5.4-stable review patch. If anyone has any objections, please let me know.
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From: Zheng Wang zyytlz.wz@163.com
[ 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@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 Signed-off-by: Kalle Valo kvalo@kernel.org Link: https://msgid.link/20240107072504.392713-1-arend.vanspriel@broadcom.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 b7ceea0b3204d..668c8897c1095 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c @@ -710,8 +710,7 @@ 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 */ @@ -7240,6 +7239,7 @@ 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); }