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From: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
To: linux-bluetooth@vger.kernel.org
Subject: [PATCH v1 4/4] Bluetooth: bnep: Fix out-of-bound access
Date: Wed, 28 Feb 2024 12:18:38 -0500
Message-ID: <20240228171838.2414532-4-luiz.dentz@gmail.com>
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From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

This fixes attempting to access past ethhdr.h_source, although it seems
intentional to copy also the contents of h_proto this triggers
out-of-bound access problems with the likes of static analyzer, so this
instead just copy ETH_ALEN and then proceed to use put_unaligned to copy
h_proto separetely.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
 net/bluetooth/bnep/core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/bluetooth/bnep/core.c b/net/bluetooth/bnep/core.c
index 5a6a49885ab6..a660c428e220 100644
--- a/net/bluetooth/bnep/core.c
+++ b/net/bluetooth/bnep/core.c
@@ -385,7 +385,8 @@ static int bnep_rx_frame(struct bnep_session *s, struct sk_buff *skb)
 
 	case BNEP_COMPRESSED_DST_ONLY:
 		__skb_put_data(nskb, skb_mac_header(skb), ETH_ALEN);
-		__skb_put_data(nskb, s->eh.h_source, ETH_ALEN + 2);
+		__skb_put_data(nskb, s->eh.h_source, ETH_ALEN);
+		put_unaligned(s->eh.h_proto, (__be16 *)__skb_put(nskb, 2));
 		break;
 
 	case BNEP_GENERAL:
-- 
2.43.0