CVE-2025-39891

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().

The patch fixes an information leak in the Marvell mwifiex driver by zero-initializing the chan_stats array using kcalloc(). Previously, vmalloc() left memory uninitialized, allowing users to read residual kernel data via mwifiex_cfg80211_dump_survey() before full initialization. Impact is confidentiality only (kernel memory exposure); no integrity or availability risk. For the CVSS the PR:L — requires local privileges to trigger survey requests, and in typical systems, only network admins can access this interface.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.