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>
diff --git a/drivers/net/wireless/libertas/cfg.c b/drivers/net/wireless/libertas/cfg.c
index ec36868..ec6d5d6 100644
--- a/drivers/net/wireless/libertas/cfg.c
+++ b/drivers/net/wireless/libertas/cfg.c
@@ -298,6 +298,7 @@
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 @@
*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 @@
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 @@
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 @@
/* 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 @@
}
}
}
+ rcu_read_unlock();
/* Only v8 and below support setting this */
if (MRVL_FW_MAJOR_REV(priv->fwrelease) <= 8) {
diff --git a/drivers/net/wireless/mwifiex/sta_ioctl.c b/drivers/net/wireless/mwifiex/sta_ioctl.c
index 24af6ba..5d7b83e 100644
--- a/drivers/net/wireless/mwifiex/sta_ioctl.c
+++ b/drivers/net/wireless/mwifiex/sta_ioctl.c
@@ -158,12 +158,22 @@
struct cfg80211_bss *bss,
struct mwifiex_bssdescriptor *bss_desc)
{
- int ret;
+ int ret, beacon_ie_len;
u8 *beacon_ie;
struct mwifiex_bss_priv *bss_priv = (void *)bss->priv;
+ const struct cfg80211_bss_ies *ies;
- beacon_ie = kmemdup(bss->information_elements, bss->len_beacon_ies,
- GFP_KERNEL);
+ rcu_read_lock();
+ ies = rcu_dereference(bss->ies);
+ if (WARN_ON(!ies)) {
+ /* should never happen */
+ rcu_read_unlock();
+ return -EINVAL;
+ }
+ beacon_ie = kmemdup(ies->data, ies->len, GFP_ATOMIC);
+ beacon_ie_len = ies->len;
+ rcu_read_unlock();
+
if (!beacon_ie) {
dev_err(priv->adapter->dev, " failed to alloc beacon_ie\n");
return -ENOMEM;
@@ -172,7 +182,7 @@
memcpy(bss_desc->mac_address, bss->bssid, ETH_ALEN);
bss_desc->rssi = bss->signal;
bss_desc->beacon_buf = beacon_ie;
- bss_desc->beacon_buf_size = bss->len_beacon_ies;
+ bss_desc->beacon_buf_size = beacon_ie_len;
bss_desc->beacon_period = bss->beacon_interval;
bss_desc->cap_info_bitmap = bss->capability;
bss_desc->bss_band = bss_priv->band;
@@ -198,18 +208,23 @@
static int mwifiex_process_country_ie(struct mwifiex_private *priv,
struct cfg80211_bss *bss)
{
- u8 *country_ie, country_ie_len;
+ const u8 *country_ie;
+ u8 country_ie_len;
struct mwifiex_802_11d_domain_reg *domain_info =
&priv->adapter->domain_reg;
- country_ie = (u8 *)ieee80211_bss_get_ie(bss, WLAN_EID_COUNTRY);
-
- if (!country_ie)
+ rcu_read_lock();
+ country_ie = ieee80211_bss_get_ie(bss, WLAN_EID_COUNTRY);
+ if (!country_ie) {
+ rcu_read_unlock();
return 0;
+ }
country_ie_len = country_ie[1];
- if (country_ie_len < IEEE80211_COUNTRY_IE_MIN_LEN)
+ if (country_ie_len < IEEE80211_COUNTRY_IE_MIN_LEN) {
+ rcu_read_unlock();
return 0;
+ }
domain_info->country_code[0] = country_ie[2];
domain_info->country_code[1] = country_ie[3];
@@ -223,6 +238,8 @@
memcpy((u8 *)domain_info->triplet,
&country_ie[2] + IEEE80211_COUNTRY_STRING_LEN, country_ie_len);
+ rcu_read_unlock();
+
if (mwifiex_send_cmd_async(priv, HostCmd_CMD_802_11D_DOMAIN_INFO,
HostCmd_ACT_GEN_SET, 0, NULL)) {
wiphy_err(priv->adapter->wiphy,
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 731b48f..8e6a6b7 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1206,6 +1206,18 @@
};
/**
+ * struct cfg80211_bss_ie_data - BSS entry IE data
+ * @rcu_head: internal use, for freeing
+ * @len: length of the IEs
+ * @data: IE data
+ */
+struct cfg80211_bss_ies {
+ struct rcu_head rcu_head;
+ int len;
+ u8 data[];
+};
+
+/**
* struct cfg80211_bss - BSS description
*
* This structure describes a BSS (which may also be a mesh network)
@@ -1216,36 +1228,34 @@
* @tsf: timestamp of last received update
* @beacon_interval: the beacon interval as from the frame
* @capability: the capability field in host byte order
- * @information_elements: the information elements (Note that there
+ * @ies: the information elements (Note that there
* is no guarantee that these are well-formed!); this is a pointer to
* either the beacon_ies or proberesp_ies depending on whether Probe
* Response frame has been received
- * @len_information_elements: total length of the information elements
* @beacon_ies: the information elements from the last Beacon frame
- * @len_beacon_ies: total length of the beacon_ies
* @proberesp_ies: the information elements from the last Probe Response frame
- * @len_proberesp_ies: total length of the proberesp_ies
* @signal: signal strength value (type depends on the wiphy's signal_type)
* @free_priv: function pointer to free private data
* @priv: private area for driver use, has at least wiphy->bss_priv_size bytes
*/
struct cfg80211_bss {
+ u64 tsf;
+
struct ieee80211_channel *channel;
- u8 bssid[ETH_ALEN];
- u64 tsf;
- u16 beacon_interval;
- u16 capability;
- u8 *information_elements;
- size_t len_information_elements;
- u8 *beacon_ies;
- size_t len_beacon_ies;
- u8 *proberesp_ies;
- size_t len_proberesp_ies;
+ const struct cfg80211_bss_ies __rcu *ies;
+ const struct cfg80211_bss_ies __rcu *beacon_ies;
+ const struct cfg80211_bss_ies __rcu *proberesp_ies;
+
+ void (*free_priv)(struct cfg80211_bss *bss);
s32 signal;
- void (*free_priv)(struct cfg80211_bss *bss);
+ u16 beacon_interval;
+ u16 capability;
+
+ u8 bssid[ETH_ALEN];
+
u8 priv[0] __attribute__((__aligned__(sizeof(void *))));
};
@@ -1253,6 +1263,9 @@
* ieee80211_bss_get_ie - find IE with given ID
* @bss: the bss to search
* @ie: the IE ID
+ *
+ * Note that the return value is an RCU-protected pointer, so
+ * rcu_read_lock() must be held when calling this function.
