BaseFortify

Publication date: 2025-10-01

Last updated on: 2025-12-10

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: Fix UBSAN shift-out-of-bounds warning If get_num_sdma_queues or get_num_xgmi_sdma_queues is 0, we end up doing a shift operation where the number of bits shifted equals number of bits in the operand. This behaviour is undefined. Set num_sdma_queues or num_xgmi_sdma_queues to ULLONG_MAX, if the count is >= number of bits in the operand. Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1472

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Meta Information

Published

2025-10-01

Last Modified

2025-12-10

Generated

2026-07-06

AI Q&A

2025-10-01

EPSS Evaluated

2026-07-05

NVD

CVE-2021-4460

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	to 5.4.118 (exc)
linux	linux_kernel	From 5.5 (inc) to 5.10.36 (exc)
linux	linux_kernel	From 5.11 (inc) to 5.11.20 (exc)
linux	linux_kernel	From 5.12 (inc) to 5.12.3 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-125	The product reads data past the end, or before the beginning, of the intended buffer.

Attack-Flow Graph

Executive Summary

This vulnerability occurs in the Linux kernel's drm/amdkfd component where a shift operation is performed with a number of bits shifted equal to the number of bits in the operand, which is undefined behavior. Specifically, if get_num_sdma_queues or get_num_xgmi_sdma_queues returns 0, this problematic shift happens. The fix involves setting num_sdma_queues or num_xgmi_sdma_queues to ULLONG_MAX if the count is greater than or equal to the number of bits in the operand to avoid the undefined shift.

Impact Analysis

The vulnerability can cause undefined behavior in the Linux kernel when performing certain shift operations, which may lead to system instability, crashes, or unexpected behavior in the drm/amdkfd component. This could affect systems using AMD kernel drivers related to SDMA queues, potentially impacting system reliability.

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