---
id: "CVE-2026-98545"
kind: "vulnerability"
aliases: ["CVE-2026-98545"]
title: "Linux kernel: ATA passthru sense handling reads and writes past buffer"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["infrastructure", "kernel", "libata", "linux", "self-hosted"]
not_affected_if: ["no-ata-passthrough", "no-atapi-devices"]
published_at: "2026-10-18T16:17:06+00:00"
first_seen_at: "2026-10-23T21:57:15+00:00"
updated_at: "2026-10-25T05:23:38+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98545", "first_seen_at": "2026-10-23T21:57:15+00:00"}]
---

# Linux kernel: ATA passthru sense handling reads and writes past buffer

The Linux kernel's libata SCSI code trusts a length byte from an ATAPI device's REQUEST SENSE reply when building ATA passthrough sense data, so a faulty or malicious device can cause out-of-bounds kernel memory reads and writes. The fix bounds those descriptor writes to the 96-byte sense buffer.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the running kernel version with `uname -r` and compare it to the fixed kernel in the advisory
- Confirm whether ATA passthrough to ATAPI devices is in use (for example, `smartctl` or `sg_raw` against optical or ATAPI devices)
- unknown for an exact vulnerable version range, as the sources do not say

## Fix

- Update the Linux kernel to a release that includes the libata-scsi fix for CVE-2026-98545 from your distribution or the stable kernel branch
- unknown for the exact fixed version, as the sources do not say

## Timeline

- 2026-10-23T21:57:15+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98545

## From the sources

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

ata: libata-scsi: bound the ATA passthru sense descriptor writes

When an ATA PASS-THROUGH command to an ATAPI device fails, the sense
buffer holds the device's REQUEST SENSE reply, and
ata_scsi_set_passthru_sense_fields() trusts its additional length
byte, sb[7], when adding the ATA Status Return descriptor.  A faulty
or malicious device can use that to make the kernel read and write
past the 96-byte buffer in three ways:

- scsi_sense_desc_find() is passed sb[7] + 8 as the buffer length, so
  its clamp against sb[7] does nothing and the walk runs off the end.
- A type-9 descriptor found near the end is filled in unchecked.
- A new descriptor at sb[8 + len] needs len + 22 bytes, not len + 14,
  so len 75..82 writes up to 8 bytes past the end.

Reproduced with KASAN under qemu, with the emulated ATAPI REQUEST SENSE
reply patched:

  BUG: KASAN: slab-out-of-bounds in scsi_sense_desc_find+0x1a5/0x210
  BUG: KASAN: slab-out-of-bounds in ata_scsi_qc_complete+0x1a15/0x1a50

Both are gone with this patch, and a valid descriptor is still filled
in.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_