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CVE PROGRAM SOURCE RECORDUnscored

CVE-2026-46193

xfrm: ah: account for ESN high bits in async callbacks

Read JSON ↗CVE.org ↗
Status
Published
Published
Updated
Assigning organization
Linux

Description

In the Linux kernel, the following vulnerability has been resolved: xfrm: ah: account for ESN high bits in async callbacks AH allocates its temporary auth/ICV layout differently when ESN is enabled: the async ahash setup appends a 4-byte seqhi slot before the ICV or auth_data area, but the async completion callbacks still reconstruct the temporary layout as if seqhi were absent. With an async AH implementation selected, that makes AH copy or compare the wrong bytes on both the IPv4 and IPv6 paths. In UML repro on IPv4 AH with ESN and forced async hmac(sha1), ping fails with 100% packet loss, and the callback logs show the pre-fix drift: ah4 output_done: esn=1 err=0 icv_off=20 expected_off=24 ah4 input_done: esn=1 auth_off=20 expected_auth_off=24 icv_off=32 expected_icv_off=36 Reconstruct the callback-side layout the same way the setup path built it by skipping the ESN seqhi slot before locating the saved auth_data or ICV. Per RFC 4302, the ESN high-order 32 bits participate in the AH ICV computation, so the async callbacks must account for the seqhi slot. Post-fix, the same IPv4 AH+ESN+forced-async-hmac(sha1) UML repro shows the corrected offset (ah4 output_done: esn=1 err=0 icv_off=24 expected_off=24) and ping succeeds; net/ipv4/ah4.o and net/ipv6/ah6.o build clean at W=1. IPv6 AH+ESN was not exercised at runtime, and the change has not been tested against a real async hardware AH engine.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • d4d573d0334d07341beffdcf97e2b85d3955d8ae to < ec406c26c97594124e79d14516b729a8d5dced62affected
  • d4d573d0334d07341beffdcf97e2b85d3955d8ae to < 1dae77078ceb4bab833f7a4935f05c5b8c97b9baaffected
  • d4d573d0334d07341beffdcf97e2b85d3955d8ae to < 0555d4f526232b3c9e3afbcd490c0c0793aefec6affected
  • d4d573d0334d07341beffdcf97e2b85d3955d8ae to < 729899a2aa8bda7844be0cdcd3b470f11b912edaaffected
  • d4d573d0334d07341beffdcf97e2b85d3955d8ae to < 7db99a09b3bc87268287bc7ab5f2e7f382b5ad87affected
  • d4d573d0334d07341beffdcf97e2b85d3955d8ae to < 2ffaa7a94f9a4d22724364a1821735a0231d9f8daffected
  • d4d573d0334d07341beffdcf97e2b85d3955d8ae to < ec54093e6a8f87e800bb6aa15eb7fc1e33faa524affected

Linux Linux

Default version status: affected

  • 3.15affected
  • 0 to < 3.15unaffected
  • 5.15.210 to ≤ 5.15.*unaffected
  • 6.1.176 to ≤ 6.1.*unaffected
  • 6.6.140 to ≤ 6.6.*unaffected
  • 6.12.88 to ≤ 6.12.*unaffected
  • 6.18.30 to ≤ 6.18.*unaffected
  • 7.0.7 to ≤ 7.0.*unaffected
  • 7.1 to ≤ *unaffected

References