[SRU][PATCH][Xenial 1/1] Revert "Bluetooth: Align minimum encryption key size for LE and BR/EDR connections"

[Kleber Sacilotto de Souza]

From: Greg Kroah-Hartman <gregkh at linuxfoundation.org>

BugLink: https://bugs.launchpad.net/bugs/1833698

This reverts commit 07e38998a19d72b916c39a983c19134522ae806b which is
commit d5bb334a8e171b262e48f378bd2096c0ea458265 upstream.

Lots of people have reported issues with this patch, and as there does
not seem to be a fix going into Linus's kernel tree any time soon,
revert the commit in the stable trees so as to get people's machines
working properly again.

Reported-by: Vasily Khoruzhick <anarsoul at gmail.com>
Reported-by: Hans de Goede <hdegoede at redhat.com>
Cc: Jeremy Cline <jeremy at jcline.org>
Cc: Marcel Holtmann <marcel at holtmann.org>
Cc: Johan Hedberg <johan.hedberg at intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
(cherry picked from commit b528880e8b0167c34cb36c1b4e6165192f76267c linux-5.1.y)
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza at canonical.com>
---
 include/net/bluetooth/hci_core.h | 3 ---
 net/bluetooth/hci_conn.c         | 8 --------
 2 files changed, 11 deletions(-)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 5b82efbe8d3d..9c0aa27e3bf3 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -174,9 +174,6 @@ struct adv_info {
 
 #define HCI_MAX_SHORT_NAME_LENGTH	10
 
-/* Min encryption key size to match with SMP */
-#define HCI_MIN_ENC_KEY_SIZE		7
-
 /* Default LE RPA expiry time, 15 minutes */
 #define HCI_DEFAULT_RPA_TIMEOUT		(15 * 60)
 
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 83d4d574fa44..80be0ee17ff3 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -1177,14 +1177,6 @@ int hci_conn_check_link_mode(struct hci_conn *conn)
 	    !test_bit(HCI_CONN_ENCRYPT, &conn->flags))
 		return 0;
 
-	/* The minimum encryption key size needs to be enforced by the
-	 * host stack before establishing any L2CAP connections. The
-	 * specification in theory allows a minimum of 1, but to align
-	 * BR/EDR and LE transports, a minimum of 7 is chosen.
-	 */
-	if (conn->enc_key_size < HCI_MIN_ENC_KEY_SIZE)
-		return 0;
-
 	return 1;
 }
 
-- 
2.17.1