Commit 31fb4444 authored by Gerd Hoffmann's avatar Gerd Hoffmann
Browse files

usb-ccid: add check message size checks 



Check message size too when figuring whenever we should expect more data.
Fix debug message to show useful data, p->iov.size is fixed anyway if we
land there, print how much we got meanwhile instead.

Also check announced message size against actual message size.  That
is a more general fix for CVE-2017-5898 than commit "c7dfbf32 usb: ccid:
check ccid apdu length".

Signed-off-by: default avatarGerd Hoffmann <kraxel@redhat.com>
Reviewed-by: default avatarMarc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 1487250819-23764-4-git-send-email-kraxel@redhat.com
parent 7569c546

hw/usb/dev-smartcard-reader.c

+10 −3
Original line number Diff line number Diff line
@@ -1011,12 +1011,19 @@ static void ccid_handle_bulk_out(USBCCIDState *s, USBPacket *p) 
    }



    ccid_header = (CCID_Header *)s->bulk_out_data;

    if (p->iov.size == CCID_MAX_PACKET_SIZE) {

    if ((s->bulk_out_pos - 10 < ccid_header->dwLength) &&

        (p->iov.size == CCID_MAX_PACKET_SIZE)) {

        DPRINTF(s, D_VERBOSE,

            "usb-ccid: bulk_in: expecting more packets (%zd/%d)\n",

            p->iov.size, ccid_header->dwLength);

                "usb-ccid: bulk_in: expecting more packets (%d/%d)\n",

                s->bulk_out_pos - 10, ccid_header->dwLength);

        return;

    }

    if (s->bulk_out_pos - 10 != ccid_header->dwLength) {

        DPRINTF(s, 1,

                "usb-ccid: bulk_in: message size mismatch (got %d, expected %d)\n",

                s->bulk_out_pos - 10, ccid_header->dwLength);

        goto err;

    }



    DPRINTF(s, D_MORE_INFO, "%s %x %s\n", __func__,

            ccid_header->bMessageType,