ath11k: Clear the fragment cache during key install

Currently the fragment cache setup during peer assoc is
cleared only during peer delete. In case a key reinstallation
happens with the same peer, the same fragment cache with old
fragments added before key installation could be clubbed
with fragments received after. This might be exploited
to mix fragments of different data resulting in a proper
unintended reassembled packet to be passed up the stack.

Hence flush the fragment cache on every key installation to prevent
potential attacks (CVE-2020-24587).

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.4.0.1-01734-QCAHKSWPL_SILICONZ-1 v2

Cc: stable@vger.kernel.org
Signed-off-by: Sriram R <srirrama@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Link: https://lore.kernel.org/r/20210511200110.218dc777836f.I9af6fc76215a35936c4152552018afb5079c5d8c@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath11k/dp_rx.c b/drivers/net/wireless/ath/ath11k/dp_rx.c
index 1d9aa1bb6b6e..3382f8bfcb48 100644
--- a/drivers/net/wireless/ath/ath11k/dp_rx.c
+++ b/drivers/net/wireless/ath/ath11k/dp_rx.c
@@ -852,6 +852,24 @@ static void ath11k_dp_rx_frags_cleanup(struct dp_rx_tid *rx_tid, bool rel_link_d
 	__skb_queue_purge(&rx_tid->rx_frags);
 }
 
+void ath11k_peer_frags_flush(struct ath11k *ar, struct ath11k_peer *peer)
+{
+	struct dp_rx_tid *rx_tid;
+	int i;
+
+	lockdep_assert_held(&ar->ab->base_lock);
+
+	for (i = 0; i <= IEEE80211_NUM_TIDS; i++) {
+		rx_tid = &peer->rx_tid[i];
+
+		spin_unlock_bh(&ar->ab->base_lock);
+		del_timer_sync(&rx_tid->frag_timer);
+		spin_lock_bh(&ar->ab->base_lock);
+
+		ath11k_dp_rx_frags_cleanup(rx_tid, true);
+	}
+}
+
 void ath11k_peer_rx_tid_cleanup(struct ath11k *ar, struct ath11k_peer *peer)
 {
 	struct dp_rx_tid *rx_tid;