CVE-2021-3489

About vulnerability

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).

Affected product:

AlmaLinux 8 , CentOS 6 , CentOS 6 plus , CentOS 7 , CentOS 7 plus , CentOS 8 , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux OS 6 , CloudLinux OS 6h , CloudLinux OS 7 , CloudLinux OS 7h , CloudLinux OS 8 , Debian 10 , Debian 10 cloud , Debian 9 , Endurance 7 eig 3.10 , OpenVZ 6 , Proxmox VE 5 , Proxmox VE 6 , RHEL 6 , RHEL 7 , RHEL 8 , Rocky Linux 8 , Scientific 6 , Ubuntu 14.04 , Ubuntu 14.04 ESM , Ubuntu 16.04 , Ubuntu 16.04 ESM , Ubuntu 18.04 , Ubuntu 20.04

Affected packages:

kernel @ - (+58 more)

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).