* Returns %NULL if not found.
*/
const u8 *ieee80211_bss_get_ie(struct cfg80211_bss *bss, u8 ie);
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 35d8cff..481d503 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1382,19 +1382,26 @@
sdata->u.mgd.flags |= IEEE80211_STA_RESET_SIGNAL_AVE;
if (sdata->vif.p2p) {
- u8 noa[2];
- int ret;
+ const struct cfg80211_bss_ies *ies;
- ret = cfg80211_get_p2p_attr(cbss->information_elements,
- cbss->len_information_elements,
- IEEE80211_P2P_ATTR_ABSENCE_NOTICE,
- noa, sizeof(noa));
- if (ret >= 2) {
- bss_conf->p2p_oppps = noa[1] & 0x80;
- bss_conf->p2p_ctwindow = noa[1] & 0x7f;
- bss_info_changed |= BSS_CHANGED_P2P_PS;
- sdata->u.mgd.p2p_noa_index = noa[0];
+ rcu_read_lock();
+ ies = rcu_dereference(cbss->ies);
+ if (ies) {
+ u8 noa[2];
+ int ret;
+
+ ret = cfg80211_get_p2p_attr(
+ ies->data, ies->len,
+ IEEE80211_P2P_ATTR_ABSENCE_NOTICE,
+ noa, sizeof(noa));
+ if (ret >= 2) {
+ bss_conf->p2p_oppps = noa[1] & 0x80;
+ bss_conf->p2p_ctwindow = noa[1] & 0x7f;
+ bss_info_changed |= BSS_CHANGED_P2P_PS;
+ sdata->u.mgd.p2p_noa_index = noa[0];
+ }
}
+ rcu_read_unlock();
}
/* just to be sure */
@@ -1659,6 +1666,7 @@
} else {
int ssid_len;
+ rcu_read_lock();
ssid = ieee80211_bss_get_ie(ifmgd->associated, WLAN_EID_SSID);
if (WARN_ON_ONCE(ssid == NULL))
ssid_len = 0;
@@ -1668,6 +1676,7 @@
ieee80211_send_probe_req(sdata, dst, ssid + 2, ssid_len, NULL,
0, (u32) -1, true, false,
ifmgd->associated->channel, false);
+ rcu_read_unlock();
}
ifmgd->probe_timeout = jiffies + msecs_to_jiffies(probe_wait_ms);
@@ -1763,6 +1772,7 @@
else
return NULL;
+ rcu_read_lock();
ssid = ieee80211_bss_get_ie(cbss, WLAN_EID_SSID);
if (WARN_ON_ONCE(ssid == NULL))
ssid_len = 0;
@@ -1773,6 +1783,7 @@
(u32) -1, cbss->channel,
ssid + 2, ssid_len,
NULL, 0, true);
+ rcu_read_unlock();
return skb;
}
@@ -2858,9 +2869,12 @@
auth_data->bss->bssid, auth_data->tries,
IEEE80211_AUTH_MAX_TRIES);
+ rcu_read_lock();
ssidie = ieee80211_bss_get_ie(auth_data->bss, WLAN_EID_SSID);
- if (!ssidie)
+ if (!ssidie) {
+ rcu_read_unlock();
return -EINVAL;
+ }
/*
* Direct probe is sent to broadcast address as some APs
* will not answer to direct packet in unassociated state.
