linux.git/net/core/skbuff.c, branch v4.12

sock: reset sk_err when the error queue is empty

2017-06-05T00:01:53+00:00

Prior to f5f99309fa74 (sock: do not set sk_err in
sock_dequeue_err_skb), sk_err was reset to the error of
the skb on the head of the error queue.

Applications, most notably ping, are relying on this
behavior to reset sk_err for ICMP packets.

Set sk_err to the ICMP error when there is an ICMP packet
at the head of the error queue.

Fixes: f5f99309fa74 (sock: do not set sk_err in sock_dequeue_err_skb)
Reported-by: Cyril Hrubis 
Tested-by: Cyril Hrubis 
Signed-off-by: Soheil Hassas Yeganeh 
Signed-off-by: Eric Dumazet 
Signed-off-by: Willem de Bruijn 
Signed-off-by: David S. Miller

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

2017-05-02T23:40:27+00:00

Pull networking updates from David Millar:
 "Here are some highlights from the 2065 networking commits that
  happened this development cycle:

   1) XDP support for IXGBE (John Fastabend) and thunderx (Sunil Kowuri)

   2) Add a generic XDP driver, so that anyone can test XDP even if they
      lack a networking device whose driver has explicit XDP support
      (me).

   3) Sparc64 now has an eBPF JIT too (me)

   4) Add a BPF program testing framework via BPF_PROG_TEST_RUN (Alexei
      Starovoitov)

   5) Make netfitler network namespace teardown less expensive (Florian
      Westphal)

   6) Add symmetric hashing support to nft_hash (Laura Garcia Liebana)

   7) Implement NAPI and GRO in netvsc driver (Stephen Hemminger)

   8) Support TC flower offload statistics in mlxsw (Arkadi Sharshevsky)

   9) Multiqueue support in stmmac driver (Joao Pinto)

  10) Remove TCP timewait recycling, it never really could possibly work
      well in the real world and timestamp randomization really zaps any
      hint of usability this feature had (Soheil Hassas Yeganeh)

  11) Support level3 vs level4 ECMP route hashing in ipv4 (Nikolay
      Aleksandrov)

  12) Add socket busy poll support to epoll (Sridhar Samudrala)

  13) Netlink extended ACK support (Johannes Berg, Pablo Neira Ayuso,
      and several others)

  14) IPSEC hw offload infrastructure (Steffen Klassert)"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2065 commits)
  tipc: refactor function tipc_sk_recv_stream()
  tipc: refactor function tipc_sk_recvmsg()
  net: thunderx: Optimize page recycling for XDP
  net: thunderx: Support for XDP header adjustment
  net: thunderx: Add support for XDP_TX
  net: thunderx: Add support for XDP_DROP
  net: thunderx: Add basic XDP support
  net: thunderx: Cleanup receive buffer allocation
  net: thunderx: Optimize CQE_TX handling
  net: thunderx: Optimize RBDR descriptor handling
  net: thunderx: Support for page recycling
  ipx: call ipxitf_put() in ioctl error path
  net: sched: add helpers to handle extended actions
  qed*: Fix issues in the ptp filter config implementation.
  qede: Fix concurrency issue in PTP Tx path processing.
  stmmac: Add support for SIMATIC IOT2000 platform
  net: hns: fix ethtool_get_strings overflow in hns driver
  tcp: fix wraparound issue in tcp_lp
  bpf, arm64: fix jit branch offset related to ldimm64
  bpf, arm64: implement jiting of BPF_XADD
  ...

Merge branch 'work.splice' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2017-05-02T18:38:06+00:00

Pull splice updates from Al Viro:
 "These actually missed the last cycle; the branch itself is from last
  December"

* 'work.splice' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  make nr_pages calculation in default_file_splice_read() a bit less ugly
  splice/tee/vmsplice: validate flags
  splice_pipe_desc: kill ->flags
  remove spd_release_page()

net: adjust skb->truesize in ___pskb_trim()

2017-04-28T20:06:47+00:00

Andrey found a way to trigger the WARN_ON_ONCE(delta < len) in
skb_try_coalesce() using syzkaller and a filter attached to a TCP
socket.

As we did recently in commit 158f323b9868 ("net: adjust skb->truesize in
pskb_expand_head()") we can adjust skb->truesize from ___pskb_trim(),
via a call to skb_condense().

If all frags were freed, then skb->truesize can be recomputed.

This call can be done if skb is not yet owned, or destructor is
sock_edemux().

Signed-off-by: Eric Dumazet 
Reported-by: Andrey Konovalov 
Cc: Willem de Bruijn 
Signed-off-by: David S. Miller

gso: Validate assumption of frag_list segementation

2017-04-21T17:30:29+00:00

Commit 07b26c9454a2 ("gso: Support partial splitting at the frag_list
pointer") assumes that all SKBs in a frag_list (except maybe the last
one) contain the same amount of GSO payload.

This assumption is not always correct, resulting in the following
warning message in the log:
    skb_segment: too many frags

For example, mlx5 driver in Striding RQ mode creates some RX SKBs with
one frag, and some with 2 frags.
After GRO, the frag_list SKBs end up having different amounts of payload.
If this frag_list SKB is then forwarded, the aforementioned assumption
is violated.

