From fe3c546c5ff2a6210f9a4d8561cc64051ca8603e Mon Sep 17 00:00:00 2001 From: Prasad J Pandit Date: Wed, 17 Feb 2016 00:23:41 +0530 Subject: [PATCH] usb: check RNDIS buffer offsets & length When processing remote NDIS control message packets, the USB Net device emulator uses a fixed length(4096) data buffer. The incoming informationBufferOffset & Length combination could overflow and cross that range. Check control message buffer offsets and length to avoid it. Reported-by: Qinghao Tang Signed-off-by: Prasad J Pandit Message-id: 1455648821-17340-3-git-send-email-ppandit@redhat.com Signed-off-by: Gerd Hoffmann --- hw/usb/dev-network.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/hw/usb/dev-network.c b/hw/usb/dev-network.c index 5dc4538..c6abd38 100644 --- a/hw/usb/dev-network.c +++ b/hw/usb/dev-network.c @@ -916,8 +916,9 @@ static int rndis_query_response(USBNetState *s, bufoffs = le32_to_cpu(buf->InformationBufferOffset) + 8; buflen = le32_to_cpu(buf->InformationBufferLength); - if (bufoffs + buflen > length) + if (buflen > length || bufoffs >= length || bufoffs + buflen > length) { return USB_RET_STALL; + } infobuflen = ndis_query(s, le32_to_cpu(buf->OID), bufoffs + (uint8_t *) buf, buflen, infobuf, @@ -962,8 +963,9 @@ static int rndis_set_response(USBNetState *s, bufoffs = le32_to_cpu(buf->InformationBufferOffset) + 8; buflen = le32_to_cpu(buf->InformationBufferLength); - if (bufoffs + buflen > length) + if (buflen > length || bufoffs >= length || bufoffs + buflen > length) { return USB_RET_STALL; + } ret = ndis_set(s, le32_to_cpu(buf->OID), bufoffs + (uint8_t *) buf, buflen); @@ -1213,8 +1215,9 @@ static void usb_net_handle_dataout(USBNetState *s, USBPacket *p) if (le32_to_cpu(msg->MessageType) == RNDIS_PACKET_MSG) { uint32_t offs = 8 + le32_to_cpu(msg->DataOffset); uint32_t size = le32_to_cpu(msg->DataLength); - if (offs + size <= len) + if (offs < len && size < len && offs + size <= len) { qemu_send_packet(qemu_get_queue(s->nic), s->out_buf + offs, size); + } } s->out_ptr -= len; memmove(s->out_buf, &s->out_buf[len], s->out_ptr); -- 2.7.4