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authorJohannes Berg <johannes.berg@intel.com>2012-11-29 01:25:20 +0100
committerJohannes Berg <johannes.berg@intel.com>2012-11-30 13:42:20 +0100
commit9caf03640279e64d0ba36539b42daa1b43a49486 (patch)
treecb094a4a577f61421d1b402e16f0e68f151d5726 /drivers/net/wireless/libertas
parentb9a9ada14aab17f08c1d9735601f1097cdcfc6de (diff)
downloadlinux-next-9caf03640279e64d0ba36539b42daa1b43a49486.tar.gz
cfg80211: fix BSS struct IE access races
When a BSS struct is updated, the IEs are currently overwritten or freed. This can lead to races if some other CPU is accessing the BSS struct and using the IEs concurrently. Fix this by always allocating the IEs in a new struct that holds the data and length and protecting access to this new struct with RCU. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'drivers/net/wireless/libertas')
-rw-r--r--drivers/net/wireless/libertas/cfg.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/net/wireless/libertas/cfg.c b/drivers/net/wireless/libertas/cfg.c
index ec36868f6fc5..ec6d5d6b452e 100644
--- a/drivers/net/wireless/libertas/cfg.c
+++ b/drivers/net/wireless/libertas/cfg.c
@@ -298,6 +298,7 @@ static int lbs_add_common_rates_tlv(u8 *tlv, struct cfg80211_bss *bss)
const u8 *rates_eid, *ext_rates_eid;
int n = 0;
+ rcu_read_lock();
rates_eid = ieee80211_bss_get_ie(bss, WLAN_EID_SUPP_RATES);
ext_rates_eid = ieee80211_bss_get_ie(bss, WLAN_EID_EXT_SUPP_RATES);
@@ -325,6 +326,7 @@ static int lbs_add_common_rates_tlv(u8 *tlv, struct cfg80211_bss *bss)
*tlv++ = 0x96;
n = 4;
}
+ rcu_read_unlock();
rate_tlv->header.len = cpu_to_le16(n);
return sizeof(rate_tlv->header) + n;
@@ -1140,11 +1142,13 @@ static int lbs_associate(struct lbs_private *priv,
cmd->capability = cpu_to_le16(bss->capability);
/* add SSID TLV */
+ rcu_read_lock();
ssid_eid = ieee80211_bss_get_ie(bss, WLAN_EID_SSID);
if (ssid_eid)
pos += lbs_add_ssid_tlv(pos, ssid_eid + 2, ssid_eid[1]);
else
lbs_deb_assoc("no SSID\n");
+ rcu_read_unlock();
/* add DS param TLV */
if (bss->channel)
@@ -1782,7 +1786,7 @@ static int lbs_ibss_join_existing(struct lbs_private *priv,
struct cfg80211_ibss_params *params,
struct cfg80211_bss *bss)
{
- const u8 *rates_eid = ieee80211_bss_get_ie(bss, WLAN_EID_SUPP_RATES);
+ const u8 *rates_eid;
struct cmd_ds_802_11_ad_hoc_join cmd;
u8 preamble = RADIO_PREAMBLE_SHORT;
int ret = 0;
@@ -1841,6 +1845,8 @@ static int lbs_ibss_join_existing(struct lbs_private *priv,
/* set rates to the intersection of our rates and the rates in the
bss */
+ rcu_read_lock();
+ rates_eid = ieee80211_bss_get_ie(bss, WLAN_EID_SUPP_RATES);
if (!rates_eid) {
lbs_add_rates(cmd.bss.rates);
} else {
@@ -1860,6 +1866,7 @@ static int lbs_ibss_join_existing(struct lbs_private *priv,
}
}
}
+ rcu_read_unlock();
/* Only v8 and below support setting this */
if (MRVL_FW_MAJOR_REV(priv->fwrelease) <= 8) {