{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2025-39863", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2025-39863", "idYear": 2025, "status": "PUBLISHED", "publishedAt": "2025-09-19T15:26:33.069Z", "updatedAt": "2026-10-15T01:08:30.419Z", "importedAt": "2026-10-24T01:57:34.152Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "wifi: brcmfmac: fix use-after-free when rescheduling brcmf_btcoex_info work", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: brcmfmac: fix use-after-free when rescheduling brcmf_btcoex_info work\n\nThe brcmf_btcoex_detach() only shuts down the btcoex timer, if the\nflag timer_on is false. However, the brcmf_btcoex_timerfunc(), which\nruns as timer handler, sets timer_on to false. This creates critical\nrace conditions:\n\n1.If brcmf_btcoex_detach() is called while brcmf_btcoex_timerfunc()\nis executing, it may observe timer_on as false and skip the call to\ntimer_shutdown_sync().\n\n2.The brcmf_btcoex_timerfunc() may then reschedule the brcmf_btcoex_info\nworker after the cancel_work_sync() has been executed, resulting in\nuse-after-free bugs.\n\nThe use-after-free bugs occur in two distinct scenarios, depending on\nthe timing of when the brcmf_btcoex_info struct is freed relative to\nthe execution of its worker thread.\n\nScenario 1: Freed before the worker is scheduled\n\nThe brcmf_btcoex_info is deallocated before the worker is scheduled.\nA race condition can occur when schedule_work(&bt_local->work) is\ncalled after the target memory has been freed. The sequence of events\nis detailed below:\n\nCPU0 | CPU1\nbrcmf_btcoex_detach | brcmf_btcoex_timerfunc\n | bt_local->timer_on = false;\n if (cfg->btcoex->timer_on) |\n ... |\n cancel_work_sync(); |\n ... |\n kfree(cfg->btcoex); // FREE |\n | schedule_work(&bt_local->work); // USE\n\nScenario 2: Freed after the worker is scheduled\n\nThe brcmf_btcoex_info is freed after the worker has been scheduled\nbut before or during its execution. In this case, statements within\nthe brcmf_btcoex_handler() — such as the container_of macro and\nsubsequent dereferences of the brcmf_btcoex_info object will cause\na use-after-free access. The following timeline illustrates this\nscenario:\n\nCPU0 | CPU1\nbrcmf_btcoex_detach | brcmf_btcoex_timerfunc\n | bt_local->timer_on = false;\n if (cfg->btcoex->timer_on) |\n ... |\n cancel_work_sync(); |\n ... | schedule_work(); // Reschedule\n |\n kfree(cfg->btcoex); // FREE | brcmf_btcoex_handler() // Worker\n /* | btci = container_of(....); // USE\n The kfree() above could | ...\n also occur at any point | btci-> // USE\n during the worker's execution|\n */ |\n\nTo resolve the race conditions, drop the conditional check and call\ntimer_shutdown_sync() directly. It can deactivate the timer reliably,\nregardless of its current state. Once stopped, the timer_on state is\nthen set to false.", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "61730d4dfffc2cc9d3a49fad87633008105c18ba", "status": "affected", "versionType": "git", "lessThan": "c75600e69e66a751cc046cd9c407b942f298d852" }, { "version": "61730d4dfffc2cc9d3a49fad87633008105c18ba", "status": "affected", "versionType": "git", "lessThan": "ae58f70bde0433f27ef4b388ab50634736607bf6" }, { "version": "61730d4dfffc2cc9d3a49fad87633008105c18ba", "status": "affected", "versionType": "git", "lessThan": "f1150153c4e5940fe49ab51136343c5b4fe49d63" }, { "version": "61730d4dfffc2cc9d3a49fad87633008105c18ba", "status": "affected", "versionType": "git", "lessThan": "3e789f8475f6c857c88de5c5bf4b24b11a477dd7" }, { "version": "61730d4dfffc2cc9d3a49fad87633008105c18ba", "status": "affected", "versionType": "git", "lessThan": "2f6fbc8e04ca1d1d5c560be694199f847229c625" }, { "version": "61730d4dfffc2cc9d3a49fad87633008105c18ba", "status": "affected", "versionType": "git", "lessThan": "9cb83d4be0b9b697eae93d321e0da999f9cdfcfc" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "3.10", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "3.10" }, { "version": "5.15.210", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.15.*" }, { "version": "6.1.167", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.105", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.46", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.16.6", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.16.*" }, { "version": "6.17", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }