From: Javier Cardona <javier@cozybit.com>
Date: Mon, 29 Aug 2011 20:23:03 +0000 (-0700)
Subject: mac80211: Fix RCU pointer dereference in mesh_path_discard_frame()
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=af089c15cb13e1c5d984e41f495c8363dd5b1e30;p=linux-beck.git

mac80211: Fix RCU pointer dereference in mesh_path_discard_frame()

Reported by Pedro Larbig (ASPj)

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---

diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c
index ede4f5242e0b..2218eaf48bcb 100644
--- a/net/mac80211/mesh_pathtbl.c
+++ b/net/mac80211/mesh_pathtbl.c
@@ -991,9 +991,14 @@ void mesh_path_discard_frame(struct sk_buff *skb,
 
 		da = hdr->addr3;
 		ra = hdr->addr1;
+		rcu_read_lock();
 		mpath = mesh_path_lookup(da, sdata);
-		if (mpath)
+		if (mpath) {
+			spin_lock_bh(&mpath->state_lock);
 			sn = ++mpath->sn;
+			spin_unlock_bh(&mpath->state_lock);
+		}
+		rcu_read_unlock();
 		mesh_path_error_tx(sdata->u.mesh.mshcfg.element_ttl, skb->data,
 				   cpu_to_le32(sn), reason, ra, sdata);
 	}