linux-stable.git/net/ipv4/ip_output.c, branch linux-4.16.y

net: test tailroom before appending to linear skb

2018-05-25T14:46:01+00:00

[ Upstream commit 113f99c3358564a0647d444c2ae34e8b1abfd5b9 ]

Device features may change during transmission. In particular with
corking, a device may toggle scatter-gather in between allocating
and writing to an skb.

Do not unconditionally assume that !NETIF_F_SG at write time implies
that the same held at alloc time and thus the skb has sufficient
tailroom.

This issue predates git history.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Eric Dumazet 
Signed-off-by: Willem de Bruijn 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: rename skb_gso_validate_mtu -> skb_gso_validate_network_len

2018-03-04T22:49:17+00:00

If you take a GSO skb, and split it into packets, will the network
length (L3 headers + L4 headers + payload) of those packets be small
enough to fit within a given MTU?

skb_gso_validate_mtu gives you the answer to that question. However,
we recently added to add a way to validate the MAC length of a split GSO
skb (L2+L3+L4+payload), and the names get confusing, so rename
skb_gso_validate_mtu to skb_gso_validate_network_len

Signed-off-by: Daniel Axtens 
Reviewed-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller

udp: remove unreachable ufo branches

2017-08-22T21:27:18+00:00

Remove two references to ufo in the udp send path that are no longer
reachable now that ufo has been removed.

Commit 85f1bd9a7b5a ("udp: consistently apply ufo or fragmentation")
is a fix to ufo. It is safe to revert what remains of it.

Also, no skb can enter ip_append_page with skb_is_gso true now that
skb_shinfo(skb)->gso_type is no longer set in ip_append_page/_data.

Signed-off-by: Willem de Bruijn 
Signed-off-by: David S. Miller

ip/options: explicitly provide net ns to __ip_options_echo()

2017-08-07T03:51:12+00:00

__ip_options_echo() uses the current network namespace, and
currently retrives it via skb->dst->dev.

This commit adds an explicit 'net' argument to __ip_options_echo()
and update all the call sites to provide it, usually via a simpler
sock_net().

After this change, __ip_options_echo() no more needs to access
skb->dst and we can drop a couple of hack to preserve such
info in the rx path.

Signed-off-by: Paolo Abeni 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2017-07-21T02:38:43+00:00

inet: Stop generating UFO packets.

2017-07-17T16:52:58+00:00

Signed-off-by: David S. Miller

ipv4: ip_do_fragment: fix headroom tests

2017-07-15T21:38:31+00:00

Some time ago David Woodhouse reported skb_under_panic
when we try to push ethernet header to fragmented ipv6 skbs.
It was fixed for ipv6 by Florian Westphal in
commit 1d325d217c7f ("ipv6: ip6_fragment: fix headroom tests and skb leak")

However similar problem still exist in ipv4.

It does not trigger skb_under_panic due paranoid check
in ip_finish_output2, however according to Alexey Kuznetsov
current state is abnormal and ip_fragment should be fixed too.

Signed-off-by: Vasily Averin 
Signed-off-by: David S. Miller

net: reflect mark on tcp syn ack packets

2017-07-04T08:46:10+00:00

SYN-ACK responses on a server in response to a SYN from a client
did not get the injected skb mark that was tagged on the SYN packet.

Fixes: 84f39b08d786 ("net: support marking accepting TCP sockets")
Reviewed-by: Lorenzo Colitti 
Signed-off-by: Jamal Hadi Salim 
Signed-off-by: David S. Miller

net: convert sock.sk_wmem_alloc from atomic_t to refcount_t

2017-07-01T14:39:08+00:00

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova 
Signed-off-by: Hans Liljestrand 
Signed-off-by: Kees Cook 
Signed-off-by: David Windsor 
Signed-off-by: David S. Miller

net: account for current skb length when deciding about UFO

2017-06-23T17:29:38+00:00

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: e89e9cf539a2 ("[IPv4/IPv6]: UFO Scatter-gather approach")
Fixes: e4c5e13aa45c ("ipv6: Should use consistent conditional judgement for
	ip6 fragment between __ip6_append_data and ip6_finish_output")
Signed-off-by: Michal Kubecek 
Acked-by: Vlad Yasevich 
Signed-off-by: David S. Miller