iwlegacy: fix bugs in change_interface

If change_interface gets invoked during a firmware
restart, it may crash; prevent that from happening
by checking if ctx->vif is assigned.

Additionally, in my initial commit I forgot to set
the vif->p2p variable correctly, so fix that too.

Cc: stable@kernel.org [2.6.38+]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/iwlegacy/iwl-core.c b/drivers/net/wireless/iwlegacy/iwl-core.c
index d418b64..a209a0e 100644 (file)
--- a/drivers/net/wireless/iwlegacy/iwl-core.c
+++ b/drivers/net/wireless/iwlegacy/iwl-core.c
@@ -1805,6 +1805,15 @@ iwl_legacy_mac_change_interface(struct ieee80211_hw *hw,
 
        mutex_lock(&priv->mutex);
 
+       if (!ctx->vif || !iwl_legacy_is_ready_rf(priv)) {
+               /*
+                * Huh? But wait ... this can maybe happen when
+                * we're in the middle of a firmware restart!
+                */
+               err = -EBUSY;
+               goto out;
+       }
+
        interface_modes = ctx->interface_modes | ctx->exclusive_interface_modes;
 
        if (!(interface_modes & BIT(newtype))) {
@@ -1832,6 +1841,7 @@ iwl_legacy_mac_change_interface(struct ieee80211_hw *hw,
        /* success */
        iwl_legacy_teardown_interface(priv, vif, true);
        vif->type = newtype;
+       vif->p2p = newp2p;
        err = iwl_legacy_setup_interface(priv, ctx);
        WARN_ON(err);
        /*