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VulnerabilityPublished Updated

CVE-2026-90235: Linux kernel · sunrpc: xprtsock: annotate shared socket callbacks with READ_ONCE/WRITE_ONCE

Affects Linux kernelSource GCVE Database

0

Not known to be exploited · CVSS 9.8 Critical.

Data as of 28 Oct 2026, 01:12 UTC

CVSS 3.1 base score
9.8Critical
How severe the flaw is on the 0–10 CVSS scale.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 17 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Affected software

ProductAffectedFixed in
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-5.5 – 7.0.0-38.38
23 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-1002.2 – 7.0.0-1014.14
15 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-1003.3 – 7.0.0-1017.17
15 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threatsAffected
  • 7.0.0-1003.3 – 7.0.0-1016.16
9 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-1002.2 – 7.0.0-1014.14
13 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threatsAffected
  • 7.0.0-1002.3 – 7.0.0-1008.9
6 affected builds
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

In the Linux kernel, the following vulnerability has been resolved: sunrpc: xprtsock: annotate shared socket callbacks with READ_ONCE/WRITE_ONCE xprtsock replaces and restores sk->sk_data_ready and sk->sk_write_space on live sockets with plain stores, and xs_udp_do_set_buffer_size() invokes sk->sk_write_space via a plain load. These callback pointers are shared with generic socket and protocol paths that may read or invoke them concurrently, so xprtsock needs the same READ_ONCE()/WRITE_ONCE() callback visibility contract that the validated 4022 family applied elsewhere. When SUNRPC takes over an AF_LOCAL, UDP, or TCP socket and later restores the lower-socket callbacks during teardown, another CPU may still hold an earlier callback snapshot. The plain replace/restore pattern leaves the same visibility hole as the validated 4022 family, so a stale snapshot can still invoke xs_data_ready() or xs_udp_write_space() after the live callback fields have already been restored to the lower-socket handlers. Use WRITE_ONCE() for the shared sk_data_ready and sk_write_space stores in xs_local_finish_connecting(), xs_udp_finish_connecting(), xs_tcp_finish_connecting(), and xs_restore_old_callbacks(). Use READ_ONCE() for the direct sk_write_space invocation in xs_udp_do_set_buffer_size(). This matches the required callback visibility contract while leaving adjacent sk_state_change and sk_error_report handling unchanged.

References

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