debian/patches/old/0001-net-pcnet-add-check-to-validate-receive-data-size-CV.patch

   1 From 6314c83ae14ee32835668e38bb55f4b93b800736 Mon Sep 17 00:00:00 2001
   2 From: Prasad J Pandit <pjp@fedoraproject.org>
   3 Date: Mon, 30 Nov 2015 15:38:22 +0800
   4 Subject: [PATCH 1/2] net: pcnet: add check to validate receive data
   5  size(CVE-2015-7504)
   6
   7 In loopback mode, pcnet_receive routine appends CRC code to the
   8 receive buffer. If the data size given is same as the buffer size,
   9 the appended CRC code overwrites 4 bytes after s->buffer. Added a
  10 check to avoid that.
  11
  12 Reported by: Qinghao Tang <luodalongde@gmail.com>
  13 Cc: qemu-stable@nongnu.org
  14 Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
  15 Signed-off-by: Jason Wang <jasowang@redhat.com>
  16 ---
  17  hw/net/pcnet.c | 8 +++++---
  18  1 file changed, 5 insertions(+), 3 deletions(-)
  19
  20 diff --git a/hw/net/pcnet.c b/hw/net/pcnet.c
  21 index 0eb3cc4..309c40b 100644
  22 --- a/hw/net/pcnet.c
  23 +++ b/hw/net/pcnet.c
  24 @@ -1084,7 +1084,7 @@ ssize_t pcnet_receive(NetClientState *nc, const uint8_t *buf, size_t size_)
  25                  uint32_t fcs = ~0;
  26                  uint8_t *p = src;
  27
  28 -                while (p != &src[size-4])
  29 +                while (p != &src[size])
  30                      CRC(fcs, *p++);
  31                  crc_err = (*(uint32_t *)p != htonl(fcs));
  32              }
  33 @@ -1233,8 +1233,10 @@ static void pcnet_transmit(PCNetState *s)
  34          bcnt = 4096 - GET_FIELD(tmd.length, TMDL, BCNT);
  35
  36          /* if multi-tmd packet outsizes s->buffer then skip it silently.
  37 -           Note: this is not what real hw does */
  38 -        if (s->xmit_pos + bcnt > sizeof(s->buffer)) {
  39 +         * Note: this is not what real hw does.
  40 +         * Last four bytes of s->buffer are used to store CRC FCS code.
  41 +         */
  42 +        if (s->xmit_pos + bcnt > sizeof(s->buffer) - 4) {
  43              s->xmit_pos = -1;
  44              goto txdone;
  45          }
  46 --
  47 2.1.4
  48