usb: control buffer fixesusb-patches

Windows allows control transfers to pass up to 4k of data, so raise our
control buffer size to 4k. For control out transfers the usb core code copies
the control request data to a buffer before calling the device's handle_control
callback. Add a check for overflowing the buffer before copying the data.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>

2 files changed, 7 insertions, 1 deletions

diff --git a/hw/usb.c b/hw/usb.c
index b0264872d2..092a4a7ac3 100644
--- a/hw/usb.c
+++ b/hw/usb.c
@@ -98,6 +98,12 @@ static int do_token_setup(USBDevice *s, USBPacket *p)
             s->setup_len = ret;
         s->setup_state = SETUP_STATE_DATA;
     } else {
+        if (s->setup_len > sizeof(s->data_buf)) {
+            fprintf(stderr,
+                "usb_generic_handle_packet: ctrl buffer too small (%d > %zu)\n",
+                s->setup_len, sizeof(s->data_buf));
+            return USB_RET_STALL;
+        }
         if (s->setup_len == 0)
             s->setup_state = SETUP_STATE_ACK;
         else
diff --git a/hw/usb.h b/hw/usb.h
index 4ff931c7dd..6d6fd9e5ad 100644
--- a/hw/usb.h
+++ b/hw/usb.h
@@ -167,7 +167,7 @@ struct USBDevice {
 
     int32_t state;
     uint8_t setup_buf[8];
-    uint8_t data_buf[1024];
+    uint8_t data_buf[4096];
     int32_t remote_wakeup;
     int32_t setup_state;
     int32_t setup_len;