smc: Use __sk_dst_get() and dst_dev_rcu() in in smc_clc_prfx_set(). (CVE-2025-40139) | HOL Guard CVE

High · CVSS 7.8CVE-2025-40139

smc: Use __sk_dst_get() and dst_dev_rcu() in in smc_clc_prfx_set().

Answer in brief

CVE-2025-40139 records a High severity (CVSS 7.8) vulnerability in smc: Use __sk_dst_get() and dst_dev_rcu() in in smc_clc_prfx_set().. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Nov 12, 2025Updated Sep 2, 2026Source checked Sep 19, 2026First seen by HOL Aug 5, 2026Material review Sep 2, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.8
Exploitation: Not marked as known exploited
Affected software: 3 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=a046d57da19f812216f393e7c535f5858f793ac3 <0736993bfe5c7a9c744ae3fac62d769dfdae54e1 \|\| >=a046d57da19f812216f393e7c535f5858f793ac3 <935d783e5de9b64587f3adb25641dd8385e64ddb	0736993bfe5c7a9c744ae3fac62d769dfdae54e1, 935d783e5de9b64587f3adb25641dd8385e64ddb
Linux/Linuxgeneric	4.11	Not reported
Linux/Linuxgeneric	>=a046d57da19f812216f393e7c535f5858f793ac3 <5a2fccc4b32c13ddde3676f9e15e1a9baa7d6fde \|\| >=a046d57da19f812216f393e7c535f5858f793ac3 <80d1fd39f4e37d836655e9f7ffccaf78925049bf \|\| >=a046d57da19f812216f393e7c535f5858f793ac3 <956c57daba55cf9ed25d9f2512883b8a1a927599 \|\| >=a046d57da19f812216f393e7c535f5858f793ac3 <0736993bfe5c7a9c744ae3fac62d769dfdae54e1 \|\| >=a046d57da19f812216f393e7c535f5858f793ac3 <935d783e5de9b64587f3adb25641dd8385e64ddb	5a2fccc4b32c13ddde3676f9e15e1a9baa7d6fde, 80d1fd39f4e37d836655e9f7ffccaf78925049bf, 956c57daba55cf9ed25d9f2512883b8a1a927599, 0736993bfe5c7a9c744ae3fac62d769dfdae54e1, 935d783e5de9b64587f3adb25641dd8385e64ddb

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 0736993bfe5c7a9c744ae3fac62d769dfdae54e1; Linux/Linux to 5a2fccc4b32c13ddde3676f9e15e1a9baa7d6fde if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Nov 12, 2025
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 2, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 5, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: smc: Use __sk_dst_get() and dst_dev_rcu() in in smc_clc_prfx_set(). smc_clc_prfx_set() is called during connect() and not under RCU nor RTNL. Using sk_dst_get(sk)->dev could trigger UAF. Let's use __sk_dst_get() and dev_dst_rcu() under rcu_read_lock() after kernel_getsockname(). Note that the returned value of smc_clc_prfx_set() is not used in the caller. While at it, we change the 1st arg of smc_clc_prfx_set[46]_rcu() not to touch dst there.

Quoted source text, attributed separately from HOL analysis.