CVE-2023-53662

A memory leak flaw was found in the Linux kernel's ext4 filesystem in the filename casefolding error paths. A local user can trigger this issue by performing directory operations on ext4 filesystems with casefolding enabled when filename setup or lookup operations fail, causing the crypto_buf.name field from the fscrypt_name structure to remain allocated. This results in permanent memory leaks leading to resource exhaustion and denial of service.

The ext4_fname_setup_filename and ext4_fname_prepare_lookup functions handle filename preparation for encrypted and casefolded filesystems. When casefolding operations fail, the error paths return immediately without freeing the crypto_buf.name buffer that was allocated earlier during fscrypt setup. Since these functions are called for every filename operation on casefolded ext4 filesystems, repeated failures can accumulate significant memory leaks.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.