linux-toradex.git/net, branch v3.12.2

SUNRPC: Avoid deep recursion in rpc_release_client

2013-11-29T19:28:09+00:00

commit d07ba8422f1e58be94cc98a1f475946dc1b89f1b upstream.

In cases where an rpc client has a parent hierarchy, then
rpc_free_client may end up calling rpc_release_client() on the
parent, thus recursing back into rpc_free_client. If the hierarchy
is deep enough, then we can get into situations where the stack
simply overflows.

The fix is to have rpc_release_client() loop so that it can take
care of the parent rpc client hierarchy without needing to
recurse.

Reported-by: Jeff Layton 
Reported-by: Weston Andros Adamson 
Reported-by: Bruce Fields 
Link: http://lkml.kernel.org/r/2C73011F-0939-434C-9E4D-13A1EB1403D7@netapp.com
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

SUNRPC: Fix a data corruption issue when retransmitting RPC calls

2013-11-29T19:28:09+00:00

commit a6b31d18b02ff9d7915c5898c9b5ca41a798cd73 upstream.

The following scenario can cause silent data corruption when doing
NFS writes. It has mainly been observed when doing database writes
using O_DIRECT.

1) The RPC client uses sendpage() to do zero-copy of the page data.
2) Due to networking issues, the reply from the server is delayed,
   and so the RPC client times out.

3) The client issues a second sendpage of the page data as part of
   an RPC call retransmission.

4) The reply to the first transmission arrives from the server
   _before_ the client hardware has emptied the TCP socket send
   buffer.
5) After processing the reply, the RPC state machine rules that
   the call to be done, and triggers the completion callbacks.
6) The application notices the RPC call is done, and reuses the
   pages to store something else (e.g. a new write).

7) The client NIC drains the TCP socket send buffer. Since the
   page data has now changed, it reads a corrupted version of the
   initial RPC call, and puts it on the wire.

This patch fixes the problem in the following manner:

The ordering guarantees of TCP ensure that when the server sends a
reply, then we know that the _first_ transmission has completed. Using
zero-copy in that situation is therefore safe.
If a time out occurs, we then send the retransmission using sendmsg()
(i.e. no zero-copy), We then know that the socket contains a full copy of
the data, and so it will retransmit a faithful reproduction even if the
RPC call completes, and the application reuses the O_DIRECT buffer in
the meantime.

Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

SUNRPC: gss_alloc_msg - choose _either_ a v0 message or a v1 message

2013-11-29T19:28:09+00:00

commit 5fccc5b52ee07d07a74ce53c6f174bff81e26a16 upstream.

Add the missing 'break' to ensure that we don't corrupt a legacy 'v0' type
message by appending the 'v1'.

Cc: Bruce Fields 
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

ipv6: ip6_dst_check needs to check for expired dst_entries

2013-11-20T20:37:36+00:00

[ Upstream commit e3bc10bd95d7fcc3f2ac690c6ff22833ea6781d6 ]

On receiving a packet too big icmp error we check if our current cached
dst_entry in the socket is still valid. This validation check did not
care about the expiration of the (cached) route.

The error path I traced down:
The socket receives a packet too big mtu notification. It still has a
valid dst_entry and thus issues the ip6_rt_pmtu_update on this dst_entry,
setting RTF_EXPIRE and updates the dst.expiration value (which could
fail because of not up-to-date expiration values, see previous patch).

In some seldom cases we race with a) the ip6_fib gc or b) another routing
lookup which would result in a recreation of the cached rt6_info from its
parent non-cached rt6_info. While copying the rt6_info we reinitialize the
metrics store by copying it over from the parent thus invalidating the
just installed pmtu update (both dsts use the same key to the inetpeer
storage). The dst_entry with the just invalidated metrics data would
just get its RTF_EXPIRES flag cleared and would continue to stay valid
for the socket.

We should have not issued the pmtu update on the already expired dst_entry
in the first placed. By checking the expiration on the dst entry and
doing a relookup in case it is out of date we close the race because
we would install a new rt6_info into the fib before we issue the pmtu
update, thus closing this race.

Not reliably updating the dst.expire value was fixed by the patch "ipv6:
reset dst.expires value when clearing expire flag".

Reported-by: Steinar H. Gunderson 
Reported-by: Valentijn Sessink 
Cc: YOSHIFUJI Hideaki 
Signed-off-by: Hannes Frederic Sowa 
Reviewed-by: Eric Dumazet 
Tested-by: Valentijn Sessink 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: do not rearm RTO when future data are sacked

2013-11-20T20:37:36+00:00

[ Upstream commit 2f715c1dde6e1760f3101358dc26f8c9489be0bf ]

Patch ed08495c3 "tcp: use RTT from SACK for RTO" always re-arms RTO upon
obtaining a RTT sample from newly sacked data.

