linux-stable.git/net/core, branch v3.4.12

net: Statically initialize init_net.dev_base_head

2012-10-02T17:30:35+00:00

commit 734b65417b24d6eea3e3d7457e1f11493890ee1d upstream.

This change eliminates an initialization-order hazard most
recently seen when netprio_cgroup is built into the kernel.

With thanks to Eric Dumazet for catching a bug.

Signed-off-by: Mark Rustad 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

af_packet: don't emit packet on orig fanout group

2012-10-02T17:29:37+00:00

[ Upstream commit c0de08d04215031d68fa13af36f347a6cfa252ca ]

If a packet is emitted on one socket in one group of fanout sockets,
it is transmitted again. It is thus read again on one of the sockets
of the fanout group. This result in a loop for software which
generate packets when receiving one.
This retransmission is not the intended behavior: a fanout group
must behave like a single socket. The packet should not be
transmitted on a socket if it originates from a socket belonging
to the same fanout group.

This patch fixes the issue by changing the transmission check to
take fanout group info account.

Reported-by: Aleksandr Kotov 
Signed-off-by: Eric Leblond 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net/core: Fix potential memory leak in dev_set_alias()

2012-10-02T17:29:35+00:00

[ Upstream commit 7364e445f62825758fa61195d237a5b8ecdd06ec ]

Do not leak memory by updating pointer with potentially NULL realloc return value.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: Apply device TSO segment limit earlier

2012-10-02T17:29:34+00:00

[ Upstream commit 1485348d2424e1131ea42efc033cbd9366462b01 ]

Cache the device gso_max_segs in sock::sk_gso_max_segs and use it to
limit the size of TSO skbs.  This avoids the need to fall back to
software GSO for local TCP senders.

Signed-off-by: Ben Hutchings 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: Allow driver to limit number of GSO segments per skb

2012-10-02T17:29:34+00:00

[ Upstream commit 30b678d844af3305cda5953467005cebb5d7b687 ]

A peer (or local user) may cause TCP to use a nominal MSS of as little
as 88 (actual MSS of 76 with timestamps).  Given that we have a
sufficiently prodigious local sender and the peer ACKs quickly enough,
it is nevertheless possible to grow the window for such a connection
to the point that we will try to send just under 64K at once.  This
results in a single skb that expands to 861 segments.

In some drivers with TSO support, such an skb will require hundreds of
DMA descriptors; a substantial fraction of a TX ring or even more than
a full ring.  The TX queue selected for the skb may stall and trigger
the TX watchdog repeatedly (since the problem skb will be retried
after the TX reset).  This particularly affects sfc, for which the
issue is designated as CVE-2012-3412.

Therefore:
1. Add the field net_device::gso_max_segs holding the device-specific
   limit.
2. In netif_skb_features(), if the number of segments is too high then
   mask out GSO features to force fall back to software GSO.

Signed-off-by: Ben Hutchings 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: feed /dev/random with the MAC address when registering a device

2012-08-15T15:10:28+00:00

commit 7bf2357524408b97fec58344caf7397f8140c3fd upstream.

Signed-off-by: "Theodore Ts'o" 
Cc: David Miller 
Cc: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

net: fix rtnetlink IFF_PROMISC and IFF_ALLMULTI handling

2012-08-09T15:31:51+00:00

[ Upstream commit b1beb681cba5358f62e6187340660ade226a5fcc ]

When device flags are set using rtnetlink, IFF_PROMISC and IFF_ALLMULTI
flags are handled specially. Function dev_change_flags sets IFF_PROMISC and
IFF_ALLMULTI bits in dev->gflags according to the passed value but
do_setlink passes a result of rtnl_dev_combine_flags which takes those bits
from dev->flags.

This can be easily trigerred by doing:

tcpdump -i eth0 &
ip l s up eth0

ip sets IFF_UP flag in ifi_flags and ifi_change, which is combined with
IFF_PROMISC by rtnl_dev_combine_flags, causing __dev_change_flags to set
IFF_PROMISC in gflags.

Reported-by: Max Matveev 
Signed-off-by: Jiri Benc 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

splice: fix racy pipe->buffers uses

2012-07-16T16:04:42+00:00

commit 047fe3605235888f3ebcda0c728cb31937eadfe6 upstream.

Dave Jones reported a kernel BUG at mm/slub.c:3474! triggered
by splice_shrink_spd() called from vmsplice_to_pipe()

commit 35f3d14dbbc5 (pipe: add support for shrinking and growing pipes)
added capability to adjust pipe->buffers.

Problem is some paths don't hold pipe mutex and assume pipe->buffers
doesn't change for their duration.

Fix this by adding nr_pages_max field in struct splice_pipe_desc, and
use it in place of pipe->buffers where appropriate.

splice_shrink_spd() loses its struct pipe_inode_info argument.

Reported-by: Dave Jones 
Signed-off-by: Eric Dumazet 
Cc: Jens Axboe 
Cc: Alexander Viro 
Cc: Tom Herbert 
Tested-by: Dave Jones 
Signed-off-by: Jens Axboe 
[bwh: Backported to 3.2:
 - Adjust context in vmsplice_to_pipe()
 - Update one more call to splice_shrink_spd(), from skb_splice_bits()]
Signed-off-by: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

net: remove skb_orphan_try()

2012-07-16T16:03:48+00:00

[ Upstream commit 62b1a8ab9b3660bb820d8dfe23148ed6cda38574 ]

Orphaning skb in dev_hard_start_xmit() makes bonding behavior
unfriendly for applications sending big UDP bursts : Once packets
pass the bonding device and come to real device, they might hit a full
qdisc and be dropped. Without orphaning, the sender is automatically
throttled because sk->sk_wmemalloc reaches sk->sk_sndbuf (assuming
sk_sndbuf is not too big)

We could try to defer the orphaning adding another test in
dev_hard_start_xmit(), but all this seems of little gain,
now that BQL tends to make packets more likely to be parked
in Qdisc queues instead of NIC TX ring, in cases where performance
matters.

Reverts commits :
fc6055a5ba31 net: Introduce skb_orphan_try()
87fd308cfc6b net: skb_tx_hash() fix relative to skb_orphan_try()
and removes SKBTX_DRV_NEEDS_SK_REF flag

Reported-and-bisected-by: Jean-Michel Hautbois 
Signed-off-by: Eric Dumazet 
Tested-by: Oliver Hartkopp 
Acked-by: Oliver Hartkopp 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

netpoll: fix netpoll_send_udp() bugs

2012-07-16T16:03:47+00:00

[ Upstream commit 954fba0274058d27c7c07b5ea07c41b3b7477894 ]

Bogdan Hamciuc diagnosed and fixed following bug in netpoll_send_udp() :

"skb->len += len;" instead of "skb_put(skb, len);"

Meaning that _if_ a network driver needs to call skb_realloc_headroom(),
only packet headers would be copied, leaving garbage in the payload.

However the skb_realloc_headroom() must be avoided as much as possible
since it requires memory and netpoll tries hard to work even if memory
is exhausted (using a pool of preallocated skbs)

It appears netpoll_send_udp() reserved 16 bytes for the ethernet header,
which happens to work for typicall drivers but not all.

Right thing is to use LL_RESERVED_SPACE(dev)
(And also add dev->needed_tailroom of tailroom)

This patch combines both fixes.

Many thanks to Bogdan for raising this issue.

Reported-by: Bogdan Hamciuc 
Signed-off-by: Eric Dumazet 
Tested-by: Bogdan Hamciuc 
Cc: Herbert Xu 
Cc: Neil Horman 
Reviewed-by: Neil Horman 
Reviewed-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman