Skip to content

L
linux
Switch branch/tag
  1. 10 Aug, 2017 1 commit
  3. 08 Aug, 2017 7 commits
    • Stefan Bader's avatar
      UBUNTU: Ubuntu-4.4.0-91.114 · 474ab8f0
      Stefan Bader authored 
      Signed-off-by: default avatarStefan Bader <stefan.bader@canonical.com>
      474ab8f0
    • Willem de Bruijn's avatar
      udp: consistently apply ufo or fragmentation · 840d468d
      Willem de Bruijn authored 
      When iteratively building a UDP datagram with MSG_MORE and that
datagram exceeds MTU, consistently choose UFO or fragmentation.

Once skb_is_gso, always apply ufo. Conversely, once a datagram is
split across multiple skbs, do not consider ufo.

Sendpage already maintains the first invariant, only add the second.
IPv6 does not have a sendpage implementation to modify.

Fixes: e89e9cf5 ("[IPv4/IPv6]: UFO Scatter-gather approach")
Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Signed-off-by: default avatarWillem de Bruijn <willemb@google.com>

CVE-2017-1000112

(backported from email submission)
Signed-off-by: default avatarStefan Bader <stefan.bader@canonical.com>
      840d468d
    • Michal Kubeček's avatar
      net: account for current skb length when deciding about UFO · 3b4e2b1d
      Michal Kubeček authored 
      Our customer encountered stuck NFS writes for blocks starting at specific
offsets w.r.t. page boundary caused by networking stack sending packets via
UFO enabled device with wrong checksum. The problem can be reproduced by
composing a long UDP datagram from multiple parts using MSG_MORE flag:

  sendto(sd, buff, 1000, MSG_MORE, ...);
  sendto(sd, buff, 1000, MSG_MORE, ...);
  sendto(sd, buff, 3000, 0, ...);

Assume this packet is to be routed via a device with MTU 1500 and
NETIF_F_UFO enabled. When second sendto() gets into __ip_append_data(),
this condition is tested (among others) to decide whether to call
ip_ufo_append_data():

  ((length + fragheaderlen) > mtu) || (skb && skb_is_gso(skb))

At the moment, we already have skb with 1028 bytes of data which is not
marked for GSO so that the test is false (fragheaderlen is usually 20).
Thus we append second 1000 bytes to this skb without invoking UFO. Third
sendto(), however, has sufficient length to trigger the UFO path so that we
end up with non-UFO skb followed by a UFO one. Later on, udp_send_skb()
uses udp_csum() to calculate the checksum but that assumes all fragments
have correct checksum in skb->csum which is not true for UFO fragments.

When checking against MTU, we need to add skb->len to length of new segment
if we already have a partially filled skb and fragheaderlen only if there
isn't one.

In the IPv6 case, skb can only be null if this is the first segment so that
we have to use headersize (length of the first IPv6 header) rather than
fragheaderlen (length of IPv6 header of further fragments) for skb == NULL.

Fixes: e89e9cf5 ("[IPv4/IPv6]: UFO Scatter-gather approach")
Fixes: e4c5e13a ("ipv6: Should use consistent conditional judgement for
	ip6 fragment between __ip6_append_data and ip6_finish_output")
Signed-off-by: default avatarMichal Kubecek <mkubecek@suse.cz>
Acked-by: default avatarVlad Yasevich <vyasevic@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>

CVE-2017-1000112
Signed-off-by: default avatarStefan Bader <stefan.bader@canonical.com>
      3b4e2b1d
    • Zheng Li's avatar
      ipv6: Should use consistent conditional judgement for ip6 fragment between... · 74b6bea3
      Zheng Li authored 
      ipv6: Should use consistent conditional judgement for ip6 fragment between __ip6_append_data and ip6_finish_output

There is an inconsistent conditional judgement between __ip6_append_data
and ip6_finish_output functions, the variable length in __ip6_append_data
just include the length of application's payload and udp6 header, don't
include the length of ipv6 header, but in ip6_finish_output use
(skb->len > ip6_skb_dst_mtu(skb)) as judgement, and skb->len include the
length of ipv6 header.

That causes some particular application's udp6 payloads whose length are
between (MTU - IPv6 Header) and MTU were fragmented by ip6_fragment even
though the rst->dev support UFO feature.

Add the length of ipv6 header to length in __ip6_append_data to keep
consistent conditional judgement as ip6_finish_output for ip6 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 e4c5e13a)
Signed-off-by: default avatarStefan Bader <stefan.bader@canonical.com>
      74b6bea3
    • 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
  5. 07 Aug, 2017 2 commits
  7. 31 Jul, 2017 3 commits
  9. 20 Jul, 2017 1 commit
  11. 19 Jul, 2017 26 commits
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7