Security fix: check cumulative packet size for split device packets

1 files changed, 5 insertions, 0 deletions

diff --git a/daemon/device.c b/daemon/device.c
index 00c0340..7cda462 100644
--- a/daemon/device.c
+++ b/daemon/device.c
@@ -552,6 +552,11 @@ void device_data_input(struct usb_device *usbdev, unsigned char *buffer, int len
 
         // handle broken up transfers
         if(dev->pktlen) {
+                if((length + dev->pktlen) > DEV_PKTBUF_SIZE) {
+                        usbmuxd_log(LL_ERROR, "Incoming split packet is too large (%d so far), dropping!", length + dev->pktlen);
+                        dev->pktlen = 0;
+                        return;
+                }
                 memcpy(dev->pktbuf + dev->pktlen, buffer, length);
                 struct mux_header *mhdr = (struct mux_header *)dev->pktbuf;
                 if((length < USB_MRU) || (ntohl(mhdr->length) == length)) {