From:   Alain Michaud <alainm@chromium.org>
To:     linux-bluetooth@vger.kernel.org
Cc:     Alain Michaud <alainm@chromium.org>, mcchou@chromium.org
Subject: [PATCH] Bluetooth: Fix adv set removal processing.
Date:   Mon, 15 Nov 2021 13:51:14 +0000
Message-Id: <20211115135114.2763223-1-alainm@chromium.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

When multiple advertisement sets are active and a single instance is
removed, the processing of hci_cc_le_set_ext_adv_enable will result in
considering all advertisements as disabled since the instance has
already been removed from the list.

The fix is to use the command parameters to validate the intent rather
than making an assumption based on the validity of the adv set.

remove_advertising() hci0

hci_req_add_ev() hci0 opcode 0x2039 plen 6
hci_req_add_ev() hci0 opcode 0x203c plen 1

hci_remove_adv_instance() hci0 removing 2MR
<-- This removes instance 2 from the adv_instances list

hci_cc_le_set_ext_adv_enable() hci0 status 0x00
hci_sent_cmd_data() hci0 opcode 0x2039
hci_cc_le_set_ext_adv_enable() adv instance 0, enabled 0
<-- This incorrectly assumes that all instances are
    being disabled while only handle 2 is being disabled.

hci_cc_le_set_ext_adv_enable() adv instance list status - before
hci_cc_le_set_ext_adv_enable() adv instance 3 is 1
hci_cc_le_set_ext_adv_enable() adv instance 1 is 1
hci_cc_le_set_ext_adv_enable() HCI_LE_ADV state before: 1
hci_cc_le_set_ext_adv_enable() adv instance list status - after
hci_cc_le_set_ext_adv_enable() adv instance 3 is 0
hci_cc_le_set_ext_adv_enable() adv instance 1 is 0
hci_cc_le_set_ext_adv_enable() HCI_LE_ADV state after: 0
<-- This is incorrect since handle 1 and 3 are still enabled
    in the controller

The fix was validated by running the ChromeOS bluetooth_AdapterAdvHealth
test suite.

Reviewed-by: mcchou@chromium.org
Signed-off-by: Alain Michaud <alainm@chromium.org>

---

 net/bluetooth/hci_event.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index d4b75a6cfeee..52161d04136f 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -1385,14 +1385,16 @@ static void hci_cc_le_set_ext_adv_enable(struct hci_dev *hdev,
 				if (adv->enabled)
 					goto unlock;
 			}
-		} else {
+
+			hci_dev_clear_flag(hdev, HCI_LE_ADV);
+		} else if (!cp->num_of_sets || !set->handle) {
 			/* All instances shall be considered disabled */
 			list_for_each_entry_safe(adv, n, &hdev->adv_instances,
 						 list)
 				adv->enabled = false;
-		}
 
-		hci_dev_clear_flag(hdev, HCI_LE_ADV);
+			hci_dev_clear_flag(hdev, HCI_LE_ADV);
+		}
 	}
 
 unlock:
-- 
2.34.0.rc1.387.gb447b232ab-goog