{"id":"CVE-2021-4001","details":"A race condition was found in the Linux kernel's ebpf verifier between bpf_map_update_elem and bpf_map_freeze due to a missing lock in kernel/bpf/syscall.c. In this flaw, a local user with a special privilege (cap_sys_admin or cap_bpf) can modify the frozen mapped address space. This flaw affects kernel versions prior to 5.16 rc2.","modified":"2026-03-13T05:08:04.426290Z","published":"2022-01-21T19:15:09.703Z","related":["MGASA-2021-0538","MGASA-2021-0539","SUSE-SU-2022:0056-1","SUSE-SU-2022:0079-1","SUSE-SU-2022:0131-1","SUSE-SU-2022:0181-1","SUSE-SU-2022:0197-1","SUSE-SU-2022:0978-1","SUSE-SU-2022:0984-1","openSUSE-SU-2022:0056-1","openSUSE-SU-2022:0131-1"],"references":[{"type":"FIX","url":"https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=353050be4c19e102178ccc05988101887c25ae53"},{"type":"FIX","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2025645"}],"affected":[{"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2021-4001.json","unresolved_ranges":[{"events":[{"introduced":"0"},{"last_affected":"5.15"}]},{"events":[{"introduced":"0"},{"last_affected":"5.16-rc1"}]}]}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N"}]}