CVE-2026-46027: net/smc: avoid early lgr access in smc_clc_wait_msg

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-27 · updated 2026-10-19
Weakness: CWE-617

Description

In the Linux kernel, the following vulnerability has been resolved: net/smc: avoid early lgr access in smc_clc_wait_msg A CLC decline can be received while the handshake is still in an early stage, before the connection has been associated with a link group. The decline handling in smc_clc_wait_msg() updates link-group level sync state for first-contact declines, but that state only exists after link group setup has completed. Guard the link-group update accordingly and keep the per-socket peer diagnosis handling unchanged. This preserves the existing sync_err handling for established link-group contexts and avoids touching link-group state before it is available.

Affected products

Linux kernel: from 4.11 before 5.10.258; from 5.11 before 5.15.209; from 5.16 before 6.1.175; from 6.2 before 6.6.140; from 6.7 before 6.12.86; from 6.13 before 6.18.27 — fixed in 5.10.258, 5.15.209, 6.1.175, 6.12.86, 6.18.27, 6.6.140

How to fix

Upgrade to a fixed version: Linux kernel 5.10.258, 5.15.209, 6.1.175, 6.12.86. Check the vendor advisory for mitigations.

References

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