mac80211: don't use napi_gro_receive() outside NAPI context

No matter how the driver manages its NAPI context, there's no way
sending frames to it from a timer can be correct, since it would
corrupt the internal GRO lists.

To avoid that, always use the non-NAPI path when releasing frames
from the timer.

Cc: stable@vger.kernel.org
Reported-by: Jean Trivelly <jean.trivelly@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

2 files changed, 6 insertions, 2 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index ab46ab4a7249..cdc374296245 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -205,6 +205,8 @@ enum ieee80211_packet_rx_flags {
  * @IEEE80211_RX_CMNTR: received on cooked monitor already
  * @IEEE80211_RX_BEACON_REPORTED: This frame was already reported
  *      to cfg80211_report_obss_beacon().
+ * @IEEE80211_RX_REORDER_TIMER: this frame is released by the
+ *      reorder buffer timeout timer, not the normal RX path
  *
  * These flags are used across handling multiple interfaces
  * for a single frame.
@@ -212,6 +214,7 @@ enum ieee80211_packet_rx_flags {
 enum ieee80211_rx_flags {
         IEEE80211_RX_CMNTR              = BIT(0),
         IEEE80211_RX_BEACON_REPORTED    = BIT(1),
+        IEEE80211_RX_REORDER_TIMER      = BIT(2),
 };
 
 struct ieee80211_rx_data {
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 260eed45b6d2..5793f75c5ffd 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2121,7 +2121,8 @@ ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
                 /* deliver to local stack */
                 skb->protocol = eth_type_trans(skb, dev);
                 memset(skb->cb, 0, sizeof(skb->cb));
-                if (rx->local->napi)
+                if (!(rx->flags & IEEE80211_RX_REORDER_TIMER) &&
+                    rx->local->napi)
                         napi_gro_receive(rx->local->napi, skb);
                 else
                         netif_receive_skb(skb);
@@ -3231,7 +3232,7 @@ void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid)
                 /* This is OK -- must be QoS data frame */
                 .security_idx = tid,
                 .seqno_idx = tid,
-                .flags = 0,
+                .flags = IEEE80211_RX_REORDER_TIMER,
         };
         struct tid_ampdu_rx *tid_agg_rx;