linux-stable.git/net/core/dev.c, branch linux-3.6.y

net-rps: Fix brokeness causing OOO packets

2012-11-26T20:14:19+00:00

[ Upstream commit baefa31db2f2b13a05d1b81bdf2d20d487f58b0a ]

In commit c445477d74ab3779 which adds aRFS to the kernel, the CPU
selected for RFS is not set correctly when CPU is changing.
This is causing OOO packets and probably other issues.

Signed-off-by: Tom Herbert 
Acked-by: Eric Dumazet 
Acked-by: Ben Hutchings 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

af-packet: fix oops when socket is not present

2012-11-17T21:19:04+00:00

[ Upstream commit a3d744e995d2b936c500585ae39d99ee251c89b4 ]

Due to a NULL dereference, the following patch is causing oops
in normal trafic condition:

commit c0de08d04215031d68fa13af36f347a6cfa252ca
Author: Eric Leblond 
Date:   Thu Aug 16 22:02:58 2012 +0000

    af_packet: don't emit packet on orig fanout group

This buggy patch was a feature fix and has reached most stable
branches.

When skb->sk is NULL and when packet fanout is used, there is a
crash in match_fanout_group where skb->sk is accessed.
This patch fixes the issue by returning false as soon as the
socket is NULL: this correspond to the wanted behavior because
the kernel as to resend the skb to all the listening socket in
this case.

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

vlan: don't deliver frames for unknown vlans to protocols

2012-10-28T17:56:17+00:00

[ Upstream commit 48cc32d38a52d0b68f91a171a8d00531edc6a46e ]

6a32e4f9dd9219261f8856f817e6655114cfec2f made the vlan code skip marking
vlan-tagged frames for not locally configured vlans as PACKET_OTHERHOST if
there was an rx_handler, as the rx_handler could cause the frame to be received
on a different (virtual) vlan-capable interface where that vlan might be
configured.

As rx_handlers do not necessarily return RX_HANDLER_ANOTHER, this could cause
frames for unknown vlans to be delivered to the protocol stack as if they had
been received untagged.

For example, if an ipv6 router advertisement that's tagged for a locally not
configured vlan is received on an interface with macvlan interfaces attached,
macvlan's rx_handler returns RX_HANDLER_PASS after delivering the frame to the
macvlan interfaces, which caused it to be passed to the protocol stack, leading
to ipv6 addresses for the announced prefix being configured even though those
are completely unusable on the underlying interface.

The fix moves marking as PACKET_OTHERHOST after the rx_handler so the
rx_handler, if there is one, sees the frame unchanged, but afterwards,
before the frame is delivered to the protocol stack, it gets marked whether
there is an rx_handler or not.

Signed-off-by: Florian Zumbiehl 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: do not disable sg for packets requiring no checksum

2012-09-21T02:23:40+00:00

A change in a series of VLAN-related changes appears to have
inadvertently disabled the use of the scatter gather feature of
network cards for transmission of non-IP ethernet protocols like ATA
over Ethernet (AoE).  Below is a reference to the commit that
introduces a "harmonize_features" function that turns off scatter
gather when the NIC does not support hardware checksumming for the
ethernet protocol of an sk buff.

  commit f01a5236bd4b140198fbcc550f085e8361fd73fa
  Author: Jesse Gross 
  Date:   Sun Jan 9 06:23:31 2011 +0000

      net offloading: Generalize netif_get_vlan_features().

The can_checksum_protocol function is not equipped to consider a
protocol that does not require checksumming.  Calling it for a
protocol that requires no checksum is inappropriate.

The patch below has harmonize_features call can_checksum_protocol when
the protocol needs a checksum, so that the network layer is not forced
to perform unnecessary skb linearization on the transmission of AoE
packets.  Unnecessary linearization results in decreased performance
and increased memory pressure, as reported here:

  http://www.spinics.net/lists/linux-mm/msg15184.html

The problem has probably not been widely experienced yet, because
only recently has the kernel.org-distributed aoe driver acquired the
ability to use payloads of over a page in size, with the patchset
recently included in the mm tree:

  https://lkml.org/lkml/2012/8/28/140

The coraid.com-distributed aoe driver already could use payloads of
greater than a page in size, but its users generally do not use the
newest kernels.

Signed-off-by: Ed Cashin 
Signed-off-by: David S. Miller

net: fix memory leak on oom with zerocopy

2012-09-18T20:24:00+00:00

If orphan flags fails, we don't free the skb
on receive, which leaks the skb memory.

Return value was also wrong: netif_receive_skb
is supposed to return NET_RX_DROP, not ENOMEM.

Signed-off-by: Michael S. Tsirkin 
Signed-off-by: David S. Miller

net: small bug on rxhash calculation

2012-09-08T22:41:48+00:00

In the current rxhash calculation function, while the
sorting of the ports/addrs is coherent (you get the
same rxhash for packets sharing the same 4-tuple, in
both directions), ports and addrs are sorted
independently. This implies packets from a connection
between the same addresses but crossed ports hash to
the same rxhash.

For example, traffic between A=S:l and B=L:s is hashed
(in both directions) from {L, S, {s, l}}. The same
rxhash is obtained for packets between C=S:s and D=L:l.

This patch ensures that you either swap both addrs and ports,
or you swap none. Traffic between A and B, and traffic
between C and D, get their rxhash from different sources
({L, S, {l, s}} for A<->B, and {L, S, {s, l}} for C<->D)

The patch is co-written with Eric Dumazet 

Signed-off-by: Chema Gonzalez 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

net/core/dev.c: fix kernel-doc warning

2012-08-20T10:00:55+00:00

Fix kernel-doc warning:

Warning(net/core/dev.c:5745): No description found for parameter 'dev'

Signed-off-by: Randy Dunlap 
Cc:	"David S. Miller" 
Cc:	netdev@vger.kernel.org
Signed-off-by: David S. Miller

af_packet: don't emit packet on orig fanout group

2012-08-20T09:37:29+00:00

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

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

2012-08-08T23:06:23+00:00

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

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

2012-08-02T07:19:17+00:00

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