The user tool modinfo is used to get information on kernel modules, including a
description where it is available.
This patch adds a brief MODULE_DESCRIPTION to the following modules:
9p
drop_monitor
esp4_offload
esp6_offload
fou
fou6
ila
sch_fq
sch_fq_codel
sch_hhf
Signed-off-by: Rob Gill <rrobgill@protonmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When submitting v2 of "fou: Support binding FoU socket" (1713cb37bf),
I accidentally sent the wrong version of the patch and one fix was
missing. In the initial version of the patch, as well as the version 2
that I submitted, I incorrectly used ".type" for the two V6-attributes.
The correct is to use ".len".
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Fixes: 1713cb37bf ("fou: Support binding FoU socket")
Signed-off-by: Kristian Evensen <kristian.evensen@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have MODULE_LICENCE("GPL*") inside which was used in the initial
scan/conversion to ignore the file
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add options to strictly validate messages and dump messages,
sometimes perhaps validating dump messages non-strictly may
be required, so add an option for that as well.
Since none of this can really be applied to existing commands,
set the options everwhere using the following spatch:
@@
identifier ops;
expression X;
@@
struct genl_ops ops[] = {
...,
{
.cmd = X,
+ .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
...
},
...
};
For new commands one should just not copy the .validate 'opt-out'
flags and thus get strict validation.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Remove not useful protocol version check in gue_udp_recv since just
gue version 0 can hit that code. Moreover remove duplicated hdrlen
computation
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
gue tunnels run iptunnel_pull_offloads on received skbs. This can
determine a possible use-after-free accessing guehdr pointer since
the packet will be 'uncloned' running pskb_expand_head if it is a
cloned gso skb (e.g if the packet has been sent though a veth device)
Fixes: a09a4c8dd1 ("tunnels: Remove encapsulation offloads on decap")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Correct spelling of encapsulation.
Found by inspection.
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
An FoU socket is currently bound to the wildcard-address. While this
works fine, there are several use-cases where the use of the
wildcard-address is not desirable. For example, I use FoU on some
multi-homed servers and would like to use FoU on only one of the
interfaces.
This commit adds support for binding FoU sockets to a given source
address/interface, as well as connecting the socket to a given
destination address/port. udp_tunnel already provides the required
infrastructure, so most of the code added is for exposing and setting
the different attributes (local address, peer address, etc.).
The lookups performed when we add, delete or get an FoU-socket has also
been updated to compare all the attributes a user can set. Since the
comparison now involves several elements, I have added a separate
comparison-function instead of open-coding.
In order to test the code and ensure that the new comparison code works
correctly, I started by creating a wildcard socket bound to port 1234 on
my machine. I then tried to create a non-wildcarded socket bound to the
same port, as well as fetching and deleting the socket (including source
address, peer address or interface index in the netlink request). Both
the create, fetch and delete request failed. Deleting/fetching the
socket was only successful when my netlink request attributes matched
those used to create the socket.
I then repeated the tests, but with a socket bound to a local ip
address, a socket bound to a local address + interface, and a bound
socket that was also «connected» to a peer. Add only worked when no
socket with the matching source address/interface (or wildcard) existed,
while fetch/delete was only successful when all attributes matched.
In addition to testing that the new code work, I also checked that the
current behavior is kept. If none of the new attributes are provided,
then an FoU-socket is configured as before (i.e., wildcarded). If any
of the new attributes are provided, the FoU-socket is configured as
expected.
v1->v2:
* Fixed building with IPv6 disabled (kbuild).
* Fixed a return type warning and make the ugly comparison function more
readable (kbuild).
* Describe more in detail what has been tested (thanks David Miller).
* Make peer port required if peer address is specified.
Signed-off-by: Kristian Evensen <kristian.evensen@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since maxattr is common, the policy can't really differ sanely,
so make it common as well.
The only user that did in fact manage to make a non-common policy
is taskstats, which has to be really careful about it (since it's
still using a common maxattr!). This is no longer supported, but
we can fake it using pre_doit.
