Vulnerability in Linux kernel (CVE-2025-68740)

Summary

Vulnerability in Linux kernel (CVE-2025-68740). Risk of unauthorized operations or information disclosure.

Original description

The description as published by the source.

In the Linux kernel, the following vulnerability has been resolved:

ima: Handle error code returned by ima_filter_rule_match()

In ima_match_rules(), if ima_filter_rule_match() returns -ENOENT due to
the rule being NULL, the function incorrectly skips the 'if (!rc)' check
and sets 'result = true'. The LSM rule is considered a match, causing
extra files to be measured by IMA.

This issue can be reproduced in the following scenario:
After unloading the SELinux policy module via 'semodule -d', if an IMA
measurement is triggered before ima_lsm_rules is updated,
in ima_match_rules(), the first call to ima_filter_rule_match() returns
-ESTALE. This causes the code to enter the 'if (rc == -ESTALE &&
!rule_reinitialized)' block, perform ima_lsm_copy_rule() and retry. In
ima_lsm_copy_rule(), since the SELinux module has been removed, the rule
becomes NULL, and the second call to ima_filter_rule_match() returns
-ENOENT. This bypasses the 'if (!rc)' check and results in a false match.

Call trace:
selinux_audit_rule_match+0x310/0x3b8
security_audit_rule_match+0x60/0xa0
ima_match_rules+0x2e4/0x4a0
ima_match_policy+0x9c/0x1e8
ima_get_action+0x48/0x60
process_measurement+0xf8/0xa98
ima_bprm_check+0x98/0xd8
security_bprm_check+0x5c/0x78
search_binary_handler+0x6c/0x318
exec_binprm+0x58/0x1b8
bprm_execve+0xb8/0x130
do_execveat_common.isra.0+0x1a8/0x258
__arm64_sys_execve+0x48/0x68
invoke_syscall+0x50/0x128
el0_svc_common.constprop.0+0xc8/0xf0
do_el0_svc+0x24/0…

Source: NIST National Vulnerability Database NVD

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2025-68740 has been found in Linux kernel.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2025-68740" on the vendor's site.

CVE-2025-68740 (Linux kernel)
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (unclassified) exists in Linux kernel.

📍 Affected scope

Check the vendor advisory for the affected versions of Linux kernel.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to the patched release per vendor advisory.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
Audit SBOM/dependencies for affected components.
```
資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
2
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2025-68740 linux-lts Fixed in: 6.1.161-r0
Debian DEBIAN-CVE-2025-68740 linux Fixed in: 5.10.249-1
Ubuntu UBUNTU-CVE-2025-68740 linux