:41 ` Vadim Fedorenko
2026-07-23 14:42 ` [PATCH net 4/5] vxlan: use pskb_network_may_pull() " Eric Dumazet
2026-07-23 16:42 ` Vadim Fedorenko
2026-07-23 14:42 ` [PATCH net 5/5] vxlan: use pskb_network_may_pull() for transmit path header pulls Eric Dumazet
2026-07-23 16:43 ` Vadim Fedorenko [this message]
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