Message ID | 20190820151956.22628-2-connor.kuehl@canonical.com |
---|---|
State | New |
Headers | show |
Series | Fix for CVE-2019-0136 | expand |
On 20.08.19 17:19, Connor Kuehl wrote: > From: Yu Wang <yyuwang@codeaurora.org> > > CVE-2019-0136 > > When receiving a deauthentication/disassociation frame from a TDLS > peer, a station should not disconnect the current AP, but only > disable the current TDLS link if it's enabled. > > Without this change, a TDLS issue can be reproduced by following the > steps as below: > > 1. STA-1 and STA-2 are connected to AP, bidirection traffic is running > between STA-1 and STA-2. > 2. Set up TDLS link between STA-1 and STA-2, stay for a while, then > teardown TDLS link. > 3. Repeat step #2 and monitor the connection between STA and AP. > > During the test, one STA may send a deauthentication/disassociation > frame to another, after TDLS teardown, with reason code 6/7, which > means: Class 2/3 frame received from nonassociated STA. > > On receive this frame, the receiver STA will disconnect the current > AP and then reconnect. It's not a expected behavior, purpose of this > frame should be disabling the TDLS link, not the link with AP. > > Cc: stable@vger.kernel.org > Signed-off-by: Yu Wang <yyuwang@codeaurora.org> > Signed-off-by: Johannes Berg <johannes.berg@intel.com> > (backported from commit 79c92ca42b5a3e0ea172ea2ce8df8e125af237da) > [ Connor Kuehl: the patch context differed slightly in the new addition > to ieee80211_rx_mgmt_disassoc(). Mainline commit 68506e9af132 > "mac80211: Print text for disassociation reason" introduces some more > information to the call to sdata_info() but Xenial does not contain that > commit and it is not necessary to fix this CVE. So, that hunk was placed > manually and the call to sdata_info() remains the same as it was before. ] > Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com> Acked-by: Stefan Bader <stefan.bader@canonical.com> > --- tl;dr is minor context adjustment > net/mac80211/ieee80211_i.h | 3 +++ > net/mac80211/mlme.c | 12 +++++++++++- > net/mac80211/tdls.c | 23 +++++++++++++++++++++++ > 3 files changed, 37 insertions(+), 1 deletion(-) > > diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h > index 7b271f3ded6b..72f76da88912 100644 > --- a/net/mac80211/ieee80211_i.h > +++ b/net/mac80211/ieee80211_i.h > @@ -2059,6 +2059,9 @@ void ieee80211_tdls_cancel_channel_switch(struct wiphy *wiphy, > const u8 *addr); > void ieee80211_teardown_tdls_peers(struct ieee80211_sub_if_data *sdata); > void ieee80211_tdls_chsw_work(struct work_struct *wk); > +void ieee80211_tdls_handle_disconnect(struct ieee80211_sub_if_data *sdata, > + const u8 *peer, u16 reason); > +const char *ieee80211_get_reason_code_string(u16 reason_code); > > extern const struct ethtool_ops ieee80211_ethtool_ops; > > diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c > index 08384dbf426c..d9536226d12a 100644 > --- a/net/mac80211/mlme.c > +++ b/net/mac80211/mlme.c > @@ -2733,7 +2733,7 @@ static void ieee80211_rx_mgmt_auth(struct ieee80211_sub_if_data *sdata, > #define case_WLAN(type) \ > case WLAN_REASON_##type: return #type > > -static const char *ieee80211_get_reason_code_string(u16 reason_code) > +const char *ieee80211_get_reason_code_string(u16 reason_code) > { > switch (reason_code) { > case_WLAN(UNSPECIFIED); > @@ -2798,6 +2798,11 @@ static void ieee80211_rx_mgmt_deauth(struct ieee80211_sub_if_data *sdata, > if (len < 24 + 2) > return; > > + if (!ether_addr_equal(mgmt->bssid, mgmt->sa)) { > + ieee80211_tdls_handle_disconnect(sdata, mgmt->sa, reason_code); > + return; > + } > + > if (ifmgd->associated && > ether_addr_equal(mgmt->bssid, ifmgd->associated->bssid)) { > const u8 *bssid = ifmgd->associated->bssid; > @@ -2847,6 +2852,11 @@ static void ieee80211_rx_mgmt_disassoc(struct ieee80211_sub_if_data *sdata, > > reason_code = le16_to_cpu(mgmt->u.disassoc.reason_code); > > + if (!ether_addr_equal(mgmt->bssid, mgmt->sa)) { > + ieee80211_tdls_handle_disconnect(sdata, mgmt->sa, reason_code); > + return; > + } > + > sdata_info(sdata, "disassociated from %pM (Reason: %u)\n", > mgmt->sa, reason_code); > > diff --git