Description
In the Linux kernel, the following vulnerability has been resolved: vxlan: Fix potential null-ptr-deref in vxlan_gro_prepare_receive(). udp_tunnel_sock_release() could set sk->sk_user_data to NULL while vxlan_gro_prepare_receive() is running. Let's check if rcu_dereference_sk_user_data() is NULL after skb_gro_remcsum_init().
References8
- git.kernel.org/stable/c/022af89207fcc992ec5c712c14e2e018c335eb1e
- git.kernel.org/stable/c/08f40c0d23c67c3aa4224c3311e134999c721fb4
- git.kernel.org/stable/c/30a45c0bffdd62350261e2f2689fdba426a33578
- git.kernel.org/stable/c/4a8cde6f7281ea2c4c290f9ad9923b3631defceb
- git.kernel.org/stable/c/9c58c729d32e7cea5772cc44929c6cd61e5a31cd
- git.kernel.org/stable/c/a3104cc1fed994519538301efcaab175f9af6008
- git.kernel.org/stable/c/ef44dac2a37f86eeae6b88ed10a6d60b35387dfd
- git.kernel.org/stable/c/f79c80f173fda9545b220c1f094b65fc06c252d0
Metrics
- CVSS 3.1
-
9.8
CRITICAL
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 1% percentile: 44 · as of 11 November 2026
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.