vxlan: use one headroom snapshot for neighbour replies (Linux Linux)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.21 % · percentile 11 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- Received
Description
In the Linux kernel, the following vulnerability has been resolved: vxlan: use one headroom snapshot for neighbour replies vxlan_na_create() samples LL_RESERVED_SPACE() to size the reply skb and then samples it again to reserve headroom. A concurrent vxlan_changelink() can update needed_headroom between the two reads, creating a TOCTOU race. The second value can exceed the allocation and make the Ethernet header write out of bounds. The race is reproducible on the unpatched kernel. It occurred when vxlan_na_create() generated a neighbour reply while vxlan_changelink() changed the link headroom. KASAN caught a four-byte write two bytes beyond a 704-byte skbuff_small_head allocation. Snapshot the headroom once and use that value for both allocation and reservation.
References
- https://git.kernel.org/stable/c/e3e24f4c434c56952412f875b834aa9daaa4fb15
- https://git.kernel.org/stable/c/9ed5a548b42d46e6968a46b67ca8a8e49b12a5a1
- https://git.kernel.org/stable/c/fcaf456092dc86fd5b0b523ac27ec0d114066931
- https://git.kernel.org/stable/c/45a67662bf8ce3aa5643accf98d328dfbb47eaf6
- https://git.kernel.org/stable/c/315d42ca39f69846662961c25dcf2bb07c350d14
- https://git.kernel.org/stable/c/a3c5eb6e382dd426a5e7eb08608897ed57167ff7
- https://git.kernel.org/stable/c/ff022fd9d0f0282c575e11778b96bd1b637503eb
- https://git.kernel.org/stable/c/481506a756dcd828ef42391cb08f38d8d96d38fc
European references
- ENISA EUVD · EUVD-2026-103613
- GCVE · GCVE-0-2026-98568
CERT-FR advisories
- CERTFR-2026-AVI-1375 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
Affected products
| Product | Versions |
|---|---|
| Linux · Linux | affected 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa < e3e24f4c434c56952412f875b834aa9daaa4fb15 ; affected 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa < 9ed5a548b42d46e6968a46b67ca8a8e49b12a5a1 ; affected 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa < fcaf456092dc86fd5b0b523ac27ec0d114066931 ; affected 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa < 45a67662bf8ce3aa5643accf98d328dfbb47eaf6 ; affected 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa < 315d42ca39f69846662961c25dcf2bb07c350d14 ; affected 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa < a3c5eb6e382dd426a5e7eb08608897ed57167ff7 |
| Linux · Linux | affected 3.14 ; unaffected 0 < 3.14 ; unaffected 5.10.273 ≤ 5.10.* ; unaffected 5.15.224 ≤ 5.15.* ; unaffected 6.1.191 ≤ 6.1.* ; unaffected 6.6.158 ≤ 6.6.* |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |