6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Antoine Tenart [ Upstream commit 1f73a56f986005f0bc64ed23873930e2ee4f5911 ] Neither sock4 nor sock6 pointers are guaranteed to be non-NULL in vxlan_xmit_one, e.g. if the iface is brought down. This can lead to the following NULL dereference: BUG: kernel NULL pointer dereference, address: 0000000000000010 Oops: Oops: 0000 [#1] SMP NOPTI RIP: 0010:vxlan_xmit_one+0xbb3/0x1580 Call Trace: vxlan_xmit+0x429/0x610 dev_hard_start_xmit+0x55/0xa0 __dev_queue_xmit+0x6d0/0x7f0 ip_finish_output2+0x24b/0x590 ip_output+0x63/0x110 Mentioned commits changed the code path in vxlan_xmit_one and as a side effect the sock4/6 pointer validity checks in vxlan(6)_get_route were lost. Fix this by adding back checks. Since both commits being fixed were released in the same version (v6.7) and are strongly related, bundle the fixes in a single commit. Reported-by: Liang Li Fixes: 6f19b2c136d9 ("vxlan: use generic function for tunnel IPv4 route lookup") Fixes: 2aceb896ee18 ("vxlan: use generic function for tunnel IPv6 route lookup") Cc: Beniamino Galvani Signed-off-by: Antoine Tenart Reviewed-by: Ido Schimmel Tested-by: Ido Schimmel Link: https://patch.msgid.link/20251126102627.74223-1-atenart@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/vxlan/vxlan_core.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c index f612def46c3c4..567793aea4a21 100644 --- a/drivers/net/vxlan/vxlan_core.c +++ b/drivers/net/vxlan/vxlan_core.c @@ -2402,7 +2402,7 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, int addr_family; __u8 tos, ttl; int ifindex; - int err; + int err = 0; u32 flags = vxlan->cfg.flags; bool use_cache; bool udp_sum = false; @@ -2504,11 +2504,16 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, rcu_read_lock(); if (addr_family == AF_INET) { - struct vxlan_sock *sock4 = rcu_dereference(vxlan->vn4_sock); + struct vxlan_sock *sock4; struct rtable *rt; __be16 df = 0; __be32 saddr; + sock4 = rcu_dereference(vxlan->vn4_sock); + if (unlikely(!sock4)) { + goto tx_error; + } + if (!ifindex) ifindex = sock4->sock->sk->sk_bound_dev_if; @@ -2576,9 +2581,14 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, src_port, dst_port, xnet, !udp_sum); #if IS_ENABLED(CONFIG_IPV6) } else { - struct vxlan_sock *sock6 = rcu_dereference(vxlan->vn6_sock); + struct vxlan_sock *sock6; struct in6_addr saddr; + sock6 = rcu_dereference(vxlan->vn6_sock); + if (unlikely(!sock6)) { + goto tx_error; + } + if (!ifindex) ifindex = sock6->sock->sk->sk_bound_dev_if; -- 2.53.0