CVE-2026-72098

Received Received - Intake

Buffer Overflow in Linux Kernel dm-verity FEC

Publication date: 2026-08-15

Last updated on: 2026-08-17

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: dm-verity: fix buffer overflow in FEC calculation There's a buffer overflow in dm-verity-fec: if (neras && *neras <= v->fec->roots) fio->erasures[(*neras)++] = i; This allows *neras to reach roots + 1 (the post-increment pushes it past roots). This value is then passed as no_eras to decode_rs8(). Inside the RS decoder (lib/reed_solomon/decode_rs.c:113-121), the erasure locator polynomial loop writes lambda[j] where j can reach nroots + 1 — one element past the end of lambda[] (which is sized nroots + 1, valid indices 0..nroots). The out-of-bounds write lands on syn[0], corrupting the syndrome buffer.

CVSS Scores

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Meta Information

Published

2026-08-15

Last Modified

2026-08-17

Generated

2026-09-04

AI Q&A

2026-08-15

EPSS Evaluated

2026-09-03

NVD

CVE-2026-72098

EUVD

EUVD-2026-59056

Affected Vendors & Products

Vendor	Product	Version / Range
linux_kernel	dm_verity	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability is a buffer overflow in the Linux kernel's dm-verity feature, specifically in the Forward Error Correction (FEC) calculation. The issue occurs when a value exceeds its allocated buffer size, leading to memory corruption. The overflow happens because a counter is incremented beyond its valid range, causing an out-of-bounds write that corrupts adjacent memory, including critical data structures.

Detection Guidance

This vulnerability is specific to the Linux kernel's dm-verity FEC (Forward Error Correction) feature. Detection requires checking kernel logs for buffer overflow errors or examining dm-verity related crashes. Commands like dmesg | grep dm-verity or journalctl -k | grep dm-verity may reveal issues. Ensure your kernel version is updated to a patched release.

Impact Analysis

This vulnerability could allow an attacker to corrupt memory in the kernel, potentially leading to system crashes, privilege escalation, or arbitrary code execution. If exploited, it may compromise the integrity of the dm-verity protected storage, undermining data integrity checks and allowing tampered data to go undetected.

Compliance Impact

This vulnerability could potentially impact compliance with GDPR or HIPAA by compromising data integrity. A buffer overflow in dm-verity-fec may allow unauthorized modifications to stored data, which could violate integrity requirements under these regulations.

Mitigation Strategies

Update your Linux kernel to the latest stable version that includes the dm-verity FEC buffer overflow fix. Avoid using dm-verity with FEC features until patched. Monitor kernel logs for dm-verity related errors. If dm-verity is not critical, consider disabling it temporarily.

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