Validate the assumption, and fall back to software GSO if it not true.

Change-Id: Ia03983f4a47b6534dd987d7a2aad96d54d46d212
Fixes: 07b26c9454a2 ("gso: Support partial splitting at the frag_list pointer")
Signed-off-by: Ilan Tayari 
Signed-off-by: Ilya Lesokhin 
Signed-off-by: David S. Miller

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

2017-04-20T14:35:33+00:00

A function in kernel/bpf/syscall.c which got a bug fix in 'net'
was moved to kernel/bpf/verifier.c in 'net-next'.

Signed-off-by: David S. Miller

gso: Validate assumption of frag_list segementation

2017-04-17T19:31:29+00:00

Commit 07b26c9454a2 ("gso: Support partial splitting at the frag_list
pointer") assumes that all SKBs in a frag_list (except maybe the last
one) contain the same amount of GSO payload.

This assumption is not always correct, resulting in the following
warning message in the log:
    skb_segment: too many frags

For example, mlx5 driver in Striding RQ mode creates some RX SKBs with
one frag, and some with 2 frags.
After GRO, the frag_list SKBs end up having different amounts of payload.
If this frag_list SKB is then forwarded, the aforementioned assumption
is violated.

Validate the assumption, and fall back to software GSO if it not true.

Fixes: 07b26c9454a2 ("gso: Support partial splitting at the frag_list pointer")
Signed-off-by: Ilan Tayari 
Signed-off-by: Ilya Lesokhin 
Signed-off-by: David S. Miller

net-timestamp: avoid use-after-free in ip_recv_error

2017-04-17T16:59:22+00:00

Syzkaller reported a use-after-free in ip_recv_error at line

    info->ipi_ifindex = skb->dev->ifindex;

This function is called on dequeue from the error queue, at which
point the device pointer may no longer be valid.

Save ifindex on enqueue in __skb_complete_tx_timestamp, when the
pointer is valid or NULL. Store it in temporary storage skb->cb.

It is safe to reference skb->dev here, as called from device drivers
or dev_queue_xmit. The exception is when called from tcp_ack_tstamp;
in that case it is NULL and ifindex is set to 0 (invalid).

Do not return a pktinfo cmsg if ifindex is 0. This maintains the
current behavior of not returning a cmsg if skb->dev was NULL.

On dequeue, the ipv4 path will cast from sock_exterr_skb to
in_pktinfo. Both have ifindex as their first element, so no explicit
conversion is needed. This is by design, introduced in commit
0b922b7a829c ("net: original ingress device index in PKTINFO"). For
ipv6 ip6_datagram_support_cmsg converts to in6_pktinfo.

Fixes: 829ae9d61165 ("net-timestamp: allow reading recv cmsg on errqueue with origin tstamp")
Reported-by: Andrey Konovalov 
Signed-off-by: Willem de Bruijn 
Signed-off-by: David S. Miller

gso: Support frag_list splitting with head_frag

2017-04-12T17:53:35+00:00

A driver may use build_skb() for received packets.
These SKBs then have a head_frag.

Since commit d7e8883cfcf4 ("net: make GRO aware of
skb->head_frag"), GRO may build frag_list SKBs out of
head_frag received SKBs.
In such a case, the chained SKBs end up with a head_frag.

Commit 07b26c9454a2 ("gso: Support partial splitting at
the frag_list pointer") adds partial segmentation of frag_list
SKB chains into individual SKBs.
However, this is not done if the chained SKBs have any
linear part, because the device may not be able to DMA
the private linear buffer.

A chained frag_list SKB with head_frag is wrongfully
detected in this case as having a private linear part
and thus falls back to software GSO, while in fact the
linear part is backed by a DMA page just like any other frag.

This causes low performance when forwarding those packets
that were built with build_skb()

Allow partial segmentation at the frag_list pointer for
chained SKBs with head_frag.

Note that such SKBs can only be created by GRO, when applied
to received packets with head_frag.
Also note that this change only affects the data path that
performs the partial segmentation at frag_list pointer, and
not any of the other more common data paths.

Signed-off-by: Ilan Tayari 
Signed-off-by: David S. Miller

tcp: mark skbs with SCM_TIMESTAMPING_OPT_STATS

2017-03-22T01:44:17+00:00

SOF_TIMESTAMPING_OPT_STATS can be enabled and disabled
while packets are collected on the error queue.
So, checking SOF_TIMESTAMPING_OPT_STATS in sk->sk_tsflags
is not enough to safely assume that the skb contains
OPT_STATS data.

Add a bit in sock_exterr_skb to indicate whether the
skb contains opt_stats data.

Fixes: 1c885808e456 ("tcp: SOF_TIMESTAMPING_OPT_STATS option for SO_TIMESTAMPING")
Reported-by: JongHwan Kim 
Signed-off-by: Soheil Hassas Yeganeh 
Signed-off-by: Eric Dumazet 
Signed-off-by: Willem de Bruijn 
Signed-off-by: David S. Miller