CVE-2025-38657 wifi: rtw89: mcc: prevent shift wrapping in rtw89_core_mlsr_switch()

What is CVE-2025-38657?

CVE-2025-38657 is a high-severity vulnerability in Linux kernel, published on 22 Aug 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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

wifi: rtw89: mcc: prevent shift wrapping in rtw89_core_mlsr_switch()

The "link_id" value comes from the user via debugfs. If it's larger than BITS_PER_LONG then that would result in shift wrapping and potentially an out of bounds access later. In fact, we can limit it to IEEE80211_MLD_MAX_NUM_LINKS (15).

Fortunately, only root can write to debugfs files so the security impact is minimal.

Weakness: CWE-125

Which versions are affected by CVE-2025-38657?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2025-38657?

Apply the vendor's patch.

Is CVE-2025-38657 being exploited?

There is no known exploitation of CVE-2025-38657 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2025-38657, GHSA-pxq5-v3xq-vvp3, UBUNTU-CVE-2025-38657.