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CVE Record

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

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().

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This Linux kernel issue can leak small amounts of uninitialized kernel memory through survey data from the mwifiex Wi-Fi driver. Business impact depends on whether affected systems use that driver and expose the queried interface. No provided source shows active exploitation or a CVSS score.

Executive priority

Handle through normal kernel vulnerability management unless mwifiex is widely deployed in sensitive environments. The issue is a kernel information leak, but current evidence lacks severity scoring and exploitation confirmation.

Technical view

mwifiex allocates adapter->chan_stats with vmalloc(), which does not zero memory. mwifiex_cfg80211_dump_survey() can return data before full initialization, and mwifiex_update_chan_statistics() may not fill every array entry. The kernel fix initializes allocation with kcalloc(), preventing stale memory disclosure.

Likely exposure

Exposure is likely limited to Linux systems using the mwifiex wireless driver on affected kernel builds. The source bundle lists Linux kernels beginning at 3.19 and multiple stable branches, but does not provide complete distro-specific affected package mapping beyond Debian LTS references.

Exploitation context

The provided sources describe an information leak reachable through querying mwifiex survey data. They do not show public exploitation, weaponized code, KEV listing, or remote unauthenticated exploitation. Treat exploitation status as unconfirmed.

Researcher notes

Focus validation on chan_stats allocation and survey dump paths in mwifiex. The key defect is uninitialized memory disclosure from partially filled channel statistics. Source evidence supports the fix mechanism, but not exploitability scope beyond local querying semantics.

Mitigation direction

  • Update to a vendor kernel containing the referenced stable fixes.
  • Review Debian LTS advisories if running Debian long-term-support kernels.
  • Check your Linux distribution security tracker for package-specific fixed versions.
  • If patching is delayed, follow vendor guidance for mwifiex driver exposure reduction.

Validation and detection

  • Inventory systems using the mwifiex Wi-Fi driver.
  • Compare running kernel versions against vendor fixed package advisories.
  • Confirm deployed kernels include one referenced stable commit or downstream equivalent.
  • Prioritize laptops, embedded devices, and appliances with Marvell mwifiex Wi-Fi hardware.
Prepared
Confidence
medium
Sources
12

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
1ADP providers
11Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

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ADP provider summaries

CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxbf35443314acb43fa8a3f9f8046e14cbe178762b, bf35443314acb43fa8a3f9f8046e14cbe178762b, bf35443314acb43fa8a3f9f8046e14cbe178762b, bf35443314acb43fa8a3f9f8046e14cbe178762b, bf35443314acb43fa8a3f9f8046e14cbe178762b, bf35443314acb43fa8a3f9f8046e14cbe178762b, bf35443314acb43fa8a3f9f8046e14cbe178762b, bf35443314acb43fa8a3f9f8046e14cbe178762bunaffected
LinuxLinux3.19, 0, 5.4.299, 5.10.243, 5.15.192, 6.1.151, 6.6.105, 6.12.46, 6.16.6, 6.17affected
Weakness

CWE details

No CWE listed

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