This is a note to let you know that I've just added the patch titled
wifi: brcmfmac: Fix use-after-free bug in brcmf_cfg80211_detach
to the 6.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
wifi-brcmfmac-fix-use-after-free-bug-in-brcmf_cfg802.patch
and it can be found in the queue-6.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 888fd35b12af4d4ef1bf111e7318fd3c1313a8e6
Author: Zheng Wang <zyytlz.wz@xxxxxxx>
Date: Sun Jan 7 08:25:04 2024 +0100
wifi: brcmfmac: Fix use-after-free bug in brcmf_cfg80211_detach
[ Upstream commit 0f7352557a35ab7888bc7831411ec8a3cbe20d78 ]
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
[arend.vanspriel@xxxxxxxxxxxx: keep timer delete as is and cancel work just before free]
Signed-off-by: Arend van Spriel <arend.vanspriel@xxxxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxx>
Link: https://msgid.link/20240107072504.392713-1-arend.vanspriel@xxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
index 1a5d7494f5e80..0c9581a3a67f2 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 */
@@ -8440,6 +8439,7 @@ 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);
}
