Re: [syzbot] [bluetooth?] KASAN: vmalloc-out-of-bounds Read in hci_devcd_dump

[Ivan Pravdin <ipravdin.official@gmail.com>]

#syz test

diff --git a/drivers/bluetooth/hci_vhci.c b/drivers/bluetooth/hci_vhci.c
index 59f4d7bdffdc..493d704c0dfb 100644
--- a/drivers/bluetooth/hci_vhci.c
+++ b/drivers/bluetooth/hci_vhci.c
@@ -661,6 +661,8 @@ static int vhci_release(struct inode *inode, struct file *file)
 
 	hdev = data->hdev;
 
+	debugfs_remove_recursive(hdev->debugfs);
+
 	if (hdev) {
 		hci_unregister_dev(hdev);
 		hci_free_dev(hdev);
diff --git a/net/bluetooth/coredump.c b/net/bluetooth/coredump.c
index 819eacb38762..1232c9a94f95 100644
--- a/net/bluetooth/coredump.c
+++ b/net/bluetooth/coredump.c
@@ -243,6 +243,7 @@ static void hci_devcd_handle_pkt_pattern(struct hci_dev *hdev,
 static void hci_devcd_dump(struct hci_dev *hdev)
 {
 	struct sk_buff *skb;
+	char *coredump;
 	u32 size;
 
 	bt_dev_dbg(hdev, "state %d", hdev->dump.state);
@@ -250,7 +251,11 @@ static void hci_devcd_dump(struct hci_dev *hdev)
 	size = hdev->dump.tail - hdev->dump.head;
 
 	/* Emit a devcoredump with the available data */
-	dev_coredumpv(&hdev->dev, hdev->dump.head, size, GFP_KERNEL);
+	coredump = vmalloc(size);
+	if (coredump) {
+		memcpy(coredump, hdev->dump.head, size);
+		dev_coredumpv(&hdev->dev, coredump, size, GFP_KERNEL);
+	}
 
 	/* Send a copy to monitor as a diagnostic packet */
 	skb = bt_skb_alloc(size, GFP_ATOMIC);

Ivan Pravdin