The TKIP key update callback is called from the RX path, where the driver
mutex is already locked. This results in a circular locking bug.
Avoid this by removing the lock.
Johannes noted that there is a separate bug: The callback still breaks on SDIO
hardware, because SDIO hardware access needs to sleep, but we are not allowed
to sleep in the callback due to mac80211's RCU locking.
Signed-off-by: Michael Buesch <m...@bu3sch.de>
Tested-by: Larry Finger <larry.fin...@lwfinger.net>
Reported-by: ke...@kutfo.hit.bme.hu
Cc: Johannes Berg <johan...@sipsolutions.net>
Cc: stable <sta...@kernel.org>
---
drivers/net/wireless/b43/main.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
--- wireless-testing.orig/drivers/net/wireless/b43/main.c
+++ wireless-testing/drivers/net/wireless/b43/main.c
@@ -856,22 +856,19 @@ static void b43_op_update_tkip_key(struc
if (B43_WARN_ON(!modparam_hwtkip))
return;
- mutex_lock(&wl->mutex);
-
+ /* This is only called from the RX path through mac80211, where
+ * our mutex is already locked. */
+ B43_WARN_ON(!mutex_is_locked(&wl->mutex));
dev = wl->current_dev;
- if (!dev || b43_status(dev) < B43_STAT_INITIALIZED)
- goto out_unlock;
+ B43_WARN_ON(!dev || b43_status(dev) < B43_STAT_INITIALIZED);
keymac_write(dev, index, NULL); /* First zero out mac to avoid race */
rx_tkip_phase1_write(dev, index, iv32, phase1key);
/* only pairwise TKIP keys are supported right now */
if (WARN_ON(!sta))
- goto out_unlock;
+ return;
keymac_write(dev, index, sta->addr);
-
-out_unlock:
- mutex_unlock(&wl->mutex);
}
static void do_key_write(struct b43_wldev *dev,
--
Greetings, Michael.
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