UBUNTU-CVE-2021-4001
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.
02 / AFFECTED SOFTWARE
Affected packages
29 explicit affected versions
77 explicit affected versions
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9 explicit affected versions
11 explicit affected versions
31 explicit affected versions
6 explicit affected versions
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50 explicit affected versions
12 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
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.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/353050be4c19e102178ccc05988101887c25ae53
- https://ubuntu.com/security/CVE-2021-4001
- https://ubuntu.com/security/notices/USN-5207-1
- https://ubuntu.com/security/notices/USN-5265-1
- https://ubuntu.com/security/notices/USN-5278-1
- https://ubuntu.com/security/notices/USN-6417-1
- https://www.cve.org/CVERecord?id=CVE-2021-4001