CVE-2025-38396: fs: export anon_inode_make_secure_inode() and fix secretmem LSM bypass

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-07-25 · updated 2026-07-30

Description

In the Linux kernel, the following vulnerability has been resolved: fs: export anon_inode_make_secure_inode() and fix secretmem LSM bypass Export anon_inode_make_secure_inode() to allow KVM guest_memfd to create anonymous inodes with proper security context. This replaces the current pattern of calling alloc_anon_inode() followed by inode_init_security_anon() for creating security context manually. This change also fixes a security regression in secretmem where the S_PRIVATE flag was not cleared after alloc_anon_inode(), causing LSM/SELinux checks to be bypassed for secretmem file descriptors. As guest_memfd currently resides in the KVM module, we need to export this symbol for use outside the core kernel. In the future, guest_memfd might be moved to core-mm, at which point the symbols no longer would have to be exported. When/if that happens is still unclear.

Affected products

Debian Linux: 11.0
Linux kernel: from 6.0 before 6.1.146; from 6.2 before 6.6.97; from 6.7 before 6.12.37; from 6.13 before 6.15.6; 6.16-rc1, 6.16-rc2, 6.16-rc3, 6.16-rc4 — fixed in 6.1.146, 6.12.37, 6.15.6, 6.6.97

How to fix

Upgrade to a fixed version: Linux kernel 6.1.146, 6.12.37, 6.15.6, 6.6.97. Check the vendor advisory for mitigations.

References

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