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From:   Luiz Augusto von Dentz <luiz.dentz@gmail.com>
To:     linux-bluetooth@vger.kernel.org
Subject: [PATCH] Bluetooth: L2CAP: Fix attempting to access uninitialized memory
Date:   Mon, 31 Oct 2022 16:10:52 -0700
Message-Id: <20221031231052.2718430-1-luiz.dentz@gmail.com>
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From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

On l2cap_parse_conf_req the variable efs is only initialized if
remote_efs has been set.

CVE: CVE-2022-42895
CC: stable@vger.kernel.org
Reported-by: Tamás Koczka <poprdi@google.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
 net/bluetooth/l2cap_core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index cdddd2c779f2..93802b27f2a5 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -3764,7 +3764,8 @@ static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data, size_t data
 			l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC,
 					   sizeof(rfc), (unsigned long) &rfc, endptr - ptr);
 
-			if (test_bit(FLAG_EFS_ENABLE, &chan->flags)) {
+			if (remote_efs &&
+			    test_bit(FLAG_EFS_ENABLE, &chan->flags)) {
 				chan->remote_id = efs.id;
 				chan->remote_stype = efs.stype;
 				chan->remote_msdu = le16_to_cpu(efs.msdu);
-- 
2.37.3