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wifi: brcmfmac: fix use-after-free when rescheduling brcmf_btcoex_info work

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: wifi: brcmfmac: fix use-after-free when rescheduling brcmf_btcoex_info work The brcmf_btcoex_detach() only shuts down the btcoex timer, if the flag timer_on is false. However, the brcmf_btcoex_timerfunc(), which runs as timer handler, sets timer_on to false. This creates critical race conditions: 1.If brcmf_btcoex_detach() is called while brcmf_btcoex_timerfunc() is executing, it may observe timer_on as false and skip the call to timer_shutdown_sync(). 2.The brcmf_btcoex_timerfunc() may then reschedule the brcmf_btcoex_info worker after the cancel_work_sync() has been executed, resulting in use-after-free bugs. The use-after-free bugs occur in two distinct scenarios, depending on the timing of when the brcmf_btcoex_info struct is freed relative to the execution of its worker thread. Scenario 1: Freed before the worker is scheduled The brcmf_btcoex_info is deallocated before the worker is scheduled. A race condition can occur when schedule_work(&bt_local->work) is called after the target memory has been freed. The sequence of events is detailed below: CPU0 | CPU1 brcmf_btcoex_detach | brcmf_btcoex_timerfunc | bt_local->timer_on = false; if (cfg->btcoex->timer_on) | ... | cancel_work_sync(); | ... | kfree(cfg->btcoex); // FREE | | schedule_work(&bt_local->work); // USE Scenario 2: Freed after the worker is scheduled The brcmf_btcoex_info is freed after the worker has been scheduled but before or during its exec

Announced Source revision 1
Original source ↗

CVE-2025-39863

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2025-39863

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "61730d4dfffc2cc9d3a49fad87633008105c18ba",
        "lessThan": "c75600e69e66a751cc046cd9c407b942f298d852",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "61730d4dfffc2cc9d3a49fad87633008105c18ba",
        "lessThan": "ae58f70bde0433f27ef4b388ab50634736607bf6",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "61730d4dfffc2cc9d3a49fad87633008105c18ba",
        "lessThan": "f1150153c4e5940fe49ab51136343c5b4fe49d63",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "61730d4dfffc2cc9d3a49fad87633008105c18ba",
        "lessThan": "3e789f8475f6c857c88de5c5bf4b24b11a477dd7",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "61730d4dfffc2cc9d3a49fad87633008105c18ba",
        "lessThan": "2f6fbc8e04ca1d1d5c560be694199f847229c625",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "61730d4dfffc2cc9d3a49fad87633008105c18ba",
        "lessThan": "9cb83d4be0b9b697eae93d321e0da999f9cdfcfc",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "drivers/net/wireless/broadcom/brcm80211/brcmfmac/btcoex.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "3.10"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "3.10",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "5.15.210",
        "versionType": "semver",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.167",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.105",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.46",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.16.6",
        "versionType": "semver",
        "lessThanOrEqual": "6.16.*"
      },
      {
        "status": "unaffected",
        "version": "6.17",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "drivers/net/wireless/broadcom/brcm80211/brcmfmac/btcoex.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2025-39863

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#27073 · Revision 1
Added to Heist Feed
Publisher date
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