Description

In the Linux kernel, the following vulnerability has been resolved: wifi: brcmfmac: Fix use-after-free bug in brcmf_cfg80211_detach This is the candidate patch of CVE-2023-47233 : https://nvd.nist.gov/vuln/detail/CVE-2023-47233 In brcm80211 driver,it starts with the following invoking chain to start init a timeout worker: ->brcmf_usb_probe ->brcmf_usb_probe_cb ->brcmf_attach ->brcmf_bus_started ->brcmf_cfg80211_attach ->wl_init_priv ->brcmf_init_escan ->INIT_WORK(&cfg->escan_timeout_work, brcmf_cfg80211_escan_timeout_worker); If we disconnect the USB by hotplug, it will call brcmf_usb_disconnect to make cleanup. The invoking chain is : brcmf_usb_disconnect ->brcmf_usb_disconnect_cb ->brcmf_detach ->brcmf_cfg80211_detach ->kfree(cfg); While the timeout woker may still be running. This will cause a use-after-free bug on cfg in brcmf_cfg80211_escan_timeout_worker. Fix it by deleting the timer and canceling the worker in brcmf_cfg80211_detach. [[email protected]: keep timer delete as is and cancel work just before free]

Severity MEDIUM

CVSS Score 5.5

CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE CWE-416

Public Exploit ✅ No

Source NVD

Published 2024-05-17

Updated 2026-06-02

Modified 2026-05-12

Fix URL https://git.kernel.org/stable/c/0a7591e14a8da794d0b93b5d1c6254ccb23adacb

Software	From version	Fixed in
debian-linux	—	—
linux-kernel	6.8	6.8.3