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Red Hat: CVE-2021-33200: CVE-2021-33200 kernel: out-of-bounds reads and writes due to enforcing incorrect limits for pointer arithmetic operations by BPF verifier (Multiple Advisories)

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Red Hat: CVE-2021-33200: CVE-2021-33200 kernel: out-of-bounds reads and writes due to enforcing incorrect limits for pointer arithmetic operations by BPF verifier (Multiple Advisories)

Severity
7
CVSS
(AV:L/AC:L/Au:N/C:C/I:C/A:C)
Published
05/27/2021
Created
11/11/2021
Added
11/10/2021
Modified
03/13/2024

Description

kernel/bpf/verifier.c in the Linux kernel through 5.12.7 enforces incorrect limits for pointer arithmetic operations, aka CID-bb01a1bba579. This can be abused to perform out-of-bounds reads and writes in kernel memory, leading to local privilege escalation to root. In particular, there is a corner case where the off reg causes a masking direction change, which then results in an incorrect final aux->alu_limit.

Solution(s)

  • redhat-upgrade-kernel
  • redhat-upgrade-kernel-rt

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