Subject: CVE-2024-35811: wifi: brcmfmac: Fix use-after-free bug in brcmf_cfg80211_detach

From: Greg Kroah-Hartman <[email-masked]>

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-masked]: keep timer delete as is and cancel work just before free]

The Linux kernel CVE team has assigned CVE-2024-35811 to this issue.

Affected and fixed versions
===========================

	Issue introduced in 3.7 with commit e756af5b30b0 and fixed in 4.19.312 with commit 202c50393504
	Issue introduced in 3.7 with commit e756af5b30b0 and fixed in 5.4.274 with commit 8e3f03f4ef7c
	Issue introduced in 3.7 with commit e756af5b30b0 and fixed in 5.10.215 with commit bacb8c3ab86d
	Issue introduced in 3.7 with commit e756af5b30b0 and fixed in 5.15.154 with commit 8c36205123dc
	Issue introduced in 3.7 with commit e756af5b30b0 and fixed in 6.1.84 with commit 0b812f706fd7
	Issue introduced in 3.7 with commit e756af5b30b0 and fixed in 6.6.24 with commit 190794848e2b
	Issue introduced in 3.7 with commit e756af5b30b0 and fixed in 6.7.12 with commit 6678a1e7d896
	Issue introduced in 3.7 with commit e756af5b30b0 and fixed in 6.8.3 with commit 0a7591e14a8d
	Issue introduced in 3.7 with commit e756af5b30b0 and fixed in 6.9 with commit 0f7352557a35

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2024-35811
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/202c503935042272e2f9e1bb549d5f69a8681169
	https://git.kernel.org/stable/c/8e3f03f4ef7c36091f46e7349096efb5a2cdb3a1
	https://git.kernel.org/stable/c/bacb8c3ab86dcd760c15903fcee58169bc3026aa
	https://git.kernel.org/stable/c/8c36205123dc57349b59b4f1a2301eb278cbc731
	https://git.kernel.org/stable/c/0b812f706fd7090be74812101114a0e165b36744
	https://git.kernel.org/stable/c/190794848e2b9d15de92d502b6ac652806904f5a
	https://git.kernel.org/stable/c/6678a1e7d896c00030b31491690e8ddc9a90767a
	https://git.kernel.org/stable/c/0a7591e14a8da794d0b93b5d1c6254ccb23adacb
	https://git.kernel.org/stable/c/0f7352557a35ab7888bc7831411ec8a3cbe20d78