This reduces the size of e.g. nl80211.o (which has lots of commands):
text data bss dec hex filename
398745 14323 2240 415308 6564c net/wireless/nl80211.o (before)
397913 14331 2240 414484 65314 net/wireless/nl80211.o (after)
--------------------------------
-832 +8 0 -824
Which is obviously just 8 bytes for each command, and an added 8
bytes for the new policy pointer. I'm not sure why the ops list is
counted as .text though.
Most of the code transformations were done using the following spatch:
@ops@
identifier OPS;
expression POLICY;
@@
struct genl_ops OPS[] = {
...,
{
- .policy = POLICY,
},
...
};
@@
identifier ops.OPS;
expression ops.POLICY;
identifier fam;
expression M;
@@
struct genl_family fam = {
.ops = OPS,
.maxattr = M,
+ .policy = POLICY,
...
};
This also gets rid of devlink_nl_cmd_region_read_dumpit() accessing
the cb->data as ops, which we want to change in a later genl patch.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In commit 11789039da ("fou: Prevent unbounded recursion in GUE error
handler"), I didn't take care of the case where UDP-Lite is encapsulated
into UDP or UDP-Lite with GUE. From a syzbot report about a possibly
similar issue with GUE on IPv6, I just realised the same thing might
happen with a UDP-Lite inner payload.
Also skip exception handling for inner UDP-Lite protocol.
Fixes: 11789039da ("fou: Prevent unbounded recursion in GUE error handler")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Handling exceptions for direct UDP encapsulation in GUE (that is,
UDP-in-UDP) leads to unbounded recursion in the GUE exception handler,
syzbot reported.
While draft-ietf-intarea-gue-06 doesn't explicitly forbid direct
encapsulation of UDP in GUE, it probably doesn't make sense to set up GUE
this way, and it's currently not even possible to configure this.
Skip exception handling if the GUE proto/ctype field is set to the UDP
protocol number. Should we need to handle exceptions for UDP-in-GUE one
day, we might need to either explicitly set a bound for recursion, or
implement a special iterative handling for these cases.
Reported-and-tested-by: syzbot+43f6755d1c2e62743468@syzkaller.appspotmail.com
Fixes: b8a51b38e4 ("fou, fou6: ICMP error handlers for FoU and GUE")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As the destination port in FoU and GUE receiving sockets doesn't
necessarily match the remote destination port, we can't associate errors
to the encapsulating tunnels with a socket lookup -- we need to blindly
try them instead. This means we don't even know if we are handling errors
for FoU or GUE without digging into the packets.
Hence, implement a single handler for both, one for IPv4 and one for IPv6,
that will check whether the packet that generated the ICMP error used a
direct IP encapsulation or if it had a GUE header, and send the error to
the matching protocol handler, if any.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Simple overlapping changes in stmmac driver.
Adjust skb_gro_flush_final_remcsum function signature to make GRO list
changes in net-next, as per Stephen Rothwell's example merge
resolution.
Signed-off-by: David S. Miller <davem@davemloft.net>
Since the addition of GRO for ESP, gro_receive can consume the skb and
return -EINPROGRESS. In that case, the lower layer GRO handler cannot
touch the skb anymore.
Commit 5f114163f2 ("net: Add a skb_gro_flush_final helper.") converted
some of the gro_receive handlers that can lead to ESP's gro_receive so
that they wouldn't access the skb when -EINPROGRESS is returned, but
missed other spots, mainly in tunneling protocols.
This patch finishes the conversion to using skb_gro_flush_final(), and
adds a new helper, skb_gro_flush_final_remcsum(), used in VXLAN and
GUE.
Fixes: 5f114163f2 ("net: Add a skb_gro_flush_final helper.")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Manage pending per-NAPI GRO packets via list_head.
Return an SKB pointer from the GRO receive handlers. When GRO receive
handlers return non-NULL, it means that this SKB needs to be completed
at this time and removed from the NAPI queue.
