linux-kernel - Re: [PATCH v4] wifi: brcmfmac: Fix use-after-free bug in brcmf_cfg80211

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <849da27a-621f-9c23-f4db-6c20a1d31672@broadcom.com>
Date:   Mon, 6 Nov 2023 11:14:19 +0100
From:   Arend van Spriel <arend.vanspriel@...adcom.com>
To:     Zheng Wang <zyytlz.wz@....com>, aspriel@...il.com
Cc:     franky.lin@...adcom.com, hante.meuleman@...adcom.com,
        kvalo@...nel.org, johannes.berg@...el.com, marcan@...can.st,
        linus.walleij@...aro.org, jisoo.jang@...sei.ac.kr,
        linuxlovemin@...sei.ac.kr, wataru.gohda@...ress.com,
        linux-wireless@...r.kernel.org,
        brcm80211-dev-list.pdl@...adcom.com,
        SHA-cyfmac-dev-list@...ineon.com, linux-kernel@...r.kernel.org,
        security@...nel.org, stable@...r.kernel.org,
        hackerzheng666@...il.com
Subject: Re: [PATCH v4] wifi: brcmfmac: Fix use-after-free bug in
 brcmf_cfg80211_detach

On 11/6/2023 8:30 AM, Zheng Wang wrote:
> This is the candidate patch of CVE-2023-47233 :
> https://nvd.nist.gov/vuln/detail/CVE-2023-47233

[...]

> Fix it by deleting the timer and canceling the worker in
> brcmf_cfg80211_detach.
> 
> Fixes: e756af5b30b0 ("brcmfmac: add e-scan support.")
Reviewed-by: Arend van Spriel <arend.vanspriel@...adcom.com>
> Signed-off-by: Zheng Wang <zyytlz.wz@....com>
> Cc: stable@...r.kernel.org
> ---
> v4:
> - rename the subject and add CVE number as Ping-Ke Shih suggested
> v3:
> - rename the subject as Johannes suggested
> v2:
> - fix the error of kernel test bot reported
> ---
>   drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> index 667462369a32..646ec8bdf512 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> @@ -8431,6 +8431,9 @@ void brcmf_cfg80211_detach(struct brcmf_cfg80211_info *cfg)
>   	if (!cfg)
>   		return;
>   
> +	if (timer_pending(&cfg->escan_timeout))
> +		del_timer_sync(&cfg->escan_timeout);

del_timer_sync() is kept for legacy. Use timer_delete_sync() instead 
[1]. Also checking timer_pending() before deletion is useless looking at 
the return values from timer_delete_sync():

  * Return:
  * * %0	- The timer was not pending
  * * %1	- The timer was pending and deactivated

[1] 
https://elixir.bootlin.com/linux/latest/source/include/linux/timer.h#L190
> +	cancel_work_sync(&cfg->escan_timeout_work);
>   	brcmf_pno_detach(cfg);
>   	brcmf_btcoex_detach(cfg);
>   	wiphy_unregister(cfg->wiphy);

Download attachment "smime.p7s" of type "application/pkcs7-signature" (4219 bytes)