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

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-08-22 · updated 2026-07-30
Weakness: CWE-125

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.

Affected products

Linux kernel: 6.16

References

https://git.kernel.org/stable/c/417cfa9cc44fbe6bceab786f9a4ee5a210f1288e
https://git.kernel.org/stable/c/53cf488927a0f79968f9c03c4d1e00d2a79731c3

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