Bug 2363730 (CVE-2023-53055)

Summary: CVE-2023-53055 kernel: fscrypt: destroy keyring after security_sb_delete()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: low    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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Description OSIDB Bzimport 2025-05-02 16:03:32 UTC 
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.
Comment 1 Avinash Hanwate 2025-05-05 04:44:21 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025050207-CVE-2023-53055-afd1@gregkh/T