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authorStanislaw Gruszka <sgruszka@redhat.com>2013-07-26 15:29:09 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-08-29 09:47:38 -0700
commit753fb619d10ed87c9ab5b75e83dd464244986f82 (patch)
treeccb1c2fad22b1e5182e5c71ab8a35c70af26972d
parent323d5a7b5762c2fac8d1a5bb6d24d6d4e0efbfb3 (diff)
iwlwifi: dvm: fix calling ieee80211_chswitch_done() with NULL
commit 9186a1fd9ed190739423db84bc344d258ef3e3d7 upstream. If channel switch is pending and we remove interface we can crash like showed below due to passing NULL vif to mac80211: BUG: unable to handle kernel paging request at fffffffffffff8cc IP: [<ffffffff8130924d>] strnlen+0xd/0x40 Call Trace: [<ffffffff8130ad2e>] string.isra.3+0x3e/0xd0 [<ffffffff8130bf99>] vsnprintf+0x219/0x640 [<ffffffff8130c481>] vscnprintf+0x11/0x30 [<ffffffff81061585>] vprintk_emit+0x115/0x4f0 [<ffffffff81657bd5>] printk+0x61/0x63 [<ffffffffa048987f>] ieee80211_chswitch_done+0xaf/0xd0 [mac80211] [<ffffffffa04e7b34>] iwl_chswitch_done+0x34/0x40 [iwldvm] [<ffffffffa04f83c3>] iwlagn_commit_rxon+0x2a3/0xdc0 [iwldvm] [<ffffffffa04ebc50>] ? iwlagn_set_rxon_chain+0x180/0x2c0 [iwldvm] [<ffffffffa04e5e76>] iwl_set_mode+0x36/0x40 [iwldvm] [<ffffffffa04e5f0d>] iwlagn_mac_remove_interface+0x8d/0x1b0 [iwldvm] [<ffffffffa0459b3d>] ieee80211_do_stop+0x29d/0x7f0 [mac80211] This is because we nulify ctx->vif in iwlagn_mac_remove_interface() before calling some other functions that teardown interface. To fix just check ctx->vif on iwl_chswitch_done(). We should not call ieee80211_chswitch_done() as channel switch works were already canceled by mac80211 in ieee80211_do_stop() -> ieee80211_mgd_stop(). Resolve: https://bugzilla.redhat.com/show_bug.cgi?id=979581 Reported-by: Lukasz Jagiello <jagiello.lukasz@gmail.com> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/net/wireless/iwlwifi/dvm/mac80211.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/net/wireless/iwlwifi/dvm/mac80211.c b/drivers/net/wireless/iwlwifi/dvm/mac80211.c
index cab23af0be9e..e04f3da1ccb3 100644
--- a/drivers/net/wireless/iwlwifi/dvm/mac80211.c
+++ b/drivers/net/wireless/iwlwifi/dvm/mac80211.c
@@ -1059,7 +1059,10 @@ void iwl_chswitch_done(struct iwl_priv *priv, bool is_success)
if (test_bit(STATUS_EXIT_PENDING, &priv->status))
return;
- if (test_and_clear_bit(STATUS_CHANNEL_SWITCH_PENDING, &priv->status))
+ if (!test_and_clear_bit(STATUS_CHANNEL_SWITCH_PENDING, &priv->status))
+ return;
+
+ if (ctx->vif)
ieee80211_chswitch_done(ctx->vif, is_success);
}