Several operations are greatly simplified by this transformation,
especially timing out the oldest SKB in the list when gro_count
exceeds MAX_GRO_SKBS, and napi_gro_flush() which walks the queue
in reverse order.
Signed-off-by: David S. Miller <davem@davemloft.net>
In the case that GRO is turned on and the original received packet is
CHECKSUM_PARTIAL, if the outer UDP header is exactly at the last
csum-unnecessary point, which for instance could occur if the packet
comes from another Linux guest on the same Linux host, we have to do
either remcsum_adjust or set up CHECKSUM_PARTIAL again with its
csum_start properly reset considering RCO.
However, since b7fe10e5eb ("gro: Fix remcsum offload to deal with frags
in GRO") that barrier in such case could be skipped if GRO turned on,
hence we pass over it and the inner L4 validation mistakenly reckons
it as a bad csum.
This patch makes remcsum_offload being reset at the same time of GRO
remcsum cleanup, so as to make it work in such case as before.
Fixes: b7fe10e5eb ("gro: Fix remcsum offload to deal with frags in GRO")
Signed-off-by: Koichiro Den <den@klaipeden.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The build header functions are not used by any other code.
net/ipv6/fou6.c:36:5: warning: no previous prototype for ‘fou6_build_header’ [-Wmissing-prototypes]
net/ipv6/fou6.c:54:5: warning: no previous prototype for ‘gue6_build_header’ [-Wmissing-prototypes]
Need to do some code rearranging to satisfy different Kconfig possiblities.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Mostly simple overlapping changes.
For example, David Ahern's adjacency list revamp in 'net-next'
conflicted with an adjacency list traversal bug fix in 'net'.
Signed-off-by: David S. Miller <davem@davemloft.net>
Now genl_register_family() is the only thing (other than the
users themselves, perhaps, but I didn't find any doing that)
writing to the family struct.
In all families that I found, genl_register_family() is only
called from __init functions (some indirectly, in which case
I've add __init annotations to clarifly things), so all can
actually be marked __ro_after_init.
This protects the data structure from accidental corruption.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Instead of providing macros/inline functions to initialize
the families, make all users initialize them statically and
get rid of the macros.
This reduces the kernel code size by about 1.6k on x86-64
(with allyesconfig).
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Static family IDs have never really been used, the only
use case was the workaround I introduced for those users
that assumed their family ID was also their multicast
group ID.
Additionally, because static family IDs would never be
reserved by the generic netlink code, using a relatively
low ID would only work for built-in families that can be
registered immediately after generic netlink is started,
which is basically only the control family (apart from
the workaround code, which I also had to add code for so
it would reserve those IDs)
Thus, anything other than GENL_ID_GENERATE is flawed and
luckily not used except in the cases I mentioned. Move
those workarounds into a few lines of code, and then get
rid of GENL_ID_GENERATE entirely, making it more robust.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, GRO can do unlimited recursion through the gro_receive
handlers. This was fixed for tunneling protocols by limiting tunnel GRO
to one level with encap_mark, but both VLAN and TEB still have this
problem. Thus, the kernel is vulnerable to a stack overflow, if we
receive a packet composed entirely of VLAN headers.
This patch adds a recursion counter to the GRO layer to prevent stack
overflow. When a gro_receive function hits the recursion limit, GRO is
aborted for this skb and it is processed normally. This recursion
counter is put in the GRO CB, but could be turned into a percpu counter
if we run out of space in the CB.
Thanks to Vladimír Beneš <vbenes@redhat.com> for the initial bug report.
Fixes: CVE-2016-7039
Fixes: 9b174d88c2 ("net: Add Transparent Ethernet Bridging GRO support.")
Fixes: 66e5133f19 ("vlan: Add GRO support for non hardware accelerated vlan")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch implements direct encapsulation of IPv4 and IPv6 packets
in UDP. This is done a version "1" of GUE and as explained in I-D
draft-ietf-nvo3-gue-03.
