CVE-2025-21724: linux kernel Memory Corruption — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: iommufd/iova_bitmap: Fix shift-out-of-bounds in iova_bitmap_offset_to_index() Resolve a UBSAN shift-out-of-bounds issue in iova_bitmap_offset_to_index() where shifting the constant "1" (of type int) by bitmap->mapped.pgshift (an unsigned long value) could result in undefined behavior. The constant "1" defaults to a 32-bit "int", and when "pgshift" exceeds 31 (e.g., pgshift = 63) the shift operation overflows, as the result cannot be represented in a 32-bit type. To resolve this, the constant is updated to "1UL", promoting it to an unsigned long type to match the operand's type.

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CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-787 Out-of-bounds Write

Affected Products

Vendor	Product	Versions
linux	linux_kernel	6.1 — 6.1.129
linux	linux_kernel	6.2 — 6.6.76
linux	linux_kernel	6.7 — 6.12.13
linux	linux_kernel	6.13 — 6.13.2

References

Advisories & Patches

https://git.kernel.org/stable/c/38ac76fc06bc6826a3e4b12a98efbe98432380a9 https://git.kernel.org/stable/c/44d9c94b7a3f29a3e07c4753603a35e9b28842a3 https://git.kernel.org/stable/c/b1f8453b8ff1ab79a03820ef608256c499769cb6 https://git.kernel.org/stable/c/d5d33f01b86af44b23eea61ee309e4ef22c0cdfe https://git.kernel.org/stable/c/e24c1551059268b37f6f40639883eafb281b8b9c

Other References

https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html https://cert-portal.siemens.com/productcert/html/ssa-082556.html

Frequently Asked Questions

What is CVE-2025-21724? +

In the Linux kernel, the following vulnerability has been resolved: iommufd/iova_bitmap: Fix shift-out-of-bounds in iova_bitmap_offset_to_index() Resolve a UBSAN shift-out-of-bounds issue in iova_bitmap_offset_to_index() where shifting the constant "1" (of type int) by bitmap->mapped.pgshift (an unsigned long value) could result in undefined behavior. The constant "1" defaults to a 32-bit "int", and when "pgshift" exceeds 31 (e.g., pgshift = 63) the shift operation overflows, as the result cannot be represented in a 32-bit type. To resolve this, the constant is updated to "1UL", promoting it to an unsigned long type to match the operand's type. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2025-21724? +

CVE-2025-21724 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-21724? +

CVE-2025-21724 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-21724? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2025-21724