Detections
Analytics
CVE-2021-3489
high
Description
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).
References
https://www.zerodayinitiative.com/advisories/ZDI-21-590/
https://www.openwall.com/lists/oss-security/2021/05/11/10
https://ubuntu.com/security/notices/USN-4950-1
https://ubuntu.com/security/notices/USN-4949-1