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.

Fixes: e756af5b30b0 ("brcmfmac: add e-scan support.") Signed-off-by: Zheng Wang zyytlz.wz@163.com Cc: stable@vger.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); + cancel_work_sync(&cfg->escan_timeout_work); brcmf_pno_detach(cfg); brcmf_btcoex_detach(cfg); wiphy_unregister(cfg->wiphy);