There is a circular locking dependency when configuring the
hardware ARP filters on association, occurring when flushing the mac80211
workqueue. This is what happens:
[ 92.026800] =======================================================
[ 92.030507] [ INFO: possible circular locking dependency detected ]
[ 92.030507] 2.6.34-04781-g2b2c009 #85
[ 92.030507] -------------------------------------------------------
[ 92.030507] modprobe/5225 is trying to acquire lock:
[ 92.030507] ((wiphy_name(local->hw.wiphy))){+.+.+.}, at: [<ffffffff8105b5c0>] flush_workq
ueue+0x0/0xb0
[ 92.030507]
[ 92.030507] but task is already holding lock:
[ 92.030507] (rtnl_mutex){+.+.+.}, at: [<ffffffff812b9ce2>] rtnl_lock+0x12/0x20
[ 92.030507]
[ 92.030507] which lock already depends on the new lock.
[ 92.030507]
[ 92.030507]
[ 92.030507] the existing dependency chain (in reverse order) is:
[ 92.030507]
[ 92.030507] -> #2 (rtnl_mutex){+.+.+.}:
[ 92.030507] [<ffffffff810761fb>] lock_acquire+0xdb/0x110
[ 92.030507] [<ffffffff81341754>] mutex_lock_nested+0x44/0x300
[ 92.030507] [<ffffffff812b9ce2>] rtnl_lock+0x12/0x20
[ 92.030507] [<ffffffffa022d47c>] ieee80211_assoc_done+0x6c/0xe0 [mac80211]
[ 92.030507] [<ffffffffa022f2ad>] ieee80211_work_work+0x31d/0x1280 [mac80211]
[ 92.030507] -> #1 ((&local->work_work)){+.+.+.}:
[ 92.030507] [<ffffffff810761fb>] lock_acquire+0xdb/0x110
[ 92.030507] [<ffffffff8105a51a>] worker_thread+0x22a/0x370
[ 92.030507] [<ffffffff8105ecc6>] kthread+0x96/0xb0
[ 92.030507] [<ffffffff81003a94>] kernel_thread_helper+0x4/0x10
[ 92.030507]
[ 92.030507] -> #0 ((wiphy_name(local->hw.wiphy))){+.+.+.}:
[ 92.030507] [<ffffffff81075fdc>] __lock_acquire+0x1c0c/0x1d50
[ 92.030507] [<ffffffff810761fb>] lock_acquire+0xdb/0x110
[ 92.030507] [<ffffffff8105b60e>] flush_workqueue+0x4e/0xb0
[ 92.030507] [<ffffffffa023ff7b>] ieee80211_stop_device+0x2b/0xb0 [mac80211]
[ 92.030507] [<ffffffffa0231635>] ieee80211_stop+0x3e5/0x680 [mac80211]
The locking in this case is quite complex. Fix the problem by rewriting the
way the hardware ARP filter list is handled - i.e. make a copy of the address
list to the bss_conf struct, and provide that list to the hardware driver
when needed.
Additionally, this patch ensures that hardware ARP filtering is not enabled
when promiscuous mode is set.
Reported-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Signed-off-by: Juuso Oikarinen <juuso.oikarinen@xxxxxxxxx>
---
v3: - queue reconfig filter work to kernel default wq instead of mac80211 wq
- initialize arp_filter_state to "true" in if_add
include/net/mac80211.h | 34 +++++----
net/mac80211/driver-ops.h | 17 -----
net/mac80211/driver-trace.h | 25 -------
net/mac80211/ieee80211_i.h | 2 +
net/mac80211/iface.c | 8 ++-
net/mac80211/main.c | 166 +++++++++++++++++++++++++++++--------------
net/mac80211/mlme.c | 39 ++++++----
7 files changed, 164 insertions(+), 127 deletions(-)
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index e3c1d47..f409d00 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -19,7 +19,6 @@
#include <linux/wireless.h>
#include <linux/device.h>
#include <linux/ieee80211.h>
-#include <linux/inetdevice.h>
#include <net/cfg80211.h>
/**
@@ -147,6 +146,7 @@ struct ieee80211_low_level_stats {
* enabled/disabled (beaconing modes)
* @BSS_CHANGED_CQM: Connection quality monitor config changed
* @BSS_CHANGED_IBSS: IBSS join status changed
+ * @BSS_CHANGED_ARP_FILTER: Hardware ARP filter address list or state changed.
