On November 6, 2023 3:44:53 PM Zheng Hacker <hackerzheng666@xxxxxxxxx> 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@xxxxxxxxxx> 于2023年11月6日周一 22:41写道：Zheng Wang <zyytlz.wz@xxxxxxx> 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@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx --- 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.cindex 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/20231104054709.716585-1-zyytlz.wz@xxxxxxx/ -- https://patchwork.kernel.org/project/linux-wireless/list/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
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