CVE-2026-31663
Published: April 25, 2026Last modified: July 6, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: xfrm: hold dev ref until after transport_finish NF_HOOK After async crypto completes, xfrm_input_resume() calls dev_put() immediately on re-entry before the skb reaches transport_finish. The skb->dev pointer is then used inside NF_HOOK and its okfn, which can race with device teardown. Remove the dev_put from the async resumption entry and instead drop the reference after the NF_HOOK call in transport_finish, using a saved device pointer since NF_HOOK may consume the skb. This covers NF_DROP, NF_QUEUE and NF_STOLEN paths that skip the okfn. For non-transport exits (decaps, gro, drop) and secondary async return points, release the reference inline when async is set.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.8 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Vulnerable (6.1.168-r0) |
| 25 LTS | linux-lts | Fixed (6.12.95-r0) | |
| Stream | linux-lts | Fixed (6.18.35-r1) |
References
- https://access.redhat.com/security/cve/CVE-2026-31663
- https://bugzilla.redhat.com/show_bug.cgi?id=2461462
- https://git.kernel.org/stable/c/0f451b43c88bf2b9c038b414be580efee42e031b
- https://git.kernel.org/stable/c/1c428b03840094410c5fb6a5db30640486bbbfcb
- https://git.kernel.org/stable/c/4236c30b437b80f673b9e08c8fae38b8d471ac9e
- https://git.kernel.org/stable/c/5002beda5cac69d522dc54da0d5d463ed9c963d2
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31663.json