linux-stable.git/net/core/dev.c, branch v3.2.83

net/core: revert "net: fix __netdev_update_features return.." and add comment

2016-01-22T21:40:09+00:00

commit 17b85d29e82cc3c874a497a8bc5764d6a2b043e2 upstream.

This reverts commit 00ee59271777 ("net: fix __netdev_update_features return
on ndo_set_features failure")
and adds a comment explaining why it's okay to return a value other than
0 upon error. Some drivers might actually change flags and return an
error so it's better to fire a spurious notification rather than miss
these.

CC: Michał Mirosław 
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net: fix __netdev_update_features return on ndo_set_features failure

2015-12-30T02:25:55+00:00

commit 00ee5927177792a6e139d50b6b7564d35705556a upstream.

If ndo_set_features fails __netdev_update_features() will return -1 but
this is wrong because it is expected to return 0 if no features were
changed (see netdev_update_features()), which will cause a netdev
notifier to be called without any actual changes. Fix this by returning
0 if ndo_set_features fails.

Fixes: 6cb6a27c45ce ("net: Call netdev_features_change() from netdev_update_features()")
CC: Michał Mirosław 
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

net: call rcu_read_lock early in process_backlog

2015-08-12T14:33:21+00:00

commit 2c17d27c36dcce2b6bf689f41a46b9e909877c21 upstream.

Incoming packet should be either in backlog queue or
in RCU read-side section. Otherwise, the final sequence of
flush_backlog() and synchronize_net() may miss packets
that can run without device reference:

CPU 1                  CPU 2
                       skb->dev: no reference
                       process_backlog:__skb_dequeue
                       process_backlog:local_irq_enable

on_each_cpu for
flush_backlog =>       IPI(hardirq): flush_backlog
                       - packet not found in backlog

                       CPU delayed ...
synchronize_net
- no ongoing RCU
read-side sections

netdev_run_todo,
rcu_barrier: no
ongoing callbacks
                       __netif_receive_skb_core:rcu_read_lock
                       - too late
free dev
                       process packet for freed dev

Fixes: 6e583ce5242f ("net: eliminate refcounting in backlog queue")
Cc: Eric W. Biederman 
Cc: Stephen Hemminger 
Signed-off-by: Julian Anastasov 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2:
 - Adjust context
 - No need to rename the label in __netif_receive_skb()]
Signed-off-by: Ben Hutchings

net: do not process device backlog during unregistration

2015-08-12T14:33:20+00:00

commit e9e4dd3267d0c5234c5c0f47440456b10875dec9 upstream.

commit 381c759d9916 ("ipv4: Avoid crashing in ip_error")
fixes a problem where processed packet comes from device
with destroyed inetdev (dev->ip_ptr). This is not expected
because inetdev_destroy is called in NETDEV_UNREGISTER
phase and packets should not be processed after
dev_close_many() and synchronize_net(). Above fix is still
required because inetdev_destroy can be called for other
reasons. But it shows the real problem: backlog can keep
packets for long time and they do not hold reference to
device. Such packets are then delivered to upper levels
at the same time when device is unregistered.
Calling flush_backlog after NETDEV_UNREGISTER_FINAL still
accounts all packets from backlog but before that some packets
continue to be delivered to upper levels long after the
synchronize_net call which is supposed to wait the last
ones. Also, as Eric pointed out, processed packets, mostly
from other devices, can continue to add new packets to backlog.

Fix the problem by moving flush_backlog early, after the
device driver is stopped and before the synchronize_net() call.
Then use netif_running check to make sure we do not add more
packets to backlog. We have to do it in enqueue_to_backlog
context when the local IRQ is disabled. As result, after the
flush_backlog and synchronize_net sequence all packets
should be accounted.

Thanks to Eric W. Biederman for the test script and his
valuable feedback!

Reported-by: Vittorio Gambaletta 
Fixes: 6e583ce5242f ("net: eliminate refcounting in backlog queue")
Cc: Eric W. Biederman 
Cc: Stephen Hemminger 
Signed-off-by: Julian Anastasov 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

net: reject creation of netdev names with colons

2015-05-09T22:16:37+00:00

[ Upstream commit a4176a9391868bfa87705bcd2e3b49e9b9dd2996 ]

colons are used as a separator in netdev device lookup in dev_ioctl.c

Specific functions are SIOCGIFTXQLEN SIOCETHTOOL SIOCSIFNAME

Signed-off-by: Matthew Thode 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

net: rps: fix cpu unplug

2015-05-09T22:16:36+00:00

[ Upstream commit ac64da0b83d82abe62f78b3d0e21cca31aea24fa ]

softnet_data.input_pkt_queue is protected by a spinlock that
we must hold when transferring packets from victim queue to an active
one. This is because other cpus could still be trying to enqueue packets
into victim queue.

