From b3e7de873df77c1fa0bc2cfaf3eaff757b80e773 Mon Sep 17 00:00:00 2001
From: Bob Copeland <me@bobcopeland.com>
Date: Tue, 14 Jul 2015 08:31:56 -0400
Subject: [PATCH] mac80211: add missing length check for confirm frames
Although mesh_rx_plink_frame() already checks that frames have enough
bytes for the action code plus another two bytes for capability/reason
code, it doesn't take into account that confirm frames also have an
additional two-byte aid. As a result, a corrupt frame could cause a
subsequent subtraction to wrap around to ill effect. Add another
check for this case.
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
net/mac80211/mesh_plink.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/mac80211/mesh_plink.c b/net/mac80211/mesh_plink.c
index f17127e754c9..3b59099413fb 100644
--- a/net/mac80211/mesh_plink.c
+++ b/net/mac80211/mesh_plink.c
@@ -1122,6 +1122,9 @@ void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
WLAN_SP_MESH_PEERING_CONFIRM) {
baseaddr += 4;
baselen += 4;
+
+ if (baselen > len)
+ return;
}
ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems);
mesh_process_plink_frame(sdata, mgmt, &elems);
--
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