Changes here are only in the receive path, fou with IPxIPx already
supports the transmit side. Both the normal receive path and
GRO path are modified to check for GUE version and check for
IP version in the case that GUE version is "1".
Tested:
IPIP with direct GUE encap
1 TCP_STREAM
4530 Mbps
200 TCP_RR
1297625 tps
135/232/444 90/95/99% latencies
IP4IP6 with direct GUE encap
1 TCP_STREAM
4903 Mbps
200 TCP_RR
1184481 tps
149/253/473 90/95/99% latencies
IP6IP6 direct GUE encap
1 TCP_STREAM
5146 Mbps
200 TCP_RR
1202879 tps
146/251/472 90/95/99% latencies
SIT with direct GUE encap
1 TCP_STREAM
6111 Mbps
200 TCP_RR
1250337 tps
139/241/467 90/95/99% latencies
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds receive path support for IPv6 with fou.
- Add address family to fou structure for open sockets. This supports
AF_INET and AF_INET6. Lookups for fou ports are performed on both the
port number and family.
- In fou and gue receive adjust tot_len in IPv4 header or payload_len
based on address family.
- Allow AF_INET6 in FOU_ATTR_AF netlink attribute.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Create __fou_build_header and __gue_build_header. These implement the
protocol generic parts of building the fou and gue header.
fou_build_header and gue_build_header implement the IPv4 specific
functions and call the __*_build_header functions.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use helper function to set up UDP tunnel related information for a fou
socket.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In netdevice.h we removed the structure in net-next that is being
changes in 'net'. In macsec.c and rtnetlink.c we have overlaps
between fixes in 'net' and the u64 attribute changes in 'net-next'.
The mlx5 conflicts have to do with vxlan support dependencies.
Signed-off-by: David S. Miller <davem@davemloft.net>
UDP tunnel segmentation code relies on the inner offsets being set for
an UDP tunnel GSO packet, but the inner *_complete() functions will
set the inner offsets only if 'encapsulation' is set before calling
them. Currently, udp_gro_complete() sets 'encapsulation' only after
the inner *_complete() functions are done. This causes the inner
offsets having invalid values after udp_gro_complete() returns, which
in turn will make it impossible to properly segment the packet in case
it needs to be forwarded, which would be visible to the user either as
invalid packets being sent or as packet loss.
This patch fixes this by setting skb's 'encapsulation' in
udp_gro_complete() before calling into the inner complete functions,
and by making each possible UDP tunnel gro_complete() callback set the
inner_mac_header to the beginning of the tunnel payload.
Signed-off-by: Jarno Rajahalme <jarno@ovn.org>
Reviewed-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The setting of the UDP tunnel GSO type is already performed by
udp[46]_gro_complete().
Signed-off-by: Jarno Rajahalme <jarno@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch updates the IP tunnel core function iptunnel_handle_offloads so
that we return an int and do not free the skb inside the function. This
actually allows us to clean up several paths in several tunnels so that we
can free the skb at one point in the path without having to have a
secondary path if we are supporting tunnel offloads.
In addition it should resolve some double-free issues I have found in the
tunnels paths as I believe it is possible for us to end up triggering such
an event in the case of fou or gue.
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes an issue I found in which we were dropping frames if we
had enabled checksums on GRE headers that were encapsulated by either FOU
or GUE. Without this patch I was barely able to get 1 Gb/s of throughput.
With this patch applied I am now at least getting around 6 Gb/s.
The issue is due to the fact that with FOU or GUE applied we do not provide
a transport offset pointing to the GRE header, nor do we offload it in
software as the GRE header is completely skipped by GSO and treated like a
VXLAN or GENEVE type header. As such we need to prevent the stack from
generating it and also prevent GRE from generating it via any interface we
create.
Fixes: c3483384ee ("gro: Allow tunnel stacking in the case of FOU/GUE")
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Adapt gue_gro_receive, gue_gro_complete to take a socket argument.
