staging: wfx: fix race between configure_filter and remove_interface

wfx_remove_interface() and wfx_configure_filter() can be run
concurrently. Therefore, this patch protect access to the list of
interfaces from wfx_configure_filter().

Notice that wfx_configure_filter() now lock "conf_lock" and "scan_lock".
Beside that, wfx_hw_scan_work() also access to the same locks. So we
have to lock them in same order to avoid any deadlock.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200410133239.438347-2-Jerome.Pouiller@silabs.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/wfx/scan.c b/drivers/staging/wfx/scan.c
index 6e1e50048651ed184b0868f7f55b3e329c80ca61..0c7f4eef045ce4cea91b657a9ce00925af71279c 100644 (file)
--- a/drivers/staging/wfx/scan.c
+++ b/drivers/staging/wfx/scan.c
@@ -86,8 +86,8 @@ void wfx_hw_scan_work(struct work_struct *work)
        struct ieee80211_scan_request *hw_req = wvif->scan_req;
        int chan_cur, ret;
 
-       mutex_lock(&wvif->scan_lock);
        mutex_lock(&wvif->wdev->conf_mutex);
+       mutex_lock(&wvif->scan_lock);
        update_probe_tmpl(wvif, &hw_req->req);
        wfx_fwd_probe_req(wvif, true);
        chan_cur = 0;
@@ -96,8 +96,8 @@ void wfx_hw_scan_work(struct work_struct *work)
                if (ret > 0)
                        chan_cur += ret;
        } while (ret > 0 && chan_cur < hw_req->req.n_channels);
-       mutex_unlock(&wvif->wdev->conf_mutex);
        mutex_unlock(&wvif->scan_lock);
+       mutex_unlock(&wvif->wdev->conf_mutex);
        __ieee80211_scan_completed_compat(wvif->wdev->hw, ret < 0);
 }
 

diff --git a/drivers/staging/wfx/sta.c b/drivers/staging/wfx/sta.c
index 4d5dbfc24f52f8d610cd6bf16514ac4502789b9b..380e5319472a06b076a941fb849908d20b5d0d83 100644 (file)
--- a/drivers/staging/wfx/sta.c
+++ b/drivers/staging/wfx/sta.c
@@ -242,6 +242,7 @@ void wfx_configure_filter(struct ieee80211_hw *hw,
 
        *total_flags &= FIF_OTHER_BSS | FIF_FCSFAIL | FIF_PROBE_REQ;
 
+       mutex_lock(&wdev->conf_mutex);
        while ((wvif = wvif_iterate(wdev, wvif)) != NULL) {
                mutex_lock(&wvif->scan_lock);
                wvif->filter_bssid = (*total_flags &
@@ -251,6 +252,7 @@ void wfx_configure_filter(struct ieee80211_hw *hw,
                wfx_update_filtering(wvif);
                mutex_unlock(&wvif->scan_lock);
        }
+       mutex_unlock(&wdev->conf_mutex);
 }
 
 static int wfx_update_pm(struct wfx_vif *wvif)