CVE-2026-31663 PUBLISHED

xfrm: hold dev ref until after transport_finish NF_HOOK

Assigner: Linux
Reserved: 09.03.2026 Published: 24.04.2026 Updated: 24.04.2026

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.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from acf568ee859f098279eadf551612f103afdacb4e to 0f451b43c88bf2b9c038b414be580efee42e031b (excl.)
  • affected from acf568ee859f098279eadf551612f103afdacb4e to 5002beda5cac69d522dc54da0d5d463ed9c963d2 (excl.)
  • affected from acf568ee859f098279eadf551612f103afdacb4e to 1c428b03840094410c5fb6a5db30640486bbbfcb (excl.)
  • Version 69895c5ea0ca2e8d7de1e6d36965d0ab9730787f is affected
  • Version 833760100588acfb267dac4d6a02ab9931237739 is affected
  • Version e095ecaec6d94aa2156cceb98a85d409b51190f3 is affected
Vendor Linux
Product Linux
Versions Default: affected
  • Version 4.15 is affected
  • unaffected from 0 to 4.15 (excl.)
  • unaffected from 6.18.23 to 6.18.* (incl.)
  • unaffected from 6.19.13 to 6.19.* (incl.)
  • unaffected from 7.0 to * (incl.)

References