c94a934f3e1d4ff887d26df3c42b665bf55ef5eccada7955105c649d.patch

From fcf8f93b9c0c0e6d28a11ad2deb4de82263861d7 Mon Sep 17 00:00:00 2001
From: Soenke Huster <soenke.huster@eknoes.de>
Date: Fri, 14 Jan 2022 17:44:02 +0100
Subject: [PATCH] BACKPORT: FROMGIT: Bluetooth: fix null ptr deref on
 hci_sync_conn_complete_evt

This event is just specified for SCO and eSCO link types.
On the reception of a HCI_Synchronous_Connection_Complete for a BDADDR
of an existing LE connection, LE link type and a status that triggers the
second case of the packet processing a NULL pointer dereference happens,
as conn->link is NULL.

Signed-off-by: Soenke Huster <soenke.huster@eknoes.de>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

(cherry picked from commit 3afee2118132e93e5f6fa636dfde86201a860ab3
 https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git master)

Conflicts:
   net/bluetooth/hci_event.c
   bt_dev_dbg() was introduced by (3e54c5890c87 Bluetooth:
   hci_event: Use of a function table to handle HCI events).
   To resolve the conflict, we simply use BT_DBG().

BUG=b:196661726
TEST=C reproducer from b/196661726

Signed-off-by: Ying Hsu <yinghsu@chromium.org>
Change-Id: I6d0cd892f1f99259fff36c800eb409f8c6694382
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/3513794
Reviewed-by: Shyh-In Hwang <josephsih@chromium.org>
Reviewed-by: Archie Pusaka <apusaka@chromium.org>
---
 net/bluetooth/hci_event.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index d540b80d2a5b..43b4a7734b7c 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -4680,6 +4680,19 @@ static void hci_sync_conn_complete_evt(struct hci_dev *hdev, void *data,
 	struct hci_ev_sync_conn_complete *ev = data;
 	struct hci_conn *conn;
 
+	switch (ev->link_type) {
+	case SCO_LINK:
+	case ESCO_LINK:
+		break;
+	default:
+		/* As per Core 5.3 Vol 4 Part E 7.7.35 (p.2219), Link_Type
+		 * for HCI_Synchronous_Connection_Complete is limited to
+		 * either SCO or eSCO
+		 */
+		bt_dev_err(hdev, "Ignoring connect complete event for invalid link type");
+		return;
+	}
+
 	bt_dev_dbg(hdev, "status 0x%2.2x", ev->status);
 
 	hci_dev_lock(hdev);
-- 
2.35.1.723.g4982287a31-goog