a/net/mac80211/tdls.c b/net/mac80211/tdls.c > index c9eeb3f12808..ce2ece424384 100644 > --- a/net/mac80211/tdls.c > +++ b/net/mac80211/tdls.c > @@ -1963,3 +1963,26 @@ void ieee80211_tdls_chsw_work(struct work_struct *wk) > } > rtnl_unlock(); > } > + > +void ieee80211_tdls_handle_disconnect(struct ieee80211_sub_if_data *sdata, > + const u8 *peer, u16 reason) > +{ > + struct ieee80211_sta *sta; > + > + rcu_read_lock(); > + sta = ieee80211_find_sta(&sdata->vif, peer); > + if (!sta || !sta->tdls) { > + rcu_read_unlock(); > + return; > + } > + rcu_read_unlock(); > + > + tdls_dbg(sdata, "disconnected from TDLS peer %pM (Reason: %u=%s)\n", > + peer, reason, > + ieee80211_get_reason_code_string(reason)); > + > + ieee80211_tdls_oper_request(&sdata->vif, peer, > + NL80211_TDLS_TEARDOWN, > + WLAN_REASON_TDLS_TEARDOWN_UNREACHABLE, > + GFP_ATOMIC); > +} >
On 8/20/19 5:19 PM, Connor Kuehl wrote: > From: Yu Wang <yyuwang@codeaurora.org> > > CVE-2019-0136 > > When receiving a deauthentication/disassociation frame from a TDLS > peer, a station should not disconnect the current AP, but only > disable the current TDLS link if it's enabled. > > Without this change, a TDLS issue can be reproduced by following the > steps as below: > > 1. STA-1 and STA-2 are connected to AP, bidirection traffic is running > between STA-1 and STA-2. > 2. Set up TDLS link between STA-1 and STA-2, stay for a while, then > teardown TDLS link. > 3. Repeat step #2 and monitor the connection between STA and AP. > > During the test, one STA may send a deauthentication/disassociation > frame to another, after TDLS teardown, with reason code 6/7, which > means: Class 2/3 frame received from nonassociated STA. > > On receive this frame, the receiver STA will disconnect the current > AP and then reconnect. It's not a expected behavior, purpose of this > frame should be disabling the TDLS link, not the link with AP. > > Cc: stable@vger.kernel.org > Signed-off-by: Yu Wang <yyuwang@codeaurora.org> > Signed-off-by: Johannes Berg <johannes.berg@intel.com> > (backported from commit 79c92ca42b5a3e0ea172ea2ce8df8e125af237da) > [ Connor Kuehl: the patch context differed slightly in the new addition > to ieee80211_rx_mgmt_disassoc(). Mainline commit 68506e9af132 > "mac80211: Print text for disassociation reason" introduces some more > information to the call to sdata_info() but Xenial does not contain that > commit and it is not necessary to fix this CVE. So, that hunk was placed > manually and the call to sdata_info() remains the same as it was before. ] > Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com> Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com> > --- > net/mac80211/ieee80211_i.h | 3 +++ > net/mac80211/mlme.c | 12 +++++++++++- > net/mac80211/tdls.c | 23 +++++++++++++++++++++++ > 3 files changed, 37 insertions(+), 1 deletion(-) > > diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h > index 7b271f3ded6b..72f76da88912 100644 > --- a/net/mac80211/ieee80211_i.h > +++ b/net/mac80211/ieee80211_i.h > @@ -2059,6 +2059,9 @@ void ieee80211_tdls_cancel_channel_switch(struct wiphy *wiphy, > const u8 *addr); > void ieee80211_teardown_tdls_peers(struct ieee80211_sub_if_data *sdata); > void ieee80211_tdls_chsw_work(struct work_struct *wk); > +void ieee80211_tdls_handle_disconnect(struct ieee80211_sub_if_data *sdata, > + const u8 *peer, u16 reason); > +const char *ieee80211_get_reason_code_string(u16 reason_code); > > extern const struct ethtool_ops ieee80211_ethtool_ops; > > diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c > index 08384dbf426c..d9536226d12a 100644 > --- a/net/mac80211/mlme.c > +++ b/net/mac80211/mlme.c > @@ -2733,7 +2733,7 @@ static void ieee80211_rx_mgmt_auth(struct ieee80211_sub_if_data *sdata, > #define case_WLAN(type) \ > case WLAN_REASON_##type: return #type > > -static const char *ieee80211_get_reason_code_string(u16 reason_code) > +const char *ieee80211_get_reason_code_string(u16 reason_code) > { > switch (reason_code) { > case_WLAN(UNSPECIFIED); > @@ -2798,6 +2798,11 @@ static void ieee80211_rx_mgmt_deauth(struct ieee80211_sub_if_data *sdata, > if (len < 24 + 2) > return; > > + if (!ether_addr_equal(mgmt->bssid, mgmt->sa)) { > + ieee80211_tdls_handle_disconnect(sdata, mgmt->sa, reason_code); > + return; > + } > + > if (ifmgd->associated && > ether_addr_equal(mgmt->bssid, ifmgd->associated->bssid)) { > const u8 *bssid = ifmgd->associated->bssid; > @@ -2847,6 +2852,11 @@ static void ieee80211_rx_mgmt_disassoc(struct ieee80211_sub_if_data *sdata, > > reason_code = le16_to_cpu(mgmt->u.disassoc.reason_code); > > + if (!ether_addr_equal(mgmt->bssid, mgmt->sa)) { > + ieee80211_tdls_handle_disconnect(sdata, mgmt->sa, reason_code); > + return; > + } > + > sdata_info(sdata, "disassociated from %pM (Reason: %u)\n", > mgmt->sa, reason_code); > > diff --git a/net/mac80211/tdls.c b/net/mac80211/tdls.c > index c9eeb3f12808..ce2ece424384 100644 > --- a/net/mac80211/tdls.c > +++ b/net/mac80211/tdls.c > @@ -1963,3 +1963,26 @@ void ieee80211_tdls_chsw_work(struct work_struct *wk) > } > rtnl_unlock(); > } > + > +void ieee80211_tdls_handle_disconnect(struct ieee80211_sub_if_data *sdata, > + const u8 *peer, u16 reason) > +{ > + struct ieee80211_sta *sta; > + > + rcu_read_lock(); > + sta = ieee80211_find_sta(&sdata->vif, peer); > + if (!sta || !sta->tdls) { > + rcu_read_unlock(); > + return; > + } > + rcu_read_unlock(); > + > + tdls_dbg(sdata, "disconnected from TDLS peer %pM (Reason: %u=%s)\n", > + peer, reason, > + ieee80211_get_reason_code_string(reason)); > + > + ieee80211_tdls_oper_request(&sdata->vif, peer, > + NL80211_TDLS_TEARDOWN, > + WLAN_REASON_TDLS_TEARDOWN_UNREACHABLE, > + GFP_ATOMIC); > +} >
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 7b271f3ded6b..72f76da88912 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -2059,6 +2059,9 @@ void ieee80211_tdls_cancel_channel_switch(struct wiphy *wiphy, const u8 *addr); void ieee80211_teardown_tdls_peers(struct ieee80211_sub_if_data *sdata); void ieee80211_tdls_chsw_work(struct work_struct *wk); +void ieee80211_tdls_handle_disconnect(struct ieee80211_sub_if_data *sdata, + const u8 *peer, u16 reason); +const char *ieee80211_get_reason_code_string(u16 reason_code); extern const struct ethtool_ops ieee80211_ethtool_ops; diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 08384dbf426c..d9536226d12a 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -2733,7 +2733,7 @@ static void ieee80211_rx_mgmt_auth(struct ieee80211_sub_if_data *sdata, #define case_WLAN(type) \ case WLAN_REASON_##type: return #type -static const char *ieee80211_get_reason_code_string(u16 reason_code) +const char *ieee80211_get_reason_code_string(u16 reason_code) { switch (reason_code) { case_WLAN(UNSPECIFIED); @@ -2798,6 +2798,11 @@ static void ieee80211_rx_mgmt_deauth(struct ieee80211_sub_if_data *sdata, if (len < 24 + 2) return; + if (!ether_addr_equal(mgmt->bssid, mgmt->sa)) { + ieee80211_tdls_handle_disconnect(sdata, mgmt->sa, reason_code); + return; + } + if (ifmgd->associated && ether_addr_equal(mgmt->bssid, ifmgd->associated->bssid)) { const u8 *bssid = ifmgd->associated->bssid; @@ -2847,6 +2852,11 @@ static void ieee80211_rx_mgmt_disassoc(struct ieee80211_sub_if_data *sdata, reason_code = le16_to_cpu(mgmt->u.disassoc.reason_code); + if (!ether_addr_equal(mgmt->bssid, mgmt->sa)) { + ieee80211_tdls_handle_disconnect(sdata, mgmt->sa, reason_code); + return; + } + sdata_info(sdata, "disassociated from %pM (Reason: %u)\n", mgmt->sa, reason_code); diff --git a/net/mac80211/tdls.c b/net/mac80211/tdls.c index c9eeb3f12808..ce2ece424384 100644 --- a/net/mac80211/tdls.c +++ b/net/mac80211/tdls.c @@ -1963,3 +1963,26 @@ void ieee80211_tdls_chsw_work(struct work_struct *wk) } rtnl_unlock(); } + +void ieee80211_tdls_handle_disconnect(struct ieee80211_sub_if_data *sdata, + const u8 *peer, u16 reason) +{ + struct ieee80211_sta *sta; + + rcu_read_lock(); + sta = ieee80211_find_sta(&sdata->vif, peer); + if (!sta || !sta->tdls) { + rcu_read_unlock(); + return; + } + rcu_read_unlock(); + + tdls_dbg(sdata, "disconnected from TDLS peer %pM (Reason: %u=%s)\n", + peer, reason, + ieee80211_get_reason_code_string(reason)); + + ieee80211_tdls_oper_request(&sdata->vif, peer, + NL80211_TDLS_TEARDOWN, + WLAN_REASON_TDLS_TEARDOWN_UNREACHABLE, + GFP_ATOMIC); +}