[PATCH] mac80211: allocate tailroom for forwarded mesh packets - Linux-stable-mirror

22 Feb 2019

Forwarded packets enter the tx path through ieee80211_add_pending_skb,
which skips the ieee80211_skb_resize call.
Fixes WARN_ON in ccmp_encrypt_skb and resulting packet loss.
Cc: stable@vger.kernel.org
Signed-off-by: Felix Fietkau nbd@nbd.name
---
 net/mac80211/rx.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 45aad3d3108c..d78c106ef314 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2644,6 +2644,7 @@ ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
    struct ieee80211_sub_if_data *sdata = rx->sdata;
    struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
    u16 ac, q, hdrlen;
+	int tailroom = 0;
hdr = (struct ieee80211_hdr *) skb->data;
    hdrlen = ieee80211_hdrlen(hdr->frame_control);
@@ -2730,8 +2731,12 @@ ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
    if (!ifmsh->mshcfg.dot11MeshForwarding)
    	goto out;
+	if (sdata->crypto_tx_tailroom_needed_cnt)
+		tailroom = IEEE80211_ENCRYPT_TAILROOM;
+
    fwd_skb = skb_copy_expand(skb, local->tx_headroom +
-				       sdata->encrypt_headroom, 0, GFP_ATOMIC);
+				       sdata->encrypt_headroom,
+				  tailroom, GFP_ATOMIC);
    if (!fwd_skb)
    	goto out;
-- 
2.17.0


    