Linux vulnerability

What happened

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.

Affected versions

Linux: acf568ee859f098279eadf551612f103afdacb4e through before 4236c30b437b80f673b9e08c8fae38b8d471ac9e (git); acf568ee859f098279eadf551612f103afdacb4e through before 0f451b43c88bf2b9c038b414be580efee42e031b (git); acf568ee859f098279eadf551612f103afdacb4e through before 5002beda5cac69d522dc54da0d5d463ed9c963d2 (git); acf568ee859f098279eadf551612f103afdacb4e through before 1c428b03840094410c5fb6a5db30640486bbbfcb (git); 69895c5ea0ca2e8d7de1e6d36965d0ab9730787f (git); 833760100588acfb267dac4d6a02ab9931237739 (git); e095ecaec6d94aa2156cceb98a85d409b51190f3 (git); 3.2.100 through before 3.3 (semver); 3.16.55 through before 3.17 (semver); 4.14.24 through before 4.15 (semver); 4.15 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

• Apply vendor-provided updates or mitigations.
• Review affected product exposure and access logs.