The bpf verifier in the Linux kernel did not properly handle mod32 destination register truncation when the source register was known to be 0. A local attacker with the ability to load bpf programs could use this gain out-of-bounds reads in kernel memory leading to information disclosure (kernel memory), and possibly out-of-bounds writes that could potentially lead to code execution. This issue was addressed in the upstream kernel in commit 9b00f1b78809 ("bpf: Fix truncation handling for mod32 dst reg wrt zero") and in Linux stable kernels 5.11.2, 5.10.19, and 5.4.101.

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Source ID Title
Debian DLA Debian DLA DLA-2785-1 linux-4.19 security update
EUVD EUVD EUVD-2021-26770 The bpf verifier in the Linux kernel did not properly handle mod32 destination register truncation when the source register was known to be 0. A local attacker with the ability to load bpf programs could use this gain out-of-bounds reads in kernel memory leading to information disclosure (kernel memory), and possibly out-of-bounds writes that could potentially lead to code execution. This issue was addressed in the upstream kernel in commit 9b00f1b78809 ("bpf: Fix truncation handling for mod32 dst reg wrt zero") and in Linux stable kernels 5.11.2, 5.10.19, and 5.4.101.
Ubuntu USN Ubuntu USN USN-4887-1 Linux kernel vulnerabilities
Fixes

Solution

Apply or update to a kernel that contains the commit 9b00f1b78809 ("bpf: Fix truncation handling for mod32 dst reg wrt zero").


Workaround

No workaround given by the vendor.

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cve-icon MITRE

Status: PUBLISHED

Assigner: canonical

Published:

Updated: 2024-09-16T17:27:58.788Z

Reserved: 2021-03-16T00:00:00

Link: CVE-2021-3444

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2021-03-23T18:15:13.627

Modified: 2024-11-21T06:21:32.220

Link: CVE-2021-3444

cve-icon Redhat

Severity : Moderate

Publid Date: 2021-02-13T00:00:00Z

Links: CVE-2021-3444 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses