CVE-2025-39891: wifi: mwifiex: Initialize the chan_stats array to zero

Severity: high (CVSS 7.1 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: 2025-10-01 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: wifi: mwifiex: Initialize the chan_stats array to zero The adapter->chan_stats[] array is initialized in mwifiex_init_channel_scan_gap() with vmalloc(), which doesn't zero out memory. The array is filled in mwifiex_update_chan_statistics() and then the user can query the data in mwifiex_cfg80211_dump_survey(). There are two potential issues here. What if the user calls mwifiex_cfg80211_dump_survey() before the data has been filled in. Also the mwifiex_update_chan_statistics() function doesn't necessarily initialize the whole array. Since the array was not initialized at the start that could result in an information leak. Also this array is pretty small. It's a maximum of 900 bytes so it's more appropriate to use kcalloc() instead vmalloc().

Affected products

Debian Linux: 11.0
Linux kernel: from 3.19 before 5.4.299; from 5.5 before 5.10.243; from 5.11 before 5.15.192; from 5.16 before 6.1.151; from 6.2 before 6.6.105; from 6.7 before 6.12.46 — fixed in 5.10.243, 5.15.192, 5.4.299, 6.1.151, 6.12.46, 6.16.6

How to fix

Upgrade to a fixed version: Linux kernel 5.10.243, 5.15.192, 5.4.299, 6.1.151. Check the vendor advisory for mitigations.

References

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