From cd87a2d3a33d75a646f1aa1aa2ee5bf712d6f963 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Fri, 24 Sep 2010 11:20:47 +0200
Subject: [PATCH 1/2] mac80211: fix use-after-free
commit 8c0c709eea5cbab97fb464cd68b06f24acc58ee1
Author: Johannes Berg <johannes@sipsolutions.net>
Date: Wed Nov 25 17:46:15 2009 +0100
mac80211: move cmntr flag out of rx flags
moved the CMTR flag into the skb's status, and
in doing so introduced a use-after-free -- when
the skb has been handed to cooked monitors the
status setting will touch now invalid memory.
Additionally, moving it there has effectively
discarded the optimisation -- since the bit is
only ever set on freed SKBs, and those were a
copy, it could never be checked.
For the current release, fixing this properly
is a bit too involved, so let's just remove the
problematic code and leave userspace with one
copy of each frame for each virtual interface.
Cc: stable@kernel.org [2.6.33+]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---
net/mac80211/rx.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index fa0f37e4afe49..28624282c5f36 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2199,9 +2199,6 @@ static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
struct net_device *prev_dev = NULL;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
- if (status->flag & RX_FLAG_INTERNAL_CMTR)
- goto out_free_skb;
-
if (skb_headroom(skb) < sizeof(*rthdr) &&
pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
goto out_free_skb;
@@ -2260,7 +2257,6 @@ static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
} else
goto out_free_skb;
- status->flag |= RX_FLAG_INTERNAL_CMTR;
return;
out_free_skb:
From e7ee762cf074b0fd8eec483d0cef8fdbf0d04b81 Mon Sep 17 00:00:00 2001
From: Florian Mickler <florian@mickler.org>
Date: Fri, 24 Sep 2010 18:22:01 +0200
Subject: [PATCH 2/2] iwl3945: queue the right work if the scan needs to be
aborted
iwl3945's scan_completed calls into the mac80211 stack which triggers a
warn on if there is no scan outstanding.
This can be avoided by not calling scan_completed but abort_scan in
iwl3945_request_scan in the done: branch of the function which is used
as an error out.
The done: branch seems to be an error-out branch, as, for example, if
iwl_is_ready(priv) returns false the done: branch is executed.
NOTE:
I'm not familiar with the driver at all.
I just quickly scanned as a reaction to
https://bugzilla.kernel.org/show_bug.cgi?id=17722
the users of scan_completed in the iwl3945 driver and noted the odd
discrepancy between the comment above this instance and the comment in
mac80211 scan_completed function.
Signed-off-by: Florian Mickler <florian@mickler.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---
drivers/net/wireless/iwlwifi/iwl-agn-lib.c | 2 +-
drivers/net/wireless/iwlwifi/iwl3945-base.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-lib.c b/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
index 9dd9e64c2b0b1..8fd00a6e51201 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
@@ -1411,7 +1411,7 @@ void iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
clear_bit(STATUS_SCAN_HW, &priv->status);
clear_bit(STATUS_SCANNING, &priv->status);
/* inform mac80211 scan aborted */
- queue_work(priv->workqueue, &priv->scan_completed);
+ queue_work(priv->workqueue, &priv->abort_scan);
}
int iwlagn_manage_ibss_station(struct iwl_priv *priv,
diff --git a/drivers/net/wireless/iwlwifi/iwl3945-base.c b/drivers/net/wireless/iwlwifi/iwl3945-base.c
index 59a308b02f95f..d31661c1ce778 100644
--- a/drivers/net/wireless/iwlwifi/iwl3945-base.c
+++ b/drivers/net/wireless/iwlwifi/iwl3945-base.c
@@ -3018,7 +3018,7 @@ void iwl3945_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
clear_bit(STATUS_SCANNING, &priv->status);
/* inform mac80211 scan aborted */
- queue_work(priv->workqueue, &priv->scan_completed);
+ queue_work(priv->workqueue, &priv->abort_scan);
}
static void iwl3945_bg_restart(struct work_struct *data)