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Date:   Tue, 16 Oct 2018 23:23:47 +0300
From:   Matias Karhumaa <matias.karhumaa@gmail.com>
To:     linux-bluetooth@vger.kernel.org
Subject: [PATCH 09/12] btmon: fix segfault caused by buffer over-read
Message-ID: <20181016202347.GA85019@Matias-MacBook-Air.local>
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Fix segfault caused by buffer over-read in btmon. Fix is to check in
packet_monitor() that index is not bigger than MAX_INDEX before accessing
index_list.

Crash was found by fuzzing btmon with AFL.
---
 monitor/packet.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/monitor/packet.c b/monitor/packet.c
index 1e9f9d9e4..2d8e15597 100644
--- a/monitor/packet.c
+++ b/monitor/packet.c
@@ -3864,6 +3864,11 @@ void packet_monitor(struct timeval *tv, struct ucred *cred,
 		index_current = index;
 	}
 
+	if (index != HCI_DEV_NONE && index > MAX_INDEX) {
+		print_field("Invalid index (%d)", index);
+		return;
+	}
+
 	if (tv && time_offset == ((time_t) -1))
 		time_offset = tv->tv_sec;
 
-- 
2.17.1