4.14-stable review patch. If anyone has any objections, please let me know.
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From: Wen Gong quic_wgong@quicinc.com
[ Upstream commit 61304336c67358d49a989e5e0060d8c99bad6ca8 ]
Lower layer device driver stop/wake TX by calling ieee80211_stop_queue()/ ieee80211_wake_queue() while hw scan. Sometimes hw scan and PTK rekey are running in parallel, when M4 sent from wpa_supplicant arrive while the TX queue is stopped, then the M4 will pending send, and then new key install from wpa_supplicant. After TX queue wake up by lower layer device driver, the M4 will be dropped by below call stack.
When key install started, the current key flag is set KEY_FLAG_TAINTED in ieee80211_pairwise_rekey(), and then mac80211 wait key install complete by lower layer device driver. Meanwhile ieee80211_tx_h_select_key() will return TX_DROP for the M4 in step 12 below, and then ieee80211_free_txskb() called by ieee80211_tx_dequeue(), so the M4 will not send and free, then the rekey process failed becaue AP not receive M4. Please see details in steps below.
There are a interval between KEY_FLAG_TAINTED set for current key flag and install key complete by lower layer device driver, the KEY_FLAG_TAINTED is set in this interval, all packet including M4 will be dropped in this interval, the interval is step 8~13 as below.
issue steps: TX thread install key thread 1. stop_queue -idle- 2. sending M4 -idle- 3. M4 pending -idle- 4. -idle- starting install key from wpa_supplicant 5. -idle- =>ieee80211_key_replace() 6. -idle- =>ieee80211_pairwise_rekey() and set currently key->flags |= KEY_FLAG_TAINTED 7. -idle- =>ieee80211_key_enable_hw_accel() 8. -idle- =>drv_set_key() and waiting key install complete from lower layer device driver 9. wake_queue -waiting state- 10. re-sending M4 -waiting state- 11. =>ieee80211_tx_h_select_key() -waiting state- 12. drop M4 by KEY_FLAG_TAINTED -waiting state- 13. -idle- install key complete with success/fail success: clear flag KEY_FLAG_TAINTED fail: start disconnect
Hence add check in step 11 above to allow the EAPOL send out in the interval. If lower layer device driver use the old key/cipher to encrypt the M4, then AP received/decrypt M4 correctly, after M4 send out, lower layer device driver install the new key/cipher to hardware and return success.
If lower layer device driver use new key/cipher to send the M4, then AP will/should drop the M4, then it is same result with this issue, AP will/ should kick out station as well as this issue.
issue log: kworker/u16:4-5238 [000] 6456.108926: stop_queue: phy1 queue:0, reason:0 wpa_supplicant-961 [003] 6456.119737: rdev_tx_control_port: wiphy_name=phy1 name=wlan0 ifindex=6 dest=ARRAY[9e, 05, 31, 20, 9b, d0] proto=36488 unencrypted=0 wpa_supplicant-961 [003] 6456.119839: rdev_return_int_cookie: phy1, returned 0, cookie: 504 wpa_supplicant-961 [003] 6456.120287: rdev_add_key: phy1, netdev:wlan0(6), key_index: 0, mode: 0, pairwise: true, mac addr: 9e:05:31:20:9b:d0 wpa_supplicant-961 [003] 6456.120453: drv_set_key: phy1 vif:wlan0(2) sta:9e:05:31:20:9b:d0 cipher:0xfac04, flags=0x9, keyidx=0, hw_key_idx=0 kworker/u16:9-3829 [001] 6456.168240: wake_queue: phy1 queue:0, reason:0 kworker/u16:9-3829 [001] 6456.168255: drv_wake_tx_queue: phy1 vif:wlan0(2) sta:9e:05:31:20:9b:d0 ac:0 tid:7 kworker/u16:9-3829 [001] 6456.168305: cfg80211_control_port_tx_status: wdev(1), cookie: 504, ack: false wpa_supplicant-961 [003] 6459.167982: drv_return_int: phy1 - -110
issue call stack: nl80211_frame_tx_status+0x230/0x340 [cfg80211] cfg80211_control_port_tx_status+0x1c/0x28 [cfg80211] ieee80211_report_used_skb+0x374/0x3e8 [mac80211] ieee80211_free_txskb+0x24/0x40 [mac80211] ieee80211_tx_dequeue+0x644/0x954 [mac80211] ath10k_mac_tx_push_txq+0xac/0x238 [ath10k_core] ath10k_mac_op_wake_tx_queue+0xac/0xe0 [ath10k_core] drv_wake_tx_queue+0x80/0x168 [mac80211] __ieee80211_wake_txqs+0xe8/0x1c8 [mac80211] _ieee80211_wake_txqs+0xb4/0x120 [mac80211] ieee80211_wake_txqs+0x48/0x80 [mac80211] tasklet_action_common+0xa8/0x254 tasklet_action+0x2c/0x38 __do_softirq+0xdc/0x384
Signed-off-by: Wen Gong quic_wgong@quicinc.com Link: https://lore.kernel.org/r/20230801064751.25803-1-quic_wgong@quicinc.com Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/mac80211/tx.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 7e62a55a03de1..3914214dee05a 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -650,7 +650,8 @@ ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx) }
if (unlikely(tx->key && tx->key->flags & KEY_FLAG_TAINTED && - !ieee80211_is_deauth(hdr->frame_control))) + !ieee80211_is_deauth(hdr->frame_control)) && + tx->skb->protocol != tx->sdata->control_port_protocol) return TX_DROP;
if (!skip_hw && tx->key &&