1. 08 Aug, 2017 3 commits
    • Alexey Kodanev's avatar
      udp: avoid ufo handling on IP payload compression packets · 0de6ee9d
      Alexey Kodanev authored
      commit c146066a ("ipv4: Don't use ufo handling on later transformed
      packets") and commit f89c56ce ("ipv6: Don't use ufo handling on
      later transformed packets") added a check that 'rt->dst.header_len' isn't
      zero in order to skip UFO, but it doesn't include IPcomp in transport mode
      where it equals zero.
      
      Packets, after payload compression, may not require further fragmentation,
      and if original length exceeds MTU, later compressed packets will be
      transmitted incorrectly. This can be reproduced with LTP udp_ipsec.sh test
      on veth device with enabled UFO, MTU is 1500 and UDP payload is 2000:
      
      * IPv4 case, offset is wrong + unnecessary fragmentation
          udp_ipsec.sh -p comp -m transport -s 2000 &
          tcpdump -ni ltp_ns_veth2
          ...
          IP (tos 0x0, ttl 64, id 45203, offset 0, flags [+],
            proto Compressed IP (108), length 49)
            10.0.0.2 > 10.0.0.1: IPComp(cpi=0x1000)
          IP (tos 0x0, ttl 64, id 45203, offset 1480, flags [none],
            proto UDP (17), length 21) 10.0.0.2 > 10.0.0.1: ip-proto-17
      
      * IPv6 case, sending small fragments
          udp_ipsec.sh -6 -p comp -m transport -s 2000 &
          tcpdump -ni ltp_ns_veth2
          ...
          IP6 (flowlabel 0x6b9ba, hlim 64, next-header Compressed IP (108)
            payload length: 37) fd00::2 > fd00::1: IPComp(cpi=0x1000)
          IP6 (flowlabel 0x6b9ba, hlim 64, next-header Compressed IP (108)
            payload length: 21) fd00::2 > fd00::1: IPComp(cpi=0x1000)
      
      Fix it by checking 'rt->dst.xfrm' pointer to 'xfrm_state' struct, skip UFO
      if xfrm is set. So the new check will include both cases: IPcomp and IPsec.
      
      Fixes: c146066a ("ipv4: Don't use ufo handling on later transformed packets")
      Fixes: f89c56ce ("ipv6: Don't use ufo handling on later transformed packets")
      Signed-off-by: default avatarAlexey Kodanev <alexey.kodanev@oracle.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      
      CVE-2017-1000112
      
      (cherry-picked from commit 4b3b45ed)
      Signed-off-by: default avatarStefan Bader <stefan.bader@canonical.com>
      0de6ee9d
    • Jakub Sitnicki's avatar
      ipv6: Don't use ufo handling on later transformed packets · d10b5e3d
      Jakub Sitnicki authored
      Similar to commit c146066a ("ipv4: Don't use ufo handling on later
      transformed packets"), don't perform UFO on packets that will be IPsec
      transformed. To detect it we rely on the fact that headerlen in
      dst_entry is non-zero only for transformation bundles (xfrm_dst
      objects).
      
      Unwanted segmentation can be observed with a NETIF_F_UFO capable device,
      such as a dummy device:
      
        DEV=dum0 LEN=1493
      
        ip li add $DEV type dummy
        ip addr add fc00::1/64 dev $DEV nodad
        ip link set $DEV up
        ip xfrm policy add dir out src fc00::1 dst fc00::2 \
           tmpl src fc00::1 dst fc00::2 proto esp spi 1
        ip xfrm state add src fc00::1 dst fc00::2 \
           proto esp spi 1 enc 'aes' 0x0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b
      
        tcpdump -n -nn -i $DEV -t &
        socat /dev/zero,readbytes=$LEN udp6:[fc00::2]:$LEN
      
      tcpdump output before:
      
        IP6 fc00::1 > fc00::2: frag (0|1448) ESP(spi=0x00000001,seq=0x1), length 1448
        IP6 fc00::1 > fc00::2: frag (1448|48)
        IP6 fc00::1 > fc00::2: ESP(spi=0x00000001,seq=0x2), length 88
      
      ... and after:
      
        IP6 fc00::1 > fc00::2: frag (0|1448) ESP(spi=0x00000001,seq=0x1), length 1448
        IP6 fc00::1 > fc00::2: frag (1448|80)
      
      Fixes: e89e9cf5 ("[IPv4/IPv6]: UFO Scatter-gather approach")
      Signed-off-by: default avatarJakub Sitnicki <jkbs@redhat.com>
      Acked-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      
      CVE-2017-1000112
      
      (cherry-picked from commit f89c56ce)
      Signed-off-by: default avatarStefan Bader <stefan.bader@canonical.com>
      d10b5e3d
    • zheng li's avatar
      ipv4: Should use consistent conditional judgement for ip fragment in... · 0ca67031
      zheng li authored
      ipv4: Should use consistent conditional judgement for ip fragment in __ip_append_data and ip_finish_output
      
      There is an inconsistent conditional judgement in __ip_append_data and
      ip_finish_output functions, the variable length in __ip_append_data just
      include the length of application's payload and udp header, don't include
      the length of ip header, but in ip_finish_output use
      (skb->len > ip_skb_dst_mtu(skb)) as judgement, and skb->len include the
      length of ip header.
      
      That causes some particular application's udp payload whose length is
      between (MTU - IP Header) and MTU were fragmented by ip_fragment even
      though the rst->dev support UFO feature.
      
      Add the length of ip header to length in __ip_append_data to keep
      consistent conditional judgement as ip_finish_output for ip fragment.
      Signed-off-by: default avatarZheng Li <james.z.li@ericsson.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      
      CVE-2017-1000112
      
      (cherry-picked from commit 0a28cfd5)
      Signed-off-by: default avatarStefan Bader <stefan.bader@canonical.com>
      0ca67031
  2. 07 Aug, 2017 2 commits
  3. 31 Jul, 2017 3 commits
  4. 20 Jul, 2017 1 commit
  5. 19 Jul, 2017 31 commits