Merge tag 'for-net-2025-08-29' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth

Luiz Augusto von Dentz says:

====================
bluetooth pull request for net:

 - vhci: Prevent use-after-free by removing debugfs files early
 - L2CAP: Fix use-after-free in l2cap_sock_cleanup_listen()

* tag 'for-net-2025-08-29' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth:
  Bluetooth: Fix use-after-free in l2cap_sock_cleanup_listen()
  Bluetooth: vhci: Prevent use-after-free by removing debugfs files early
====================

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: kuba-moo

drivers/bluetooth/hci_vhci.c

@@ -380,6 +380,28 @@ static const struct file_operations force_devcoredump_fops = {
 	.write		= force_devcd_write,
 };
 
+static void vhci_debugfs_init(struct vhci_data *data)
+{
+	struct hci_dev *hdev = data->hdev;
+
+	debugfs_create_file("force_suspend", 0644, hdev->debugfs, data,
+			    &force_suspend_fops);
+
+	debugfs_create_file("force_wakeup", 0644, hdev->debugfs, data,
+			    &force_wakeup_fops);
+
+	if (IS_ENABLED(CONFIG_BT_MSFTEXT))
+		debugfs_create_file("msft_opcode", 0644, hdev->debugfs, data,
+				    &msft_opcode_fops);
+
+	if (IS_ENABLED(CONFIG_BT_AOSPEXT))
+		debugfs_create_file("aosp_capable", 0644, hdev->debugfs, data,
+				    &aosp_capable_fops);
+
+	debugfs_create_file("force_devcoredump", 0644, hdev->debugfs, data,
+			    &force_devcoredump_fops);
+}
+
 static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
 {
 	struct hci_dev *hdev;
@@ -434,22 +456,8 @@ static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
 		return -EBUSY;
 	}
 
-	debugfs_create_file("force_suspend", 0644, hdev->debugfs, data,
-			    &force_suspend_fops);
-
-	debugfs_create_file("force_wakeup", 0644, hdev->debugfs, data,
-			    &force_wakeup_fops);
-
-	if (IS_ENABLED(CONFIG_BT_MSFTEXT))
-		debugfs_create_file("msft_opcode", 0644, hdev->debugfs, data,
-				    &msft_opcode_fops);
-
-	if (IS_ENABLED(CONFIG_BT_AOSPEXT))
-		debugfs_create_file("aosp_capable", 0644, hdev->debugfs, data,
-				    &aosp_capable_fops);
-
-	debugfs_create_file("force_devcoredump", 0644, hdev->debugfs, data,
-			    &force_devcoredump_fops);
+	if (!IS_ERR_OR_NULL(hdev->debugfs))
+		vhci_debugfs_init(data);
 
 	hci_skb_pkt_type(skb) = HCI_VENDOR_PKT;
 
@@ -651,6 +659,21 @@ static int vhci_open(struct inode *inode, struct file *file)
 	return 0;
 }
 
+static void vhci_debugfs_remove(struct hci_dev *hdev)
+{
+	debugfs_lookup_and_remove("force_suspend", hdev->debugfs);
+
+	debugfs_lookup_and_remove("force_wakeup", hdev->debugfs);
+
+	if (IS_ENABLED(CONFIG_BT_MSFTEXT))
+		debugfs_lookup_and_remove("msft_opcode", hdev->debugfs);
+
+	if (IS_ENABLED(CONFIG_BT_AOSPEXT))
+		debugfs_lookup_and_remove("aosp_capable", hdev->debugfs);
+
+	debugfs_lookup_and_remove("force_devcoredump", hdev->debugfs);
+}
+
 static int vhci_release(struct inode *inode, struct file *file)
 {
 	struct vhci_data *data = file->private_data;
@@ -662,6 +685,8 @@ static int vhci_release(struct inode *inode, struct file *file)
 	hdev = data->hdev;
 
 	if (hdev) {
+		if (!IS_ERR_OR_NULL(hdev->debugfs))
+			vhci_debugfs_remove(hdev);
 		hci_unregister_dev(hdev);
 		hci_free_dev(hdev);
 	}

net/bluetooth/l2cap_sock.c

@@ -1422,7 +1422,10 @@ static int l2cap_sock_release(struct socket *sock)
 	if (!sk)
 		return 0;
 
+	lock_sock_nested(sk, L2CAP_NESTING_PARENT);
 	l2cap_sock_cleanup_listen(sk);
+	release_sock(sk);
+
 	bt_sock_unlink(&l2cap_sk_list, sk);
 
 	err = l2cap_sock_shutdown(sock, SHUT_RDWR);