@@ -2868,6 +2882,7 @@
ieee80211_send_probe_req(sdata, NULL, ssidie + 2, ssidie[1],
NULL, 0, (u32) -1, true, false,
auth_data->bss->channel, false);
+ rcu_read_unlock();
}
auth_data->timeout = jiffies + IEEE80211_AUTH_TIMEOUT;
@@ -3404,9 +3419,7 @@
if (ifmgd->flags & IEEE80211_STA_DISABLE_HT)
return chains;
- ht_cap_ie = cfg80211_find_ie(WLAN_EID_HT_CAPABILITY,
- cbss->information_elements,
- cbss->len_information_elements);
+ ht_cap_ie = ieee80211_bss_get_ie(cbss, WLAN_EID_HT_CAPABILITY);
if (ht_cap_ie && ht_cap_ie[1] >= sizeof(*ht_cap)) {
ht_cap = (void *)(ht_cap_ie + 2);
chains = ieee80211_mcs_to_chains(&ht_cap->mcs);
@@ -3419,9 +3432,7 @@
if (ifmgd->flags & IEEE80211_STA_DISABLE_VHT)
return chains;
- vht_cap_ie = cfg80211_find_ie(WLAN_EID_VHT_CAPABILITY,
- cbss->information_elements,
- cbss->len_information_elements);
+ vht_cap_ie = ieee80211_bss_get_ie(cbss, WLAN_EID_VHT_CAPABILITY);
if (vht_cap_ie && vht_cap_ie[1] >= sizeof(*vht_cap)) {
u8 nss;
u16 tx_mcs_map;
@@ -3457,13 +3468,13 @@
IEEE80211_STA_DISABLE_80P80MHZ |
IEEE80211_STA_DISABLE_160MHZ);
+ rcu_read_lock();
+
if (!(ifmgd->flags & IEEE80211_STA_DISABLE_HT) &&
sband->ht_cap.ht_supported) {
const u8 *ht_oper_ie;
- ht_oper_ie = cfg80211_find_ie(WLAN_EID_HT_OPERATION,
- cbss->information_elements,
- cbss->len_information_elements);
+ ht_oper_ie = ieee80211_bss_get_ie(cbss, WLAN_EID_HT_OPERATION);
if (ht_oper_ie && ht_oper_ie[1] >= sizeof(*ht_oper))
ht_oper = (void *)(ht_oper_ie + 2);
}
@@ -3472,9 +3483,8 @@
sband->vht_cap.vht_supported) {
const u8 *vht_oper_ie;
- vht_oper_ie = cfg80211_find_ie(WLAN_EID_VHT_OPERATION,
- cbss->information_elements,
- cbss->len_information_elements);
+ vht_oper_ie = ieee80211_bss_get_ie(cbss,
+ WLAN_EID_VHT_OPERATION);
if (vht_oper_ie && vht_oper_ie[1] >= sizeof(*vht_oper))
vht_oper = (void *)(vht_oper_ie + 2);
if (vht_oper && !ht_oper) {
@@ -3494,6 +3504,8 @@
sdata->needed_rx_chains = min(ieee80211_ht_vht_rx_chains(sdata, cbss),
local->rx_chains);
+ rcu_read_unlock();
+
/* will change later if needed */
sdata->smps_mode = IEEE80211_SMPS_OFF;
@@ -3734,14 +3746,21 @@
const u8 *ssidie, *ht_ie;
int i, err;
- ssidie = ieee80211_bss_get_ie(req->bss, WLAN_EID_SSID);
- if (!ssidie)
- return -EINVAL;
-
assoc_data = kzalloc(sizeof(*assoc_data) + req->ie_len, GFP_KERNEL);
if (!assoc_data)
return -ENOMEM;
+ rcu_read_lock();
+ ssidie = ieee80211_bss_get_ie(req->bss, WLAN_EID_SSID);
+ if (!ssidie) {
+ rcu_read_unlock();
+ kfree(assoc_data);
+ return -EINVAL;
+ }
+ memcpy(assoc_data->ssid, ssidie + 2, ssidie[1]);
+ assoc_data->ssid_len = ssidie[1];
+ rcu_read_unlock();
+
mutex_lock(&ifmgd->mtx);
if (ifmgd->associated)
@@ -3836,12 +3855,14 @@
assoc_data->supp_rates = bss->supp_rates;
assoc_data->supp_rates_len = bss->supp_rates_len;
+ rcu_read_lock();
ht_ie = ieee80211_bss_get_ie(req->bss, WLAN_EID_HT_OPERATION);
if (ht_ie && ht_ie[1] >= sizeof(struct ieee80211_ht_operation))
assoc_data->ap_ht_param =
((struct ieee80211_ht_operation *)(ht_ie + 2))->ht_param;
else
ifmgd->flags |= IEEE80211_STA_DISABLE_HT;
+ rcu_read_unlock();
if (bss->wmm_used && bss->uapsd_supported &&
(sdata->local->hw.flags & IEEE80211_HW_SUPPORTS_UAPSD)) {
@@ -3852,9 +3873,6 @@
ifmgd->flags &= ~IEEE80211_STA_UAPSD_ENABLED;
}
- memcpy(assoc_data->ssid, ssidie + 2, ssidie[1]);
- assoc_data->ssid_len = ssidie[1];
-
if (req->prev_bssid)
memcpy(assoc_data->prev_bssid, req->prev_bssid, ETH_ALEN);
diff --git a/net/wireless/core.h b/net/wireless/core.h
index 6183a0d..3563097 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -138,8 +138,6 @@
unsigned long ts;
struct kref ref;
atomic_t hold;
- bool beacon_ies_allocated;
- bool proberesp_ies_allocated;
/* must be last because of priv member */
struct cfg80211_bss pub;
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 4a71977..f45706a 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -4808,6 +4808,7 @@
struct cfg80211_internal_bss *intbss)
{
struct cfg80211_bss *res = &intbss->pub;
+ const struct cfg80211_bss_ies *ies;
void *hdr;
struct nlattr *bss;
@@ -4828,16 +4829,24 @@
if (!bss)
goto nla_put_failure;
if ((!is_zero_ether_addr(res->bssid) &&
- nla_put(msg, NL80211_BSS_BSSID, ETH_ALEN, res->bssid)) ||
- (res->information_elements && res->len_information_elements &&
- nla_put(msg, NL80211_BSS_INFORMATION_ELEMENTS,
- res->len_information_elements,
- res->information_elements)) ||
- (res->beacon_ies && res->len_beacon_ies &&
- res->beacon_ies != res->information_elements &&
- nla_put(msg, NL80211_BSS_BEACON_IES,
- res->len_beacon_ies, res->beacon_ies)))
