b43: Don't abuse wl->current_dev in the led work

Don't abuse wl->current_dev in the LED work for checking whether we're
going down. Add an explicit variable.
This fixes a crash on rmmod dereferencing the wl->current_dev NULL pointer
in various other places of the driver.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 5 insertions, 5 deletions

diff --git a/drivers/net/wireless/b43/leds.c b/drivers/net/wireless/b43/leds.c
index ac5a322c84b7..fbe31e02688b 100644
--- a/drivers/net/wireless/b43/leds.c
+++ b/drivers/net/wireless/b43/leds.c
@@ -112,10 +112,7 @@ static void b43_led_brightness_set(struct led_classdev *led_dev,
         struct b43_led *led = container_of(led_dev, struct b43_led, led_dev);
         struct b43_wl *wl = led->wl;
 
-        /* The check for current_dev is only needed while unregistering,
-         * so it is sequencial and does not race. But we must not dereference
-         * current_dev here. */
-        if (likely(wl->current_dev)) {
+        if (likely(!wl->leds.stop)) {
                 atomic_set(&led->state, brightness);
                 ieee80211_queue_work(wl->hw, &wl->leds.work);
         }
@@ -314,6 +311,8 @@ void b43_leds_init(struct b43_wldev *dev)
                         break;
                 }
         }
+
+        dev->wl->leds.stop = 0;
 }
 
 void b43_leds_exit(struct b43_wldev *dev)
diff --git a/drivers/net/wireless/b43/leds.h b/drivers/net/wireless/b43/leds.h
index c4a58a0fc1d5..49d3da540c28 100644
--- a/drivers/net/wireless/b43/leds.h
+++ b/drivers/net/wireless/b43/leds.h
@@ -35,6 +35,7 @@ struct b43_leds {
         struct b43_led led_radio;
         struct b43_led led_assoc;
 
+        bool stop;
         struct work_struct work;
 };
 
diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c
index 7fa947ca7c32..a8840ef63770 100644
--- a/drivers/net/wireless/b43/main.c
+++ b/drivers/net/wireless/b43/main.c
@@ -4987,7 +4987,7 @@ static void b43_remove(struct ssb_device *dev)
                  * might have modified it. Restoring is important, so the networking
                  * stack can properly free resources. */
                 wl->hw->queues = wl->mac80211_initially_registered_queues;
-                wl->current_dev = NULL;
+                wl->leds.stop = 1;
                 cancel_work_sync(&wl->leds.work);
                 ieee80211_unregister_hw(wl->hw);
         }