diff options
| author | Sara Sharon <sara.sharon@intel.com> | 2019-10-04 15:37:06 +0300 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2019-10-07 22:35:57 +0300 |
| commit | 461c4c2b4c0731d7452bad4e77c0cdbdcea1804c (patch) | |
| tree | 17ec48a63c1aa9d72ed5c50bc1e6abc65caa3afd /net/wireless/scan.c | |
| parent | 1399c59fa92984836db90538cf92397fe7caaa57 (diff) | |
| download | linux-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.c | 23 |
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; } |