In the Linux kernel before 5.15.3, fs/quota/quota_tree.c does not validate the block number in the quota tree (on disk). This can, for example, lead to a kernel/locking/rwsem.c use-after-free if there is a corrupted quota file. CREATE(Triage):(User=admin) CVE-2021-45868 (https://nvd.nist.gov/vuln/detail/CVE-2021-45868)