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>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlegacy/iwl-core.c b/drivers/net/wireless/iwlegacy/iwl-core.c
index d418b647be80..a209a0e76bf0 100644
--- 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);
         /*