debian/patches/extra/CVE-2016-7908-net-mcf-limit-buffer-descriptor-count.patch

   1 From 94087c0cbe014b4a60d96930d7cb43d54a05c701 Mon Sep 17 00:00:00 2001
   2 From: Prasad J Pandit <pjp@fedoraproject.org>
   3 Date: Thu, 22 Sep 2016 16:02:37 +0530
   4 Subject: [PATCH 6/7] net: mcf: limit buffer descriptor count
   5
   6 ColdFire Fast Ethernet Controller uses buffer descriptors to manage
   7 data flow to/fro receive & transmit queues. While transmitting
   8 packets, it could continue to read buffer descriptors if a buffer
   9 descriptor has length of zero and has crafted values in bd.flags.
  10 Set upper limit to number of buffer descriptors.
  11
  12 Reported-by: Li Qiang <liqiang6-s@360.cn>
  13 Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
  14 Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
  15 Signed-off-by: Jason Wang <jasowang@redhat.com>
  16 ---
  17  hw/net/mcf_fec.c | 5 +++--
  18  1 file changed, 3 insertions(+), 2 deletions(-)
  19
  20 diff --git a/hw/net/mcf_fec.c b/hw/net/mcf_fec.c
  21 index 0ee8ad9..d31fea1 100644
  22 --- a/hw/net/mcf_fec.c
  23 +++ b/hw/net/mcf_fec.c
  24 @@ -23,6 +23,7 @@ do { printf("mcf_fec: " fmt , ## __VA_ARGS__); } while (0)
  25  #define DPRINTF(fmt, ...) do {} while(0)
  26  #endif
  27
  28 +#define FEC_MAX_DESC 1024
  29  #define FEC_MAX_FRAME_SIZE 2032
  30
  31  typedef struct {
  32 @@ -149,7 +150,7 @@ static void mcf_fec_do_tx(mcf_fec_state *s)
  33      uint32_t addr;
  34      mcf_fec_bd bd;
  35      int frame_size;
  36 -    int len;
  37 +    int len, descnt = 0;
  38      uint8_t frame[FEC_MAX_FRAME_SIZE];
  39      uint8_t *ptr;
  40
  41 @@ -157,7 +158,7 @@ static void mcf_fec_do_tx(mcf_fec_state *s)
  42      ptr = frame;
  43      frame_size = 0;
  44      addr = s->tx_descriptor;
  45 -    while (1) {
  46 +    while (descnt++ < FEC_MAX_DESC) {
  47          mcf_fec_read_bd(&bd, addr);
  48          DPRINTF("tx_bd %x flags %04x len %d data %08x\n",
  49                  addr, bd.flags, bd.length, bd.data);
  50 --
  51 2.1.4
  52