CVE-2022-50536

Description

A reference-count flaw was found in the Linux kernel Berkeley Packet Filter (BPF) sockmap implementation. When processing messages with remaining data, the same Transmission Control Protocol (TCP) socket reference could be released more than once. A local user running BPF sockmap programs could use this flaw to trigger a use-after-free and crash the system, resulting in a denial of service.

Statement

The flaw arises because the verdict state was not reset at boundaries where additional message data arrives, causing the same socket reference to be dropped more than once. The fix resets the internal verdict state when handling continued data, preventing double release.

Mitigation

To mitigate this issue, prevent module bpf from being loaded.
 Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score5.57.87.8
Attack VectorLocalLocalLocal
Attack ComplexityLowLowLow
Privileges RequiredLowLowLow
User InteractionNoneNoneNone
ScopeUnchangedUnchangedUnchanged
ConfidentialityNoneHighHigh
Integrity ImpactNoneHighHigh
Availability ImpactHighHighHigh

Vector

Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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