*/
enum ieee80211_bss_change {
BSS_CHANGED_ASSOC = 1<<0,
@@ -161,10 +161,18 @@ enum ieee80211_bss_change {
BSS_CHANGED_BEACON_ENABLED = 1<<9,
BSS_CHANGED_CQM = 1<<10,
BSS_CHANGED_IBSS = 1<<11,
+ BSS_CHANGED_ARP_FILTER = 1<<12,
/* when adding here, make sure to change ieee80211_reconfig */
};
+/*
+ * The maximum number of IPv4 addresses listed for ARP filtering. If the number
+ * of addresses for an interface increase beyond this value, hardware ARP
+ * filtering will be disabled.
+ */
+#define IEEE80211_BSS_ARP_ADDR_LIST_LEN 4
+
/**
* struct ieee80211_bss_conf - holds the BSS's changing parameters
*
@@ -200,6 +208,14 @@ enum ieee80211_bss_change {
* @cqm_rssi_thold: Connection quality monitor RSSI threshold, a zero value
* implies disabled
* @cqm_rssi_hyst: Connection quality monitor RSSI hysteresis
+ * @arp_addr_list: List of IPv4 addresses for hardware ARP filtering. The
+ * may filter ARP queries targeted for other addresses than listed here.
+ * The driver must allow ARP queries targeted for all address listed here
+ * to pass through. An empty list implies no ARP queries need to pass.
+ * @arp_addr_cnt: Number of addresses currently on the list.
+ * @arp_filter_enabled: Enable ARP filtering - if enabled, the hardware may
+ * filter ARP queries based on the @arp_addr_list, if disabled, the
+ * hardware must not perform any ARP filtering.
*/
struct ieee80211_bss_conf {
const u8 *bssid;
@@ -220,6 +236,9 @@ struct ieee80211_bss_conf {
s32 cqm_rssi_thold;
u32 cqm_rssi_hyst;
enum nl80211_channel_type channel_type;
+ __be32 arp_addr_list[IEEE80211_BSS_ARP_ADDR_LIST_LEN];
+ u8 arp_addr_cnt;
+ bool arp_filter_enabled;
};
/**
@@ -1529,16 +1548,6 @@ enum ieee80211_ampdu_mlme_action {
* of the bss parameters has changed when a call is made. The callback
* can sleep.
*
- * @configure_arp_filter: Configuration function for hardware ARP query filter.
- * This function is called with all the IP addresses configured to the
- * interface as argument - all ARP queries targeted to any of these
- * addresses must pass through. If the hardware filter does not support
- * enought addresses, hardware filtering must be disabled. The ifa_list
- * argument may be NULL, indicating that filtering must be disabled.
- * This function is called upon association complete with current
- * address(es), and while associated whenever the IP address(es) change.
- * The callback can sleep.
- *
* @prepare_multicast: Prepare for multicast filter configuration.
* This callback is optional, and its return value is passed
* to configure_filter(). This callback must be atomic.
