CVE-2023-53055: fscrypt: destroy keyring after security_sb_delete()

Severity: medium (CVSS 5.5 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: 2025-05-02 · updated 2026-06-17
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: fscrypt: destroy keyring after security_sb_delete() fscrypt_destroy_keyring() must be called after all potentially-encrypted inodes were evicted; otherwise it cannot safely destroy the keyring. Since inodes that are in-use by the Landlock LSM don't get evicted until security_sb_delete(), this means that fscrypt_destroy_keyring() must be called *after* security_sb_delete(). This fixes a WARN_ON followed by a NULL dereference, only possible if Landlock was being used on encrypted files.

Affected products

Linux kernel: from 5.10.154 before 5.11; from 5.15.78 before 5.15.105; from 6.0.8 before 6.1.22; from 6.2 before 6.2.9; 6.3-rc1, 6.3-rc2, 6.3-rc3 — fixed in 5.11, 5.15.105, 6.1.22, 6.2.9

How to fix

Upgrade to a fixed version: Linux kernel 5.11, 5.15.105, 6.1.22, 6.2.9. Check the vendor advisory for mitigations.

References

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