+ nla_put(msg, NL80211_BSS_BSSID, ETH_ALEN, res->bssid)))
goto nla_put_failure;
+
+ rcu_read_lock();
+ ies = rcu_dereference(res->ies);
+ if (ies && ies->len && nla_put(msg, NL80211_BSS_INFORMATION_ELEMENTS,
+ ies->len, ies->data)) {
+ rcu_read_unlock();
+ goto nla_put_failure;
+ }
+ ies = rcu_dereference(res->beacon_ies);
+ if (ies && ies->len && nla_put(msg, NL80211_BSS_BEACON_IES,
+ ies->len, ies->data)) {
+ rcu_read_unlock();
+ goto nla_put_failure;
+ }
+ rcu_read_unlock();
+
if (res->tsf &&
nla_put_u64(msg, NL80211_BSS_TSF, res->tsf))
goto nla_put_failure;
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index bcc7d7e..b6c7ea6 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -1797,7 +1797,7 @@
*/
void regulatory_hint_11d(struct wiphy *wiphy,
enum ieee80211_band band,
- u8 *country_ie,
+ const u8 *country_ie,
u8 country_ie_len)
{
char alpha2[2];
diff --git a/net/wireless/reg.h b/net/wireless/reg.h
index f023c8a..4c0a32f 100644
--- a/net/wireless/reg.h
+++ b/net/wireless/reg.h
@@ -81,7 +81,7 @@
*/
void regulatory_hint_11d(struct wiphy *wiphy,
enum ieee80211_band band,
- u8 *country_ie,
+ const u8 *country_ie,
u8 country_ie_len);
/**
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 834e0d1..01592d7 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -23,6 +23,7 @@
static void bss_release(struct kref *ref)
{
+ struct cfg80211_bss_ies *ies;
struct cfg80211_internal_bss *bss;
bss = container_of(ref, struct cfg80211_internal_bss, ref);
@@ -33,10 +34,12 @@
if (bss->pub.free_priv)
bss->pub.free_priv(&bss->pub);
- if (bss->beacon_ies_allocated)
- kfree(bss->pub.beacon_ies);
- if (bss->proberesp_ies_allocated)
- kfree(bss->pub.proberesp_ies);
+ ies = (void *)rcu_access_pointer(bss->pub.beacon_ies);
+ if (ies)
+ kfree_rcu(ies, rcu_head);
+ ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies);
+ if (ies)
+ kfree_rcu(ies, rcu_head);
kfree(bss);
}
@@ -288,7 +291,7 @@
}
EXPORT_SYMBOL(cfg80211_find_vendor_ie);
-static int cmp_ies(u8 num, u8 *ies1, size_t len1, u8 *ies2, size_t len2)
+static int cmp_ies(u8 num, const u8 *ies1, int len1, const u8 *ies2, int len2)
{
const u8 *ie1 = cfg80211_find_ie(num, ies1, len1);
const u8 *ie2 = cfg80211_find_ie(num, ies2, len2);
@@ -311,6 +314,7 @@
static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
const u8 *ssid, size_t ssid_len)
{
+ const struct cfg80211_bss_ies *ies;
const u8 *ssidie;
if (bssid && !ether_addr_equal(a->bssid, bssid))
@@ -319,9 +323,10 @@
if (!ssid)
return true;
- ssidie = cfg80211_find_ie(WLAN_EID_SSID,
- a->information_elements,
- a->len_information_elements);
+ ies = rcu_access_pointer(a->ies);
+ if (!ies)
+ return false;
+ ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len);
if (!ssidie)
return false;
if (ssidie[1] != ssid_len)
@@ -331,20 +336,21 @@
static bool is_mesh_bss(struct cfg80211_bss *a)
{
+ const struct cfg80211_bss_ies *ies;
const u8 *ie;
if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability))
return false;
- ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
- a->information_elements,
- a->len_information_elements);
+ ies = rcu_access_pointer(a->ies);
+ if (!ies)
+ return false;
+
+ ie = cfg80211_find_ie(WLAN_EID_MESH_ID, ies->data, ies->len);
if (!ie)
return false;
- ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
- a->information_elements,
- a->len_information_elements);
+ ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, ies->data, ies->len);
if (!ie)
return false;
@@ -355,14 +361,17 @@
const u8 *meshid, size_t meshidlen,
const u8 *meshcfg)
{
+ const struct cfg80211_bss_ies *ies;
const u8 *ie;
if (!WLAN_CAPABILITY_IS_STA_BSS(a->capability))
return false;
- ie = cfg80211_find_ie(WLAN_EID_MESH_ID,
- a->information_elements,
- a->len_information_elements);
+ ies = rcu_access_pointer(a->ies);
+ if (!ies)
+ return false;
+
+ ie = cfg80211_find_ie(WLAN_EID_MESH_ID, ies->data, ies->len);
if (!ie)
return false;
if (ie[1] != meshidlen)
@@ -370,9 +379,7 @@
if (memcmp(ie + 2, meshid, meshidlen))
return false;
- ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG,
- a->information_elements,
- a->len_information_elements);
+ ie = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, ies->data, ies->len);
if (!ie)
return false;
if (ie[1] != sizeof(struct ieee80211_meshconf_ie))
@@ -389,24 +396,28 @@
static int cmp_bss_core(struct cfg80211_bss *a, struct cfg80211_bss *b)
{
+ const struct cfg80211_bss_ies *a_ies, *b_ies;
int r;
if (a->channel != b->channel)
return b->channel->center_freq - a->channel->center_freq;
if (is_mesh_bss(a) && is_mesh_bss(b)) {
+ a_ies = rcu_access_pointer(a->ies);
+ if (!a_ies)
+ return -1;
+ b_ies = rcu_access_pointer(b->ies);
+ if (!b_ies)
+ return 1;
+
r = cmp_ies(WLAN_EID_MESH_ID,
- a->information_elements,
- a->len_information_elements,
- b->information_elements,
- b->len_information_elements);
+ a_ies->data, a_ies->len,
+ b_ies->data, b_ies->len);
if (r)
return r;
return cmp_ies(WLAN_EID_MESH_CONFIG,
- a->information_elements,
- a->len_information_elements,
- b->information_elements,
- b->len_information_elements);
+ a_ies->data, a_ies->len,
+ b_ies->data, b_ies->len);
}
/*
@@ -419,21 +430,28 @@
static int cmp_bss(struct cfg80211_bss *a,
struct cfg80211_bss *b)
{
+ const struct cfg80211_bss_ies *a_ies, *b_ies;
int r;
r = cmp_bss_core(a, b);
if (r)
return r;
+ a_ies = rcu_access_pointer(a->ies);
+ if (!a_ies)
+ return -1;
+ b_ies = rcu_access_pointer(b->ies);
+ if (!b_ies)
+ return 1;
+
return cmp_ies(WLAN_EID_SSID,
- a->information_elements,
- a->len_information_elements,
- b->information_elements,
- b->len_information_elements);
+ a_ies->data, a_ies->len,
+ b_ies->data, b_ies->len);
}
static int cmp_hidden_bss(struct cfg80211_bss *a, struct cfg80211_bss *b)
{
+ const struct cfg80211_bss_ies *a_ies, *b_ies;
const u8 *ie1;
const u8 *ie2;
int i;
@@ -443,12 +461,15 @@
if (r)
return r;
- ie1 = cfg80211_find_ie(WLAN_EID_SSID,
- a->information_elements,
- a->len_information_elements);
- ie2 = cfg80211_find_ie(WLAN_EID_SSID,
- b->information_elements,
- b->len_information_elements);
+ a_ies = rcu_access_pointer(a->ies);
+ if (!a_ies)
+ return -1;
+ b_ies = rcu_access_pointer(b->ies);
+ if (!b_ies)
+ return 1;
+
+ ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len);
+ ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len);
/*
* Key comparator must use same algorithm in any rb-tree
@@ -633,126 +654,84 @@
copy_hidden_ies(struct cfg80211_internal_bss *res,
struct cfg80211_internal_bss *hidden)
{
- if (unlikely(res->pub.beacon_ies))
- return;
- if (WARN_ON(!hidden->pub.beacon_ies))
+ const struct cfg80211_bss_ies *ies;
+
+ if (rcu_access_pointer(res->pub.beacon_ies))
return;
- res->pub.beacon_ies = kmalloc(hidden->pub.len_beacon_ies, GFP_ATOMIC);
- if (unlikely(!res->pub.beacon_ies))
+ ies = rcu_access_pointer(hidden->pub.beacon_ies);
+ if (WARN_ON(!ies))
return;
- res->beacon_ies_allocated = true;
- res->pub.len_beacon_ies = hidden->pub.len_beacon_ies;
- memcpy(res->pub.beacon_ies, hidden->pub.beacon_ies,
- res->pub.len_beacon_ies);
+ ies = kmemdup(ies, sizeof(*ies) + ies->len, GFP_ATOMIC);
+ if (unlikely(!ies))
+ return;
+ rcu_assign_pointer(res->pub.beacon_ies, ies);
}
static struct cfg80211_internal_bss *
cfg80211_bss_update(struct cfg80211_registered_device *dev,
- struct cfg80211_internal_bss *res)
+ struct cfg80211_internal_bss *tmp)
{
struct cfg80211_internal_bss *found = NULL;
- /*
- * The reference to "res" is donated to this function.
- */
-
- if (WARN_ON(!res->pub.channel)) {
- kref_put(&res->ref, bss_release);
+ if (WARN_ON(!tmp->pub.channel))
return NULL;
- }
- res->ts = jiffies;
+ tmp->ts = jiffies;
spin_lock_bh(&dev->bss_lock);
- found = rb_find_bss(dev, res);
+ if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
+ spin_unlock_bh(&dev->bss_lock);
+ return NULL;
+ }
+
+ found = rb_find_bss(dev, tmp);
if (found) {
- found->pub.beacon_interval = res->pub.beacon_interval;
- found->pub.tsf = res->pub.tsf;
- found->pub.signal = res->pub.signal;
- found->pub.capability = res->pub.capability;
- found->ts = res->ts;
+ found->pub.beacon_interval = tmp->pub.beacon_interval;
+ found->pub.tsf = tmp->pub.tsf;
+ found->pub.signal = tmp->pub.signal;
+ found->pub.capability = tmp->pub.capability;
+ found->ts = tmp->ts;
/* Update IEs */
- if (res->pub.proberesp_ies) {
- size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
- size_t ielen = res->pub.len_proberesp_ies;
+ if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
+ const struct cfg80211_bss_ies *old;
- if (found->pub.proberesp_ies &&
- !found->proberesp_ies_allocated &&
- ksize(found) >= used + ielen) {
- memcpy(found->pub.proberesp_ies,
- res->pub.proberesp_ies, ielen);
- found->pub.len_proberesp_ies = ielen;
- } else {
- u8 *ies = found->pub.proberesp_ies;
+ old = rcu_access_pointer(found->pub.proberesp_ies);
- if (found->proberesp_ies_allocated)
- ies = krealloc(ies, ielen, GFP_ATOMIC);
- else
- ies = kmalloc(ielen, GFP_ATOMIC);
-
- if (ies) {
- memcpy(ies, res->pub.proberesp_ies,
- ielen);
- found->proberesp_ies_allocated = true;
- found->pub.proberesp_ies = ies;
- found->pub.len_proberesp_ies = ielen;
- }
- }
-
+ rcu_assign_pointer(found->pub.proberesp_ies,
+ tmp->pub.proberesp_ies);
/* Override possible earlier Beacon frame IEs */
- found->pub.information_elements =
- found->pub.proberesp_ies;
- found->pub.len_information_elements =
- found->pub.len_proberesp_ies;
- }
+ rcu_assign_pointer(found->pub.ies,
+ tmp->pub.proberesp_ies);
+ if (old)
+ kfree_rcu((struct cfg80211_bss_ies *)old,
+ rcu_head);
+ } else if (rcu_access_pointer(tmp->pub.beacon_ies)) {
+ const struct cfg80211_bss_ies *old, *ies;
- if (res->pub.beacon_ies) {
- size_t used = dev->wiphy.bss_priv_size + sizeof(*res);
- size_t ielen = res->pub.len_beacon_ies;
- bool information_elements_is_beacon_ies =
- (found->pub.information_elements ==
- found->pub.beacon_ies);
+ old = rcu_access_pointer(found->pub.beacon_ies);
+ ies = rcu_access_pointer(found->pub.ies);
- if (found->pub.beacon_ies &&
- !found->beacon_ies_allocated &&
- ksize(found) >= used + ielen) {
- memcpy(found->pub.beacon_ies,
- res->pub.beacon_ies, ielen);
- found->pub.len_beacon_ies = ielen;
- } else {
- u8 *ies = found->pub.beacon_ies;
-
- if (found->beacon_ies_allocated)
- ies = krealloc(ies, ielen, GFP_ATOMIC);
- else
- ies = kmalloc(ielen, GFP_ATOMIC);
-
- if (ies) {
- memcpy(ies, res->pub.beacon_ies,
- ielen);
- found->beacon_ies_allocated = true;
- found->pub.beacon_ies = ies;
- found->pub.len_beacon_ies = ielen;
- }
- }
+ rcu_assign_pointer(found->pub.beacon_ies,
+ tmp->pub.beacon_ies);
/* Override IEs if they were from a beacon before */
- if (information_elements_is_beacon_ies) {
- found->pub.information_elements =
- found->pub.beacon_ies;
- found->pub.len_information_elements =
- found->pub.len_beacon_ies;
- }
- }
+ if (old == ies)
+ rcu_assign_pointer(found->pub.ies,
+ tmp->pub.beacon_ies);
- kref_put(&res->ref, bss_release);
+ if (old)
+ kfree_rcu((struct cfg80211_bss_ies *)old,
+ rcu_head);
+ }
} else {
+ struct cfg80211_internal_bss *new;
struct cfg80211_internal_bss *hidden;
+ struct cfg80211_bss_ies *ies;
/* First check if the beacon is a probe response from
* a hidden bss. If so, copy beacon ies (with nullified
@@ -763,14 +742,32 @@
/* TODO: The code is not trying to update existing probe
* response bss entries when beacon ies are
* getting changed. */
- hidden = rb_find_hidden_bss(dev, res);
+ hidden = rb_find_hidden_bss(dev, tmp);
if (hidden)
- copy_hidden_ies(res, hidden);
+ copy_hidden_ies(tmp, hidden);
- /* this "consumes" the reference */
- list_add_tail(&res->list, &dev->bss_list);
- rb_insert_bss(dev, res);
- found = res;
+ /*
+ * create a copy -- the "res" variable that is passed in
+ * is allocated on the stack since it's not needed in the
+ * more common case of an update
+ */
+ new = kzalloc(sizeof(*new) + dev->wiphy.bss_priv_size,
+ GFP_ATOMIC);
+ if (!new) {
+ ies = (void *)rcu_dereference(tmp->pub.beacon_ies);
+ if (ies)
+ kfree_rcu(ies, rcu_head);
+ ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
+ if (ies)
+ kfree_rcu(ies, rcu_head);
+ spin_unlock_bh(&dev->bss_lock);
+ return NULL;
+ }
+ memcpy(new, tmp, sizeof(*new));
+ kref_init(&new->ref);
+ list_add_tail(&new->list, &dev->bss_list);
+ rb_insert_bss(dev, new);
+ found = new;
}
dev->bss_generation++;
@@ -819,14 +816,12 @@
u16 beacon_interval, const u8 *ie, size_t ielen,
s32 signal, gfp_t gfp)
{
- struct cfg80211_internal_bss *res;
- size_t privsz;
+ struct cfg80211_bss_ies *ies;
+ struct cfg80211_internal_bss tmp = {}, *res;
if (WARN_ON(!wiphy))
return NULL;
- privsz = wiphy->bss_priv_size;
-
if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
(signal < 0 || signal > 100)))
return NULL;
@@ -835,36 +830,33 @@
if (!channel)
return NULL;
- res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
- if (!res)
- return NULL;
-
- memcpy(res->pub.bssid, bssid, ETH_ALEN);
- res->pub.channel = channel;
- res->pub.signal = signal;
- res->pub.tsf = tsf;
- res->pub.beacon_interval = beacon_interval;
- res->pub.capability = capability;
+ memcpy(tmp.pub.bssid, bssid, ETH_ALEN);
+ tmp.pub.channel = channel;
+ tmp.pub.signal = signal;
+ tmp.pub.tsf = tsf;
+ tmp.pub.beacon_interval = beacon_interval;
+ tmp.pub.capability = capability;
/*
* Since we do not know here whether the IEs are from a Beacon or Probe
* Response frame, we need to pick one of the options and only use it
* with the driver that does not provide the full Beacon/Probe Response
* frame. Use Beacon frame pointer to avoid indicating that this should
- * override the information_elements pointer should we have received an
- * earlier indication of Probe Response data.
+ * override the iies pointer should we have received an earlier
+ * indication of Probe Response data.
*
* The initial buffer for the IEs is allocated with the BSS entry and
* is located after the private area.
*/
- res->pub.beacon_ies = (u8 *)res + sizeof(*res) + privsz;
- memcpy(res->pub.beacon_ies, ie, ielen);
- res->pub.len_beacon_ies = ielen;
- res->pub.information_elements = res->pub.beacon_ies;
- res->pub.len_information_elements = res->pub.len_beacon_ies;
+ ies = kmalloc(sizeof(*ies) + ielen, gfp);
+ if (!ies)
+ return NULL;
+ ies->len = ielen;
+ memcpy(ies->data, ie, ielen);
- kref_init(&res->ref);
+ rcu_assign_pointer(tmp.pub.beacon_ies, ies);
+ rcu_assign_pointer(tmp.pub.ies, ies);
- res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
+ res = cfg80211_bss_update(wiphy_to_dev(wiphy), &tmp);
if (!res)
return NULL;
@@ -883,10 +875,10 @@
struct ieee80211_mgmt *mgmt, size_t len,
s32 signal, gfp_t gfp)
{
- struct cfg80211_internal_bss *res;
+ struct cfg80211_internal_bss tmp = {}, *res;
+ struct cfg80211_bss_ies *ies;
size_t ielen = len - offsetof(struct ieee80211_mgmt,
u.probe_resp.variable);
- size_t privsz;
BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) !=
offsetof(struct ieee80211_mgmt, u.beacon.variable));
@@ -906,45 +898,31 @@
if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
return NULL;
- privsz = wiphy->bss_priv_size;
-
channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable,
ielen, channel);
if (!channel)
return NULL;
- res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
- if (!res)
+ ies = kmalloc(sizeof(*ies) + ielen, gfp);
+ if (!ies)
return NULL;
+ ies->len = ielen;
+ memcpy(ies->data, mgmt->u.probe_resp.variable, ielen);
- memcpy(res->pub.bssid, mgmt->bssid, ETH_ALEN);
- res->pub.channel = channel;
- res->pub.signal = signal;
- res->pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
- res->pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
- res->pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
- /*
- * The initial buffer for the IEs is allocated with the BSS entry and
- * is located after the private area.
- */
- if (ieee80211_is_probe_resp(mgmt->frame_control)) {
- res->pub.proberesp_ies = (u8 *) res + sizeof(*res) + privsz;
- memcpy(res->pub.proberesp_ies, mgmt->u.probe_resp.variable,
- ielen);
- res->pub.len_proberesp_ies = ielen;
- res->pub.information_elements = res->pub.proberesp_ies;
- res->pub.len_information_elements = res->pub.len_proberesp_ies;
- } else {
- res->pub.beacon_ies = (u8 *) res + sizeof(*res) + privsz;
- memcpy(res->pub.beacon_ies, mgmt->u.beacon.variable, ielen);
- res->pub.len_beacon_ies = ielen;
- res->pub.information_elements = res->pub.beacon_ies;
- res->pub.len_information_elements = res->pub.len_beacon_ies;
- }
+ if (ieee80211_is_probe_resp(mgmt->frame_control))
+ rcu_assign_pointer(tmp.pub.proberesp_ies, ies);
+ else
+ rcu_assign_pointer(tmp.pub.beacon_ies, ies);
+ rcu_assign_pointer(tmp.pub.ies, ies);
+
+ memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN);
+ tmp.pub.channel = channel;
+ tmp.pub.signal = signal;
+ tmp.pub.tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp);
+ tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int);
+ tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info);
- kref_init(&res->ref);
-
- res = cfg80211_bss_update(wiphy_to_dev(wiphy), res);
+ res = cfg80211_bss_update(wiphy_to_dev(wiphy), &tmp);
if (!res)
return NULL;
@@ -1136,22 +1114,21 @@
EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan);
static void ieee80211_scan_add_ies(struct iw_request_info *info,
- struct cfg80211_bss *bss,
+ const struct cfg80211_bss_ies *ies,
char **current_ev, char *end_buf)
{
- u8 *pos, *end, *next;
+ const u8 *pos, *end, *next;
struct iw_event iwe;
- if (!bss->information_elements ||
- !bss->len_information_elements)
+ if (!ies)
return;
/*
* If needed, fragment the IEs buffer (at IE boundaries) into short
* enough fragments to fit into IW_GENERIC_IE_MAX octet messages.
*/
- pos = bss->information_elements;
- end = pos + bss->len_information_elements;
+ pos = ies->data;
+ end = pos + ies->len;
while (end - pos > IW_GENERIC_IE_MAX) {
next = pos + 2 + pos[1];
@@ -1162,7 +1139,8 @@
iwe.cmd = IWEVGENIE;
iwe.u.data.length = next - pos;
*current_ev = iwe_stream_add_point(info, *current_ev,
- end_buf, &iwe, pos);
+ end_buf, &iwe,
+ (void *)pos);
pos = next;
}
@@ -1172,7 +1150,8 @@
iwe.cmd = IWEVGENIE;
iwe.u.data.length = end - pos;
*current_ev = iwe_stream_add_point(info, *current_ev,
- end_buf, &iwe, pos);
+ end_buf, &iwe,
+ (void *)pos);
}
}
@@ -1191,10 +1170,11 @@
struct cfg80211_internal_bss *bss, char *current_ev,
char *end_buf)
{
+ const struct cfg80211_bss_ies *ies;
struct iw_event iwe;
+ const u8 *ie;
u8 *buf, *cfg, *p;
- u8 *ie = bss->pub.information_elements;
- int rem = bss->pub.len_information_elements, i, sig;
+ int rem, i, sig;
bool ismesh = false;
memset(&iwe, 0, sizeof(iwe));
@@ -1259,7 +1239,17 @@
current_ev = iwe_stream_add_point(info, current_ev, end_buf,
&iwe, "");
- while (rem >= 2) {
+ rcu_read_lock();
+ ies = rcu_dereference(bss->pub.ies);
+ if (ies) {
+ rem = ies->len;
+ ie = ies->data;
+ } else {
+ rem = 0;
+ ie = NULL;
+ }
+
+ while (ies && rem >= 2) {
/* invalid data */
if (ie[1] > rem - 2)
break;
@@ -1271,7 +1261,7 @@
iwe.u.data.length = ie[1];
iwe.u.data.flags = 1;
current_ev = iwe_stream_add_point(info, current_ev, end_buf,
- &iwe, ie + 2);
+ &iwe, (u8 *)ie + 2);
break;
case WLAN_EID_MESH_ID:
memset(&iwe, 0, sizeof(iwe));
@@ -1279,7 +1269,7 @@
iwe.u.data.length = ie[1];
iwe.u.data.flags = 1;
current_ev = iwe_stream_add_point(info, current_ev, end_buf,
- &iwe, ie + 2);
+ &iwe, (u8 *)ie + 2);
break;
case WLAN_EID_MESH_CONFIG:
ismesh = true;
@@ -1288,7 +1278,7 @@
buf = kmalloc(50, GFP_ATOMIC);
if (!buf)
break;
- cfg = ie + 2;
+ cfg = (u8 *)ie + 2;
memset(&iwe, 0, sizeof(iwe));
iwe.cmd = IWEVCUSTOM;
sprintf(buf, "Mesh Network Path Selection Protocol ID: "
@@ -1386,7 +1376,8 @@
kfree(buf);
}
- ieee80211_scan_add_ies(info, &bss->pub, ¤t_ev, end_buf);
+ ieee80211_scan_add_ies(info, ies, ¤t_ev, end_buf);
+ rcu_read_unlock();
return current_ev;
}
diff --git a/net/wireless/sme.c b/net/wireless/sme.c
index c749002..f2431e4 100644
--- a/net/wireless/sme.c
+++ b/net/wireless/sme.c
@@ -417,7 +417,7 @@
struct cfg80211_bss *bss)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
- u8 *country_ie;
+ const u8 *country_ie;
#ifdef CONFIG_CFG80211_WEXT
union iwreq_data wrqu;
#endif
@@ -501,7 +501,15 @@
wdev->sme_state = CFG80211_SME_CONNECTED;
cfg80211_upload_connect_keys(wdev);
- country_ie = (u8 *) ieee80211_bss_get_ie(bss, WLAN_EID_COUNTRY);
+ rcu_read_lock();
+ country_ie = ieee80211_bss_get_ie(bss, WLAN_EID_COUNTRY);
+ if (!country_ie) {
+ rcu_read_unlock();
+ return;
+ }
+
+ country_ie = kmemdup(country_ie, 2 + country_ie[1], GFP_ATOMIC);
+ rcu_read_unlock();
if (!country_ie)
return;
@@ -515,6 +523,7 @@
bss->channel->band,
country_ie + 2,
country_ie[1]);
+ kfree(country_ie);
}
void cfg80211_connect_result(struct net_device *dev, const u8 *bssid,
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 3cce6e4..16d76a8 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -688,10 +688,13 @@
const u8 *ieee80211_bss_get_ie(struct cfg80211_bss *bss, u8 ie)
{
- if (bss->information_elements == NULL)
+ const struct cfg80211_bss_ies *ies;
+
+ ies = rcu_dereference(bss->ies);
+ if (!ies)
return NULL;
- return cfg80211_find_ie(ie, bss->information_elements,
- bss->len_information_elements);
+
+ return cfg80211_find_ie(ie, ies->data, ies->len);
}
EXPORT_SYMBOL(ieee80211_bss_get_ie);
diff --git a/net/wireless/wext-sme.c b/net/wireless/wext-sme.c
index 873af63..fb9622f 100644
--- a/net/wireless/wext-sme.c
+++ b/net/wireless/wext-sme.c
@@ -242,13 +242,17 @@
wdev_lock(wdev);
if (wdev->current_bss) {
- const u8 *ie = ieee80211_bss_get_ie(&wdev->current_bss->pub,
- WLAN_EID_SSID);
+ const u8 *ie;
+
+ rcu_read_lock();
+ ie = ieee80211_bss_get_ie(&wdev->current_bss->pub,
+ WLAN_EID_SSID);
if (ie) {
data->flags = 1;
data->length = ie[1];
memcpy(ssid, ie + 2, data->length);
}
+ rcu_read_unlock();
} else if (wdev->wext.connect.ssid && wdev->wext.connect.ssid_len) {
data->flags = 1;
data->length = wdev->wext.connect.ssid_len;