@@ -1678,9 +1687,6 @@ struct ieee80211_ops {
struct ieee80211_vif *vif,
struct ieee80211_bss_conf *info,
u32 changed);
- int (*configure_arp_filter)(struct ieee80211_hw *hw,
- struct ieee80211_vif *vif,
- struct in_ifaddr *ifa_list);
u64 (*prepare_multicast)(struct ieee80211_hw *hw,
struct netdev_hw_addr_list *mc_list);
void (*configure_filter)(struct ieee80211_hw *hw,
diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index d1139e4..bbea3bc 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -83,23 +83,6 @@ static inline void drv_bss_info_changed(struct ieee80211_local *local,
trace_drv_bss_info_changed(local, sdata, info, changed);
}
-struct in_ifaddr;
-static inline int drv_configure_arp_filter(struct ieee80211_local *local,
- struct ieee80211_vif *vif,
- struct in_ifaddr *ifa_list)
-{
- int ret = 0;
-
- might_sleep();
-
- if (local->ops->configure_arp_filter)
- ret = local->ops->configure_arp_filter(&local->hw, vif,
- ifa_list);
-
- trace_drv_configure_arp_filter(local, vif_to_sdata(vif), ifa_list, ret);
- return ret;
-}
-
static inline u64 drv_prepare_multicast(struct ieee80211_local *local,
struct netdev_hw_addr_list *mc_list)
{
diff --git a/net/mac80211/driver-trace.h b/net/mac80211/driver-trace.h
index 6b90630..1e293df 100644
--- a/net/mac80211/driver-trace.h
+++ b/net/mac80211/driver-trace.h
@@ -219,31 +219,6 @@ TRACE_EVENT(drv_bss_info_changed,
)
);
-TRACE_EVENT(drv_configure_arp_filter,
- TP_PROTO(struct ieee80211_local *local,
- struct ieee80211_sub_if_data *sdata,
- struct in_ifaddr *ifa_list, int ret),
-
- TP_ARGS(local, sdata, ifa_list, ret),
-
- TP_STRUCT__entry(
- LOCAL_ENTRY
- VIF_ENTRY
- __field(int, ret)
- ),
-
- TP_fast_assign(
- LOCAL_ASSIGN;
- VIF_ASSIGN;
- __entry->ret = ret;
- ),
-
- TP_printk(
- VIF_PR_FMT LOCAL_PR_FMT " ret:%d",
- VIF_PR_ARG, LOCAL_PR_ARG, __entry->ret
- )
-);
-
TRACE_EVENT(drv_prepare_multicast,
TP_PROTO(struct ieee80211_local *local, int mc_count, u64 ret),
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 4d3883e..79e366e 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -517,6 +517,8 @@ struct ieee80211_sub_if_data {
u16 sequence_number;
+ bool arp_filter_state;
+
/*
* AP this belongs to: self in AP mode and
* corresponding AP in VLAN mode, NULL for
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 1afa9ec..4b64d85 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -588,7 +588,12 @@ static void ieee80211_set_multicast_list(struct net_device *dev)
spin_lock_bh(&local->filter_lock);
__hw_addr_sync(&local->mc_list, &dev->mc, dev->addr_len);
spin_unlock_bh(&local->filter_lock);
- ieee80211_queue_work(&local->hw, &local->reconfig_filter);
+
+ /*
+ * This work cannot be queued in the mac80211 workqueue as it requires
+ * rtnl_lock().
+ */
+ schedule_work(&local->reconfig_filter);
}
/*
@@ -959,6 +964,7 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name,
sdata->wdev.wiphy = local->hw.wiphy;
sdata->local = local;
sdata->dev = ndev;
+ sdata->arp_filter_state = true;
for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
skb_queue_head_init(&sdata->fragments[i].skb_list);
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 5706156..b64066c 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -20,6 +20,7 @@
#include <linux/rtnetlink.h>
#include <linux/bitmap.h>
#include <linux/pm_qos_params.h>
+#include <linux/inetdevice.h>
#include <net/net_namespace.h>
#include <net/cfg80211.h>
@@ -84,12 +85,123 @@ void ieee80211_configure_filter(struct ieee80211_local *local)
local->filter_flags = new_flags & ~(1<<31);
}
+#ifdef CONFIG_INET
+static void ieee80211_reconfig_arp_filter(struct ieee80211_local *local)
