UBUNTU-CVE-2021-3489
The eBPF RINGBUF bpf_ringbuf_reserve() function in the Linux kernel did not check that the allocated size was smaller than the ringbuf size, allowing an attacker to perform out-of-bounds writes within the kernel and therefore, arbitrary code execution. This issue was fixed via commit 4b81ccebaeee ("bpf, ringbuf: Deny reserve of buffers larger than ringbuf") (v5.13-rc4) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. It was introduced via 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it") (v5.8-rc1).
02 / AFFECTED SOFTWARE
Affected packages
23 explicit affected versions
6 explicit affected versions
10 explicit affected versions
44 explicit affected versions
16 explicit affected versions
4 explicit affected versions
38 explicit affected versions
13 explicit affected versions
12 explicit affected versions
43 explicit affected versions
10 explicit affected versions
7 explicit affected versions
9 explicit affected versions
17 explicit affected versions
11 explicit affected versions
6 explicit affected versions
7 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
The eBPF RINGBUF bpf_ringbuf_reserve() function in the Linux kernel did not check that the allocated size was smaller than the ringbuf size, allowing an attacker to perform out-of-bounds writes within the kernel and therefore, arbitrary code execution. This issue was fixed via commit 4b81ccebaeee ("bpf, ringbuf: Deny reserve of buffers larger than ringbuf") (v5.13-rc4) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. It was introduced via 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it") (v5.8-rc1).
05 / REFERENCES
Further evidence
- https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=4b81ccebaeee885ab1aa1438133f2991e3a2b6ea
- https://ubuntu.com/security/CVE-2021-3489
- https://ubuntu.com/security/notices/USN-4948-1
- https://ubuntu.com/security/notices/USN-4949-1
- https://ubuntu.com/security/notices/USN-4950-1
- https://www.cve.org/CVERecord?id=CVE-2021-3489
- https://www.openwall.com/lists/oss-security/2021/05/11/10