[PULL 6/7] usb/xhci: sanity check packet size (CVE-2021-3527)

[Gerd Hoffmann <kraxel@redhat.com>]

Make sure the usb packet size is within the
bounds of the endpoint configuration.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-Id: <20210503132915.2335822-5-kraxel@redhat.com>
---
 hw/usb/hcd-xhci.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c
index 46212b1e695a..7acfb8137bc9 100644
--- a/hw/usb/hcd-xhci.c
+++ b/hw/usb/hcd-xhci.c
@@ -1568,6 +1568,11 @@ static int xhci_setup_packet(XHCITransfer *xfer)
         qemu_sglist_destroy(&xfer->sgl);
         return -1;
     }
+    if (xfer->packet.iov.size > ep->max_packet_size) {
+        usb_packet_unmap(&xfer->packet, &xfer->sgl);
+        qemu_sglist_destroy(&xfer->sgl);
+        return -1;
+    }
     DPRINTF("xhci: setup packet pid 0x%x addr %d ep %d\n",
             xfer->packet.pid, ep->dev->addr, ep->nr);
     return 0;
-- 
2.31.1