CVE-2026-31684
MEDIUMAttack Surface
CVSS Vector Breakdown
Description
In the Linux kernel, the following vulnerability has been resolved: net: sched: act_csum: validate nested VLAN headers tcf_csum_act() walks nested VLAN headers directly from skb->data when an skb still carries in-payload VLAN tags. The current code reads vlan->h_vlan_encapsulated_proto and then pulls VLAN_HLEN bytes without first ensuring that the full VLAN header is present in the linear area. If only part of an inner VLAN header is linearized, accessing h_vlan_encapsulated_proto reads past the linear area, and the following skb_pull(VLAN_HLEN) may violate skb invariants. Fix this by requiring pskb_may_pull(skb, VLAN_HLEN) before accessing and pulling each nested VLAN header. If the header still is not fully available, drop the packet through the existing error path.
Affected Software (19)
| Vendor | Product | Version |
|---|---|---|
| Linux | Linux | 2ecba2d1e45b24620a7c3df9531895cf68d5dec6 < 0410c619e86551677fb79887a38eccad3f5a0725 |
| Linux | Linux | 2ecba2d1e45b24620a7c3df9531895cf68d5dec6 < 886469b6455611a511aa6013e957e15e50577513 |
| Linux | Linux | 2ecba2d1e45b24620a7c3df9531895cf68d5dec6 < 46c07ad50fa2f4ba7663ee1b72b75ad7ad45cf09 |
| Linux | Linux | 2ecba2d1e45b24620a7c3df9531895cf68d5dec6 < eb3765b90eb8f2a3d6310a80c14a9e57ec4267a2 |
| Linux | Linux | 2ecba2d1e45b24620a7c3df9531895cf68d5dec6 < a69738efea0996d05a3c7d2178551b891744df1b |
| Linux | Linux | 2ecba2d1e45b24620a7c3df9531895cf68d5dec6 < ec4930979b3f7bbeb7af5744599fc6603a4dba62 |
| Linux | Linux | 2ecba2d1e45b24620a7c3df9531895cf68d5dec6 < 3d165d975305cf76ff0b10a3c798fb31e5f5f9a5 |
| Linux | Linux | 2ecba2d1e45b24620a7c3df9531895cf68d5dec6 < c842743d073bdd683606cb414eb0ca84465dd834 |
| Linux | Linux | 3764bfae5056e95617b6ee074129297e11710886 |
| Linux | Linux | 4.19.99 < 4.20 |
| Linux | Linux | 5.1 |
| linux | linux_kernel | 4.19.99 – 4.20 |
| linux | linux_kernel | 7.0 |
| linux | linux_kernel | 7.0 |
| linux | linux_kernel | 7.0 |
| linux | linux_kernel | 7.0 |
| linux | linux_kernel | 7.0 |
| linux | linux_kernel | 7.0 |
| linux | linux_kernel | 7.0 |