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.

[arend.vanspriel@broadcom.com: keep timer delete as is and cancel work just before free]

kernel.org https://git.kernel.org/stable/c/0a7591e14a8da794d0b93b5d1c6254ccb23adacb [No types assigned]

kernel.org https://git.kernel.org/stable/c/0b812f706fd7090be74812101114a0e165b36744 [No types assigned]

kernel.org https://git.kernel.org/stable/c/0f7352557a35ab7888bc7831411ec8a3cbe20d78 [No types assigned]

kernel.org https://git.kernel.org/stable/c/190794848e2b9d15de92d502b6ac652806904f5a [No types assigned]

kernel.org https://git.kernel.org/stable/c/202c503935042272e2f9e1bb549d5f69a8681169 [No types assigned]

kernel.org https://git.kernel.org/stable/c/6678a1e7d896c00030b31491690e8ddc9a90767a [No types assigned]

kernel.org https://git.kernel.org/stable/c/8c36205123dc57349b59b4f1a2301eb278cbc731 [No types assigned]

kernel.org https://git.kernel.org/stable/c/8e3f03f4ef7c36091f46e7349096efb5a2cdb3a1 [No types assigned]

kernel.org https://git.kernel.org/stable/c/bacb8c3ab86dcd760c15903fcee58169bc3026aa [No types assigned]