A second problem is that when we transfert the NAPI poll_list from
victim to current cpu, we absolutely need to special case the percpu
backlog, because we do not want to add complex locking to protect
process_queue : Only owner cpu is allowed to manipulate it, unless cpu
is offline.

Based on initial patch from Prasad Sodagudi & Subash Abhinov
Kasiviswanathan.

This version is better because we do not slow down packet processing,
only make migration safer.

Reported-by: Prasad Sodagudi 
Reported-by: Subash Abhinov Kasiviswanathan 
Signed-off-by: Eric Dumazet 
Cc: Tom Herbert 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net/core: Handle csum for CHECKSUM_COMPLETE VXLAN forwarding

2015-02-20T00:49:41+00:00

[ Upstream commit 2c26d34bbcc0b3f30385d5587aa232289e2eed8e ]

When using VXLAN tunnels and a sky2 device, I have experienced
checksum failures of the following type:

[ 4297.761899] eth0: hw csum failure
[...]
[ 4297.765223] Call Trace:
[ 4297.765224]    [] dump_stack+0x46/0x58
[ 4297.765235]  [] netdev_rx_csum_fault+0x42/0x50
[ 4297.765238]  [] ? skb_push+0x40/0x40
[ 4297.765240]  [] __skb_checksum_complete+0xbc/0xd0
[ 4297.765243]  [] tcp_v4_rcv+0x2e2/0x950
[ 4297.765246]  [] ? ip_rcv_finish+0x360/0x360

	These are reliably reproduced in a network topology of:

container:eth0 == host(OVS VXLAN on VLAN) == bond0 == eth0 (sky2) -> switch

	When VXLAN encapsulated traffic is received from a similarly
configured peer, the above warning is generated in the receive
processing of the encapsulated packet.  Note that the warning is
associated with the container eth0.

        The skbs from sky2 have ip_summed set to CHECKSUM_COMPLETE, and
because the packet is an encapsulated Ethernet frame, the checksum
generated by the hardware includes the inner protocol and Ethernet
headers.

	The receive code is careful to update the skb->csum, except in
__dev_forward_skb, as called by dev_forward_skb.  __dev_forward_skb
calls eth_type_trans, which in turn calls skb_pull_inline(skb, ETH_HLEN)
to skip over the Ethernet header, but does not update skb->csum when
doing so.

	This patch resolves the problem by adding a call to
skb_postpull_rcsum to update the skb->csum after the call to
eth_type_trans.

Signed-off-by: Jay Vosburgh 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net: Fix stacked vlan offload features computation

2015-02-20T00:49:32+00:00

commit 796f2da81bead71ffc91ef70912cd8d1827bf756 upstream.

When vlan tags are stacked, it is very likely that the outer tag is stored
in skb->vlan_tci and skb->protocol shows the inner tag's vlan_proto.
Currently netif_skb_features() first looks at skb->protocol even if there
is the outer tag in vlan_tci, thus it incorrectly retrieves the protocol
encapsulated by the inner vlan instead of the inner vlan protocol.
This allows GSO packets to be passed to HW and they end up being
corrupted.

Fixes: 58e998c6d239 ("offloading: Force software GSO for multiple vlan tags.")
Signed-off-by: Toshiaki Makita 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2:
 - We don't support 802.1ad tag offload
 - Keep passing protocol to harmonize_features()]
Signed-off-by: Ben Hutchings

net-gro: reset skb->truesize in napi_reuse_skb()

2014-06-09T12:29:00+00:00

[ Upstream commit e33d0ba8047b049c9262fdb1fcafb93cb52ceceb ]

Recycling skb always had been very tough...

This time it appears GRO layer can accumulate skb->truesize
adjustments made by drivers when they attach a fragment to skb.

skb_gro_receive() can only subtract from skb->truesize the used part
of a fragment.

I spotted this problem seeing TcpExtPruneCalled and
TcpExtTCPRcvCollapsed that were unexpected with a recent kernel, where
TCP receive window should be sized properly to accept traffic coming
from a driver not overshooting skb->truesize.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net: flow_dissector: fail on evil iph->ihl

2014-01-03T04:33:35+00:00

commit 6f092343855a71e03b8d209815d8c45bf3a27fcd upstream.

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).

Cc: Eric Dumazet 
Cc: Petr Matousek 
Cc: Michael S. Tsirkin 
Cc: Daniel Borkmann 
Signed-off-by: Jason Wang 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: the affected code is in __skb_get_rxhash()]
Signed-off-by: Ben Hutchings