Description
In the Linux kernel, the following vulnerability has been resolved:

bpf: Fix stack slot index in nospec checks

check_stack_write_fixed_off() computes the byte slot for a fixed-offset
stack write as -off - 1, and records each written byte in slot_type[] with
(slot - i) % BPF_REG_SIZE.

The Spectre v4 sanitization pre-check uses slot_type[i] instead. For a
4-byte write at fp-8 after the lower half of fp-8 has been zeroed, the
pre-check scans bytes 0..3 and sees STACK_ZERO while the actual write updates
bytes 7..4. That can leave the second half-slot write without nospec_result
even though the bytes being overwritten still require sanitization.

Use the same slot index in the sanitization pre-check that the write path uses
when updating slot_type[].
Published: 2026-08-15
Score: 5.5 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
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Remediation

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History

Mon, 17 Aug 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-1285
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Sat, 15 Aug 2026 19:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-795

Sat, 15 Aug 2026 06:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: bpf: Fix stack slot index in nospec checks check_stack_write_fixed_off() computes the byte slot for a fixed-offset stack write as -off - 1, and records each written byte in slot_type[] with (slot - i) % BPF_REG_SIZE. The Spectre v4 sanitization pre-check uses slot_type[i] instead. For a 4-byte write at fp-8 after the lower half of fp-8 has been zeroed, the pre-check scans bytes 0..3 and sees STACK_ZERO while the actual write updates bytes 7..4. That can leave the second half-slot write without nospec_result even though the bytes being overwritten still require sanitization. Use the same slot index in the sanitization pre-check that the write path uses when updating slot_type[].
Title bpf: Fix stack slot index in nospec checks
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-17T05:14:27.751Z

Reserved: 2026-08-09T03:40:39.928Z

Link: CVE-2026-72428

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-15T06:22:16.637

Modified: 2026-08-17T06:19:10.130

Link: CVE-2026-72428

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-08-15T00:00:00Z

Links: CVE-2026-72428 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-17T15:45:03Z

Weaknesses