CVE-2026-31663
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.12%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.12% probability · 2th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-826
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/0f451b43c88bf2b9c038b414be580efee42e031bPatch
- https://git.kernel.org/stable/c/1c428b03840094410c5fb6a5db30640486bbbfcbPatch
- https://git.kernel.org/stable/c/4236c30b437b80f673b9e08c8fae38b8d471ac9e
- https://git.kernel.org/stable/c/5002beda5cac69d522dc54da0d5d463ed9c963d2Patch
- https://access.redhat.com/security/cve/CVE-2026-31663
- https://bugzilla.redhat.com/show_bug.cgi?id=2461462
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31663.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.