---
id: CVE-2026-98640
title: 'HID: amd_sfh: Validate PCI BAR size before mapping'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  HID: amd_sfh: Validate PCI BAR size before mapping

  The amd_sfh driver maps PCI BAR 2 using pcim_iomap_regions() and
  subsequently accesses MMIO registers at offsets up …
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 4f567b9f8141a86c7d878fadf136e5d1408e3e61 <
    92bf2883da0306ab9d1eb794acd1058fc5088ebc
  - >-
    Linux >= 4f567b9f8141a86c7d878fadf136e5d1408e3e61 <
    7b3747d77767f066ccf4a9e8e3a8381643ab5368
  - >-
    Linux >= 4f567b9f8141a86c7d878fadf136e5d1408e3e61 <
    5ff24aa7af0bca0780fe4e6effce902065f2c0a7
  - >-
    Linux >= 4f567b9f8141a86c7d878fadf136e5d1408e3e61 <
    dc687489131559ee52f447592f6d039a5a013061
  - >-
    Linux >= 4f567b9f8141a86c7d878fadf136e5d1408e3e61 <
    5f9e2ecb725adced013fbf5f94b9f185fad2e7d9
  - >-
    Linux >= 4f567b9f8141a86c7d878fadf136e5d1408e3e61 <
    ee25833f037fa22d23ffdbfeebabe3579e8a0346
  - >-
    Linux >= 4f567b9f8141a86c7d878fadf136e5d1408e3e61 <
    65bcc5f89704efe5b9d69d4ea2c1002d90c31382
  - Linux 5.11
published: '2026-10-18'
updated: '2026-10-18'
sourceUpdated: '2026-10-18T15:20:11.777Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-98640'
references:
  - url: 'https://git.kernel.org/stable/c/92bf2883da0306ab9d1eb794acd1058fc5088ebc'
  - url: 'https://git.kernel.org/stable/c/7b3747d77767f066ccf4a9e8e3a8381643ab5368'
  - url: 'https://git.kernel.org/stable/c/5ff24aa7af0bca0780fe4e6effce902065f2c0a7'
  - url: 'https://git.kernel.org/stable/c/dc687489131559ee52f447592f6d039a5a013061'
  - url: 'https://git.kernel.org/stable/c/5f9e2ecb725adced013fbf5f94b9f185fad2e7d9'
  - url: 'https://git.kernel.org/stable/c/ee25833f037fa22d23ffdbfeebabe3579e8a0346'
  - url: 'https://git.kernel.org/stable/c/65bcc5f89704efe5b9d69d4ea2c1002d90c31382'
tags:
  - cve.org
ingestedAt: '2026-10-18T15:45:12.232Z'
---

## Overview

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

HID: amd_sfh: Validate PCI BAR size before mapping

The amd_sfh driver maps PCI BAR 2 using pcim_iomap_regions() and
subsequently accesses MMIO registers at offsets up to 0x10958 (e.g.,
AMD_P2C_MSG3 at 0x1068C). However, the driver never validates that the BAR
size is large enough to cover these accesses. If the driver is bound to a
device with a smaller BAR 2, this leads to an out-of-bounds memory access
and a page fault during the probe function.

For example, a page fault can occur when reading from privdata->mmio +
AMD_P2C_MSG3 in mp2_select_ops():

  BUG: unable to handle page fault for address: ffffc9000390368c
  PGD 100000067 P4D 100000067 PUD 1012c1067 PMD 105b64067 PTE 0
  Oops: Oops: 0000 [#1] SMP KASAN NOPTI
  RIP: 0010:readl arch/x86/include/asm/io.h:59 [inline]
  RIP: 0010:mp2_select_ops drivers/hid/amd-sfh-hid/amd_sfh_pcie.c:282
  [inline]
  RIP: 0010:amd_mp2_pci_probe+0x337/0x5f0
  drivers/hid/amd-sfh-hid/amd_sfh_pcie.c:487
  Call Trace:
   <TASK>
   local_pci_probe drivers/pci/pci-driver.c:332 [inline]
   pci_call_probe drivers/pci/pci-driver.c:394 [inline]
   __pci_device_probe drivers/pci/pci-driver.c:455 [inline]
   pci_device_probe+0x431/0xc90 drivers/pci/pci-driver.c:489

Fix this by verifying that the length of BAR 2 is at least 128KB before
attempting to map it. Since the maximum accessed offset is 0x10958, and PCI
BAR sizes are powers of 2, any legitimate hardware will have a BAR size of
at least 128KB.

## Affected

- `Linux >= 4f567b9f8141a86c7d878fadf136e5d1408e3e61 < 92bf2883da0306ab9d1eb794acd1058fc5088ebc`
- `Linux >= 4f567b9f8141a86c7d878fadf136e5d1408e3e61 < 7b3747d77767f066ccf4a9e8e3a8381643ab5368`
- `Linux >= 4f567b9f8141a86c7d878fadf136e5d1408e3e61 < 5ff24aa7af0bca0780fe4e6effce902065f2c0a7`
- `Linux >= 4f567b9f8141a86c7d878fadf136e5d1408e3e61 < dc687489131559ee52f447592f6d039a5a013061`
- `Linux >= 4f567b9f8141a86c7d878fadf136e5d1408e3e61 < 5f9e2ecb725adced013fbf5f94b9f185fad2e7d9`
- `Linux >= 4f567b9f8141a86c7d878fadf136e5d1408e3e61 < ee25833f037fa22d23ffdbfeebabe3579e8a0346`
- `Linux >= 4f567b9f8141a86c7d878fadf136e5d1408e3e61 < 65bcc5f89704efe5b9d69d4ea2c1002d90c31382`
- `Linux 5.11`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.