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Oracle Linux: (CVE-2021-3489) ELSA-2021-4356: kernel security, bug fix, and enhancement update

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Oracle Linux: (CVE-2021-3489) ELSA-2021-4356: kernel security, bug fix, and enhancement update

Severity
7
CVSS
(AV:L/AC:L/Au:N/C:C/I:C/A:C)
Published
05/11/2021
Created
11/20/2021
Added
11/18/2021
Modified
11/18/2021

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).

Solution(s)

  • oracle-linux-upgrade-kernel

References

  • ELSA-2021-4356
  • USN-4948-1
  • USN-4949-1
  • USN-4950-1
  • CVE-2021-3489

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