From: Zheng Wang zyytlz.wz@163.com

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 [arend.vanspriel@broadcom.com: keep timer delete as is and cancel work just before free] Signed-off-by: Arend van Spriel arend.vanspriel@broadcom.com --- drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c index 133c5ea6429c..52df03243c9f 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c @@ -1179,8 +1179,7 @@ s32 brcmf_notify_escan_complete(struct brcmf_cfg80211_info *cfg, scan_request = cfg->scan_request; cfg->scan_request = NULL;

- if (timer_pending(&cfg->escan_timeout)) - del_timer_sync(&cfg->escan_timeout); + timer_delete_sync(&cfg->escan_timeout);

if (fw_abort) { /* Do a scan abort to stop the driver's scan engine */ @@ -8435,6 +8434,7 @@ void brcmf_cfg80211_detach(struct brcmf_cfg80211_info *cfg) brcmf_btcoex_detach(cfg); wiphy_unregister(cfg->wiphy); wl_deinit_priv(cfg); + cancel_work_sync(&cfg->escan_timeout_work); brcmf_free_wiphy(cfg->wiphy); kfree(cfg); }

base-commit: 3aca362a4c1411ec11ff04f81b6cdf2359fee962