But technically RTO should only be re-armed when the data sent before
the last (re)transmission of write queue head are (s)acked. Otherwise
the RTO may continue to extend during loss recovery on data sent
in the future.

Note that RTTs from ACK or timestamps do not have this problem, as the RTT
source must be from data sent before.

The new RTO re-arm policy is
1) Always re-arm RTO if SND.UNA is advanced
2) Re-arm RTO if sack RTT is available, provided the sacked data was
   sent before the last time write_queue_head was sent.

Signed-off-by: Larry Brakmo 
Signed-off-by: Yuchung Cheng 
Acked-by: Neal Cardwell 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: only take RTT from timestamps if new data is acked

2013-11-20T20:37:36+00:00

[ Upstream commit 2909d874f34eae157aecab0af27c6dc4a1751f8f ]

Patch ed08495c3 "tcp: use RTT from SACK for RTO" has a bug that
it does not check if the ACK acknowledge new data before taking
the RTT sample from TCP timestamps. This patch adds the check
back as required by the RFC.

Signed-off-by: Yuchung Cheng 
Acked-by: Neal Cardwell 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: fix SYNACK RTT estimation in Fast Open

2013-11-20T20:37:36+00:00

[ Upstream commit bc15afa39ecc16f01c3389d15d8f6015a427fe85 ]

tp->lsndtime may not always be the SYNACK timestamp if a passive
Fast Open socket sends data before handshake completes. And if the
remote acknowledges both the data and the SYNACK, the RTT sample
is already taken in tcp_ack(), so no need to call
tcp_update_ack_rtt() in tcp_synack_rtt_meas() aagain.

Signed-off-by: Yuchung Cheng 
Acked-by: Neal Cardwell 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: gso: fix truesize tracking

2013-11-20T20:37:36+00:00

[ Upstream commit 0d08c42cf9a71530fef5ebcfe368f38f2dd0476f ]

commit 6ff50cd55545 ("tcp: gso: do not generate out of order packets")
had an heuristic that can trigger a warning in skb_try_coalesce(),
because skb->truesize of the gso segments were exactly set to mss.

This breaks the requirement that

skb->truesize >= skb->len + truesizeof(struct sk_buff);

It can trivially be reproduced by :

ifconfig lo mtu 1500
ethtool -K lo tso off
netperf

As the skbs are looped into the TCP networking stack, skb_try_coalesce()
warns us of these skb under-estimating their truesize.

Signed-off-by: Eric Dumazet 
Reported-by: Alexei Starovoitov 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: flow_dissector: fail on evil iph->ihl

2013-11-20T20:37:36+00:00

[ Upstream commit 6f092343855a71e03b8d209815d8c45bf3a27fcd ]

We don't validate iph->ihl which may lead a dead loop if we meet a IPIP
skb whose iph->ihl is zero. Fix this by failing immediately when iph->ihl
is evil (less than 5).

This issue were introduced by commit ec5efe7946280d1e84603389a1030ccec0a767ae
(rps: support IPIP encapsulation).

Signed-off-by: Jason Wang 
Cc: Eric Dumazet 
Cc: Petr Matousek 
Cc: Michael S. Tsirkin 
Cc: Daniel Borkmann 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: sctp: do not trigger BUG_ON in sctp_cmd_delete_tcb

2013-11-20T20:37:35+00:00

[ Upstream commit 7926c1d5be0b7cbe5b8d5c788d7d39237e7b212c ]

Introduced in f9e42b853523 ("net: sctp: sideeffect: throw BUG if
primary_path is NULL"), we intended to find a buggy assoc that's
part of the assoc hash table with a primary_path that is NULL.
However, we better remove the BUG_ON for now and find a more
suitable place to assert for these things as Mark reports that
this also triggers the bug when duplication cookie processing
happens, and the assoc is not part of the hash table (so all
good in this case). Such a situation can for example easily be
reproduced by:

  tc qdisc add dev eth0 root handle 1: prio bands 2 priomap 1 1 1 1 1 1
  tc qdisc add dev eth0 parent 1:2 handle 20: netem loss 20%
  tc filter add dev eth0 protocol ip parent 1: prio 2 u32 match ip \
            protocol 132 0xff match u8 0x0b 0xff at 32 flowid 1:2

This drops 20% of COOKIE-ACK packets. After some follow-up
discussion with Vlad we came to the conclusion that for now we
should still better remove this BUG_ON() assertion, and come up
with two follow-ups later on, that is, i) find a more suitable
place for this assertion, and possibly ii) have a special
allocator/initializer for such kind of temporary assocs.

Reported-by: Mark Thomas 
Signed-off-by: Vlad Yasevich 
Signed-off-by: Daniel Borkmann 
Acked-by: Neil Horman 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman