What’s Vulnerable › Vulnerabilities

CVE-2025-21800: net/mlx5: HWS, fix definer's HWS_SET32 macro for negative offset

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-02-27 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: HWS, fix definer's HWS_SET32 macro for negative offset When bit offset for HWS_SET32 macro is negative, UBSAN complains about the shift-out-of-bounds: UBSAN: shift-out-of-bounds in drivers/net/ethernet/mellanox/mlx5/core/steering/hws/definer.c:177:2 shift exponent -8 is negative

Affected products

• Linux kernel: from 6.12 before 6.12.13; from 6.13 before 6.13.2 — fixed in 6.12.13, 6.13.2

How to fix

Upgrade to a fixed version: Linux kernel 6.12.13, 6.13.2. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/69c676c0ded472713e6d1b3a456b3c4f52f66f0e
• https://git.kernel.org/stable/c/92cff996624c4757d5bbace3dfa3f1567ba94143
• https://git.kernel.org/stable/c/be482f1d10da781db9445d2753c1e3f1fd82babf

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