+{
+ struct ieee80211_sub_if_data *sdata;
+ struct ieee80211_if_managed *ifmgd;
+ struct ieee80211_bss_conf *bss_conf;
+ u32 changed;
+ bool promisc;
+ bool old_state, new_state;
+
+ /* Check ARP filtering state for each interface */
+ rtnl_lock();
+ list_for_each_entry(sdata, &local->interfaces, list) {
+ if (sdata->vif.type != NL80211_IFTYPE_STATION)
+ continue;
+
+ ifmgd = &sdata->u.mgd;
+ mutex_lock(&ifmgd->mtx);
+ if (!ifmgd->associated) {
+ mutex_unlock(&ifmgd->mtx);
+ continue;
+ }
+
+ bss_conf = &sdata->vif.bss_conf;
+
+ old_state = !!(bss_conf->arp_filter_enabled);
+
+ promisc = sdata->flags & IEEE80211_SDATA_PROMISC;
+ new_state = !promisc && sdata->arp_filter_state;
+ bss_conf->arp_filter_enabled = new_state;
+
+ if (old_state != new_state) {
+ changed = BSS_CHANGED_ARP_FILTER;
+ ieee80211_bss_info_change_notify(sdata, changed);
+ }
+
+ mutex_unlock(&ifmgd->mtx);
+ }
+ rtnl_unlock();
+}
+
+static int ieee80211_ifa_changed(struct notifier_block *nb,
+ unsigned long data, void *arg)
+{
+ struct in_ifaddr *ifa = arg;
+ struct ieee80211_local *local =
+ container_of(nb, struct ieee80211_local,
+ ifa_notifier);
+ struct net_device *ndev = ifa->ifa_dev->dev;
+ struct wireless_dev *wdev = ndev->ieee80211_ptr;
+ struct in_device *idev;
+ struct ieee80211_sub_if_data *sdata;
+ struct ieee80211_bss_conf *bss_conf;
+ struct ieee80211_if_managed *ifmgd;
+ int c = 0;
+
+ /* Make sure it's our interface that got changed */
+ if (!wdev)
+ return NOTIFY_DONE;
+
+ if (wdev->wiphy != local->hw.wiphy)
+ return NOTIFY_DONE;
+
+ sdata = IEEE80211_DEV_TO_SUB_IF(ndev);
+ bss_conf = &sdata->vif.bss_conf;
+
+ /* ARP filtering is only supported in managed mode */
+ if (sdata->vif.type != NL80211_IFTYPE_STATION)
+ return NOTIFY_DONE;
+
+ idev = sdata->dev->ip_ptr;
+ if (!idev)
+ return NOTIFY_DONE;
+
+ ifmgd = &sdata->u.mgd;
+ mutex_lock(&ifmgd->mtx);
+
+ /* Copy the addresses to the bss_conf list */
+ ifa = idev->ifa_list;
+ while (c < IEEE80211_BSS_ARP_ADDR_LIST_LEN && ifa) {
+ bss_conf->arp_addr_list[c] = ifa->ifa_address;
+ ifa = ifa->ifa_next;
+ c++;
+ }
+
+ /* If not all addresses fit the list, disable filtering */
+ if (ifa) {
+ sdata->arp_filter_state = false;
+ c = 0;
+ } else {
+ sdata->arp_filter_state = true;
+ }
+ bss_conf->arp_addr_cnt = c;
+
+ /* Configure driver only if associated and not in promiscuous mode */
+ if (ifmgd->associated && !(sdata->flags & IEEE80211_SDATA_PROMISC)) {
+ bss_conf->arp_filter_enabled = sdata->arp_filter_state;
+ ieee80211_bss_info_change_notify(sdata,
+ BSS_CHANGED_ARP_FILTER);
+ }
+
+ mutex_unlock(&ifmgd->mtx);
+
+ return NOTIFY_DONE;
+}
+#endif
+
static void ieee80211_reconfig_filter(struct work_struct *work)
{
struct ieee80211_local *local =
container_of(work, struct ieee80211_local, reconfig_filter);
ieee80211_configure_filter(local);
+
+#ifdef CONFIG_INET
+ ieee80211_reconfig_arp_filter(local);
+#endif
}
int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
@@ -329,60 +441,6 @@ static void ieee80211_recalc_smps_work(struct work_struct *work)
mutex_unlock(&local->iflist_mtx);
}
-#ifdef CONFIG_INET
-int ieee80211_set_arp_filter(struct ieee80211_sub_if_data *sdata)
-{
- struct in_device *idev;
- int ret = 0;
-
- BUG_ON(!sdata);
- ASSERT_RTNL();
-
- idev = sdata->dev->ip_ptr;
- if (!idev)
- return 0;
-
- ret = drv_configure_arp_filter(sdata->local, &sdata->vif,
- idev->ifa_list);
- return ret;
-}
-
-static int ieee80211_ifa_changed(struct notifier_block *nb,
- unsigned long data, void *arg)
-{
- struct in_ifaddr *ifa = arg;
- struct ieee80211_local *local =
- container_of(nb, struct ieee80211_local,
- ifa_notifier);
