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CVE-2026-72401

kernel: bpf: Fix insn_aux_data leak on verifier err_free_env path

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Severity

Low

Red Hat Product Security

5.5

CVSS 3.1

Review impact separately from score.

Published · August 15, 2026

Updated · October 17, 2026

Description

A flaw was found in the Linux kernel's Berkeley Packet Filter (BPF) verifier. This vulnerability occurs when the bpf_check() function fails to allocate certain resources, leading to a memory leak of insn_aux_data. An attacker could potentially exploit this by repeatedly triggering the flaw, which may exhaust system memory and result in a Denial of Service (DoS).

Statement

A low-impact memory leak flaw was found in the Linux kernel's Berkeley Packet Filter (BPF) verifier, affecting the Red Hat Enterprise Linux 10.3 kernel and the Red Hat In-Vehicle OS 2.0 and 2.1 kernel streams. When the bpf_check() function successfully allocates env->insn_aux_data but a subsequent allocation of env->succ fails, the error path jumps directly to the err_free_env label and bypasses the vfree() call that releases insn_aux_data, leaking kernel memory. A local attacker with the ability to load BPF programs could repeatedly trigger this error path to exhaust system memory and cause a denial of service; there is no impact on confidentiality or integrity. Red Hat Enterprise Linux 6, 7, 8, and 9, and the rhel-10.0.z and rhel-10.2.z streams, are not affected because the change that introduced this flaw is not present in those kernels. For the affected streams, the fix is currently deferred because this is a low-severity resource leak on an error-handling path that only manifests when a kernel memory allocation fails; the residual risk is a local denial of service through gradual memory exhaustion. The low Red Hat impact rating reflects this limited practical exploitability and is lower than the Moderate CVSS 3.1 base score of 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H) alone would indicate.

CVSS score applicability

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

CVSS / CWE

CVSS 3.1 · 5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE-772 · Missing Release of Resource after Effective Lifetime