Don't set udp_offloads any more.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch should fix the issues seen with a recent fix to prevent
tunnel-in-tunnel frames from being generated with GRO. The fix itself is
correct for now as long as we do not add any devices that support
NETIF_F_GSO_GRE_CSUM. When such a device is added it could have the
potential to mess things up due to the fact that the outer transport header
points to the outer UDP header and not the GRE header as would be expected.
Fixes: fac8e0f579 ("tunnels: Don't apply GRO to multiple layers of encapsulation.")
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If a packet is either locally encapsulated or processed through GRO
it is marked with the offloads that it requires. However, when it is
decapsulated these tunnel offload indications are not removed. This
means that if we receive an encapsulated TCP packet, aggregate it with
GRO, decapsulate, and retransmit the resulting frame on a NIC that does
not support encapsulation, we won't be able to take advantage of hardware
offloads even though it is just a simple TCP packet at this point.
This fixes the problem by stripping off encapsulation offload indications
when packets are decapsulated.
The performance impacts of this bug are significant. In a test where a
Geneve encapsulated TCP stream is sent to a hypervisor, GRO'ed, decapsulated,
and bridged to a VM performance is improved by 60% (5Gbps->8Gbps) as a
result of avoiding unnecessary segmentation at the VM tap interface.
Reported-by: Ramu Ramamurthy <sramamur@linux.vnet.ibm.com>
Fixes: 68c33163 ("v4 GRE: Add TCP segmentation offload for GRE")
Signed-off-by: Jesse Gross <jesse@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch updates the GRO handlers for GRE, VXLAN, GENEVE, and FOU so that
we do not clear the flush bit until after we have called the next level GRO
handler. Previously this was being cleared before parsing through the list
of frames, however this resulted in several paths where either the bit
needed to be reset but wasn't as in the case of FOU, or cases where it was
being set as in GENEVE. By just deferring the clearing of the bit until
after the next level protocol has been parsed we can avoid any unnecessary
bit twiddling and avoid bugs.
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
All users now pass false, so we can remove it, and remove the code that
was conditional upon it.
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
udp tunnel offloads tend to aggregate datagrams based on inner
headers. gro engine gets notified by tunnel implementations about
possible offloads. The match is solely based on the port number.
Imagine a tunnel bound to port 53, the offloading will look into all
DNS packets and tries to aggregate them based on the inner data found
within. This could lead to data corruption and malformed DNS packets.
While this patch minimizes the problem and helps an administrator to find
the issue by querying ip tunnel/fou, a better way would be to match on
the specific destination ip address so if a user space socket is bound
to the same address it will conflict.
Cc: Tom Herbert <tom@herbertland.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
fou->udp_offloads is managed by RCU. As it is actually included inside
the fou sockets, we cannot let the memory go out of scope before a grace
period. We either can synchronize_rcu or switch over to kfree_rcu to
manage the sockets. kfree_rcu seems appropriate as it is used by vxlan
and geneve.
Fixes: 23461551c0 ("fou: Support for foo-over-udp RX path")
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
fou does not really support IPv6 encapsulation. After an UDP socket is
created in fou_create, the encap_rcv callback is set either to fou_udp_recv
or to gue_udp_recv. Both of those unconditionally assume that the received
packet has an IPv4 header and access the data at network_header as it was an
IPv4 header. This leads to IPv6 flow label being interpreted as IP packet
length, etc.
Disallow fou tunnel to be configured as IPv6 until real IPv6 support is
added to fou.
CC: Tom Herbert <tom@herbertland.com>
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Do WARN_ON_ONCE instead of WARN_ON in gue_gro_receive when the offload
callcaks are bad (either don't exist or gro_receive is not specified).
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The remote checksum offload GRO did not consider the case that frag0
might be in use. This patch fixes that by accessing headers using the
skb_gro functions and not saving offsets relative to skb->head.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fixes: 7a6c8c34e5 ("fou: implement FOU_CMD_GET")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The dwmac-socfpga.c conflict was a case of a bug fix overlapping
changes in net-next to handle an error pointer differently.
Signed-off-by: David S. Miller <davem@davemloft.net>