- struct net_device *ndev = ifa->ifa_dev->dev;
- struct wireless_dev *wdev = ndev->ieee80211_ptr;
- struct ieee80211_sub_if_data *sdata;
- struct ieee80211_if_managed *ifmgd;
-
- /* Make sure it's our interface that got changed */
- if (!wdev)
- return NOTIFY_DONE;
-
- if (wdev->wiphy != local->hw.wiphy)
- return NOTIFY_DONE;
-
- /* We are concerned about IP addresses only when associated */
- sdata = IEEE80211_DEV_TO_SUB_IF(ndev);
-
- /* ARP filtering is only supported in managed mode */
- if (sdata->vif.type != NL80211_IFTYPE_STATION)
- return NOTIFY_DONE;
-
- ifmgd = &sdata->u.mgd;
- mutex_lock(&ifmgd->mtx);
- if (ifmgd->associated)
- ieee80211_set_arp_filter(sdata);
- mutex_unlock(&ifmgd->mtx);
-
- return NOTIFY_DONE;
-}
-#endif
-
struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
const struct ieee80211_ops *ops)
{
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index ac68c41..d328e9a 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -806,11 +806,12 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
{
struct ieee80211_bss *bss = (void *)cbss->priv;
struct ieee80211_local *local = sdata->local;
+ struct ieee80211_bss_conf *bss_conf = &sdata->vif.bss_conf;
bss_info_changed |= BSS_CHANGED_ASSOC;
/* set timing information */
- sdata->vif.bss_conf.beacon_int = cbss->beacon_interval;
- sdata->vif.bss_conf.timestamp = cbss->tsf;
+ bss_conf->beacon_int = cbss->beacon_interval;
+ bss_conf->timestamp = cbss->tsf;
bss_info_changed |= BSS_CHANGED_BEACON_INT;
bss_info_changed |= ieee80211_handle_bss_capability(sdata,
@@ -835,7 +836,7 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
ieee80211_led_assoc(local, 1);
- sdata->vif.bss_conf.assoc = 1;
+ bss_conf->assoc = 1;
/*
* For now just always ask the driver to update the basic rateset
* when we have associated, we aren't checking whether it actually
@@ -848,9 +849,18 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
/* Tell the driver to monitor connection quality (if supported) */
if ((local->hw.flags & IEEE80211_HW_SUPPORTS_CQM_RSSI) &&
- sdata->vif.bss_conf.cqm_rssi_thold)
+ bss_conf->cqm_rssi_thold)
bss_info_changed |= BSS_CHANGED_CQM;
+#ifdef CONFIG_INET
+ /* Enable ARP filtering unless in promisc mode */
+ if (!(sdata->flags & IEEE80211_SDATA_PROMISC) &&
+ bss_conf->arp_filter_enabled != sdata->arp_filter_state) {
+ bss_conf->arp_filter_enabled = sdata->arp_filter_state;
+ bss_info_changed |= BSS_CHANGED_ARP_FILTER;
+ }
+#endif
+
ieee80211_bss_info_change_notify(sdata, bss_info_changed);
mutex_lock(&local->iflist_mtx);
@@ -932,6 +942,13 @@ static void ieee80211_set_disassoc(struct ieee80211_sub_if_data *sdata,
ieee80211_hw_config(local, config_changed);
+ /* Disable ARP filtering */
+ if (sdata->vif.bss_conf.arp_filter_enabled) {
+ sdata->vif.bss_conf.arp_filter_enabled = false;
+ changed |= BSS_CHANGED_ARP_FILTER;
+ }
+
+
/* The BSSID (not really interesting) and HT changed */
changed |= BSS_CHANGED_BSSID | BSS_CHANGED_HT;
ieee80211_bss_info_change_notify(sdata, changed);
@@ -2116,19 +2133,9 @@ static enum work_done_result ieee80211_assoc_done(struct ieee80211_work *wk,
cfg80211_send_assoc_timeout(wk->sdata->dev,
wk->filter_ta);
return WORK_DONE_DESTROY;
-#ifdef CONFIG_INET
- } else {
- mutex_unlock(&wk->sdata->u.mgd.mtx);
-
- /*
- * configure ARP filter IP addresses to the driver,
- * intentionally outside the mgd mutex.
- */
- rtnl_lock();
- ieee80211_set_arp_filter(wk->sdata);
- rtnl_unlock();
-#endif
}
+
+ mutex_unlock(&wk->sdata->u.mgd.mtx);
}
cfg80211_send_rx_assoc(wk->sdata->dev, skb->data, skb->len);
--
1.6.3.3
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