CVE-2021-46974

Severity CVSS v4.0:

Pending analysis

Type:

Unavailable / Other

Publication date:

27/02/2024

Last modified:

09/01/2025

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix masking negation logic upon negative dst register The negation logic for the case where the off_reg is sitting in the dst register is not correct given then we cannot just invert the add to a sub or vice versa. As a fix, perform the final bitwise and-op unconditionally into AX from the off_reg, then move the pointer from the src to dst and finally use AX as the source for the original pointer arithmetic operation such that the inversion yields a correct result. The single non-AX mov in between is possible given constant blinding is retaining it as it&#39;s not an immediate based operation.

Impact

Vector 3.x

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS v3.1 Severity and Metrics:

Base Score: 5.50 MEDIUM
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): None
Availability (A): High

Base Score 3.x

5.50

Severity 3.x

MEDIUM

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:o:linux:linux_kernel::::::::	4.14.113 (including)	4.14.233 (excluding)
cpe:2.3:o:linux:linux_kernel::::::::	4.19.19 (including)	4.19.190 (excluding)
cpe:2.3:o:linux:linux_kernel::::::::	5.0 (including)	5.4.117 (excluding)
cpe:2.3:o:linux:linux_kernel::::::::	5.5 (including)	5.10.35 (excluding)
cpe:2.3:o:linux:linux_kernel::::::::	5.11 (including)	5.11.19 (excluding)
cpe:2.3:o:linux:linux_kernel::::::::	5.12 (including)	5.12.2 (excluding)

To consult the complete list of CPE names with products and versions, see this page

CVE-2021-46974

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools