Bluetooth: Fix slab-out-of-bounds read in hci_extended_inquiry_result_evt()

commit 51c19bf3d5cfaa66571e4b88ba2a6f6295311101 upstream.

Check upon `num_rsp` is insufficient. A malformed event packet with a
large `num_rsp` number makes hci_extended_inquiry_result_evt() go out
of bounds. Fix it.

This patch fixes the following syzbot bug:

    https://syzkaller.appspot.com/bug?id=4bf11aa05c4ca51ce0df86e500fce486552dc8d2

Reported-by: syzbot+d8489a79b781849b9c46@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index a8aa3f2..0ce196b 100644 (file)
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -3826,7 +3826,7 @@ static void hci_extended_inquiry_result_evt(struct hci_dev *hdev,
 
        BT_DBG("%s num_rsp %d", hdev->name, num_rsp);
 
-       if (!num_rsp)
+       if (!num_rsp || skb->len < num_rsp * sizeof(*info) + 1)
                return;
 
        if (hci_dev_test_flag(hdev, HCI_PERIODIC_INQ))