linux-kernel - [PATCH 2/4] Bluetooth: 6lowpan: fix BDADDR_LE vs ADDR_LE

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Message-ID: <0d953f217feaafb4ba40281c3ab87e18ad28bae7.1761998763.git.pav@iki.fi>
Date: Sat,  1 Nov 2025 14:09:12 +0200
From: Pauli Virtanen <pav@....fi>
To: linux-bluetooth@...r.kernel.org
Cc: Pauli Virtanen <pav@....fi>,
	marcel@...tmann.org,
	johan.hedberg@...il.com,
	luiz.dentz@...il.com,
	jukka.rissanen@...ux.intel.com,
	linux-kernel@...r.kernel.org
Subject: [PATCH 2/4] Bluetooth: 6lowpan: fix BDADDR_LE vs ADDR_LE_DEV address type confusion

Bluetooth 6lowpan.c confuses BDADDR_LE and ADDR_LE_DEV address types,
e.g. debugfs "connect" command takes the former, and "disconnect" and
"connect" to already connected device take the latter.  This is due to
using same value both for l2cap_chan_connect and hci_conn_hash_lookup_le
which take different dst_type values.

Fix address type passed to hci_conn_hash_lookup_le().

Retain the debugfs API difference between "connect" and "disconnect"
commands since it's been like this since 2015 and nobody apparently
complained.

Fixes: f5ad4ffceba0 ("Bluetooth: 6lowpan: Use hci_conn_hash_lookup_le() when possible")
Signed-off-by: Pauli Virtanen <pav@....fi>
---
 net/bluetooth/6lowpan.c | 28 ++++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
index f1d29fa4b411..0d8c2e2e9a6c 100644
--- a/net/bluetooth/6lowpan.c
+++ b/net/bluetooth/6lowpan.c
@@ -957,10 +957,11 @@ static struct l2cap_chan *bt_6lowpan_listen(void)
 }
 
 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
-			  struct l2cap_conn **conn)
+			  struct l2cap_conn **conn, bool disconnect)
 {
 	struct hci_conn *hcon;
 	struct hci_dev *hdev;
+	int le_addr_type;
 	int n;
 
 	n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
@@ -971,13 +972,32 @@ static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
 	if (n < 7)
 		return -EINVAL;
 
+	if (disconnect) {
+		/* The "disconnect" debugfs command has used different address
+		 * type constants than "connect" since 2015. Let's retain that
+		 * for now even though it's obviously buggy...
+		 */
+		*addr_type += 1;
+	}
+
+	switch (*addr_type) {
+	case BDADDR_LE_PUBLIC:
+		le_addr_type = ADDR_LE_DEV_PUBLIC;
+		break;
+	case BDADDR_LE_RANDOM:
+		le_addr_type = ADDR_LE_DEV_RANDOM;
+		break;
+	default:
+		return -EINVAL;
+	}
+
 	/* The LE_PUBLIC address type is ignored because of BDADDR_ANY */
 	hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC);
 	if (!hdev)
 		return -ENOENT;
 
 	hci_dev_lock(hdev);
-	hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type);
+	hcon = hci_conn_hash_lookup_le(hdev, addr, le_addr_type);
 	hci_dev_unlock(hdev);
 	hci_dev_put(hdev);
 
@@ -1104,7 +1124,7 @@ static ssize_t lowpan_control_write(struct file *fp,
 	buf[buf_size] = '\0';
 
 	if (memcmp(buf, "connect ", 8) == 0) {
-		ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
+		ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn, false);
 		if (ret == -EINVAL)
 			return ret;
 
@@ -1141,7 +1161,7 @@ static ssize_t lowpan_control_write(struct file *fp,
 	}
 
 	if (memcmp(buf, "disconnect ", 11) == 0) {
-		ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
+		ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn, true);
 		if (ret < 0)
 			return ret;
 
-- 
2.51.1