On November 6, 2023 3:44:53 PM Zheng Hacker hackerzheng666@gmail.com wrote:
Thanks! I didn't test it for I don't have a device. Very appreciated if anyone could help with that.
I would volunteer, but it made me dig deep and not sure if there is a problem to solve here.
brcmf_cfg80211_detach() calls wl_deinit_priv() -> brcmf_abort_scanning() -> brcmf_notify_escan_complete() which does delete the timer.
What am I missing here?
Regards, Arend
Kalle Valo kvalo@kernel.org 于2023年11月6日周一 22:41写道：
Zheng Wang zyytlz.wz@163.com writes:
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
v5:
- replace del_timer_sync with timer_shutdown_sync suggested by
Arend and Takashi 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 | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c index 667462369a32..a8723a61c9e4 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c @@ -8431,6 +8431,8 @@ void brcmf_cfg80211_detach(struct brcmf_cfg80211_info *cfg) if (!cfg) return;
timer_shutdown_sync(&cfg->escan_timeout);cancel_work_sync(&cfg->escan_timeout_work);brcmf_pno_detach(cfg); brcmf_btcoex_detach(cfg); wiphy_unregister(cfg->wiphy);
Has anyone tested this on a real device? As v1 didn't even compile I am very cautious:
https://patchwork.kernel.org/project/linux-wireless/patch/20231104054709.716...
-- https://patchwork.kernel.org/project/linux-wireless/list/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatch...