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authorSara Sharon <sara.sharon@intel.com>2019-10-04 15:37:06 +0300
committerJohannes Berg <johannes.berg@intel.com>2019-10-07 22:35:57 +0300
commit461c4c2b4c0731d7452bad4e77c0cdbdcea1804c (patch)
tree17ec48a63c1aa9d72ed5c50bc1e6abc65caa3afd /net/wireless/scan.c
parent1399c59fa92984836db90538cf92397fe7caaa57 (diff)
downloadlinux-461c4c2b4c0731d7452bad4e77c0cdbdcea1804c.tar.xz
cfg80211: fix a bunch of RCU issues in multi-bssid code
cfg80211_update_notlisted_nontrans() leaves the RCU critical session too early, while still using nontrans_ssid which is RCU protected. In addition, it performs a bunch of RCU pointer update operations such as rcu_access_pointer and rcu_assign_pointer. The caller, cfg80211_inform_bss_frame_data(), also accesses the RCU pointer without holding the lock. Just wrap all of this with bss_lock. Signed-off-by: Sara Sharon <sara.sharon@intel.com> Signed-off-by: Luca Coelho <luciano.coelho@intel.com> Link: https://lore.kernel.org/r/20191004123706.15768-3-luca@coelho.fi Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/wireless/scan.c')
-rw-r--r--net/wireless/scan.c23
1 files changed, 13 insertions, 10 deletions
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index ff1016607f0b..aef240fdf8df 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -1703,8 +1703,7 @@ cfg80211_parse_mbssid_frame_data(struct wiphy *wiphy,
static void
cfg80211_update_notlisted_nontrans(struct wiphy *wiphy,
struct cfg80211_bss *nontrans_bss,
- struct ieee80211_mgmt *mgmt, size_t len,
- gfp_t gfp)
+ struct ieee80211_mgmt *mgmt, size_t len)
{
u8 *ie, *new_ie, *pos;
const u8 *nontrans_ssid, *trans_ssid, *mbssid;
@@ -1715,6 +1714,8 @@ cfg80211_update_notlisted_nontrans(struct wiphy *wiphy,
const struct cfg80211_bss_ies *old;
u8 cpy_len;
+ lockdep_assert_held(&wiphy_to_rdev(wiphy)->bss_lock);
+
ie = mgmt->u.probe_resp.variable;
new_ie_len = ielen;
@@ -1731,23 +1732,22 @@ cfg80211_update_notlisted_nontrans(struct wiphy *wiphy,
if (!mbssid || mbssid < trans_ssid)
return;
new_ie_len -= mbssid[1];
- rcu_read_lock();
+
nontrans_ssid = ieee80211_bss_get_ie(nontrans_bss, WLAN_EID_SSID);
- if (!nontrans_ssid) {
- rcu_read_unlock();
+ if (!nontrans_ssid)
return;
- }
+
new_ie_len += nontrans_ssid[1];
- rcu_read_unlock();
/* generate new ie for nontrans BSS
* 1. replace SSID with nontrans BSS' SSID
* 2. skip MBSSID IE
*/
- new_ie = kzalloc(new_ie_len, gfp);
+ new_ie = kzalloc(new_ie_len, GFP_ATOMIC);
if (!new_ie)
return;
- new_ies = kzalloc(sizeof(*new_ies) + new_ie_len, gfp);
+
+ new_ies = kzalloc(sizeof(*new_ies) + new_ie_len, GFP_ATOMIC);
if (!new_ies)
goto out_free;
@@ -1901,6 +1901,8 @@ cfg80211_inform_bss_frame_data(struct wiphy *wiphy,
cfg80211_parse_mbssid_frame_data(wiphy, data, mgmt, len,
&non_tx_data, gfp);
+ spin_lock_bh(&wiphy_to_rdev(wiphy)->bss_lock);
+
/* check if the res has other nontransmitting bss which is not
* in MBSSID IE
*/
@@ -1915,8 +1917,9 @@ cfg80211_inform_bss_frame_data(struct wiphy *wiphy,
ies2 = rcu_access_pointer(tmp_bss->ies);
if (ies2->tsf < ies1->tsf)
cfg80211_update_notlisted_nontrans(wiphy, tmp_bss,
- mgmt, len, gfp);
+ mgmt, len);
}
+ spin_unlock_bh(&wiphy_to_rdev(wiphy)->bss_lock);
return res;
}