Newly added code in the bnxt driver uses a couple of variables that
are never initialized when CONFIG_BNXT_SRIOV is not set, and gcc
correctly warns about that:

In file included from include/linux/list.h:8:0,
                 from include/linux/module.h:9,
                 from drivers/net/ethernet/broadcom/bnxt/bnxt.c:10:
drivers/net/ethernet/broadcom/bnxt/bnxt.c: In function 'bnxt_get_max_rings':
include/linux/kernel.h:794:26: warning: 'cp' may be used uninitialized in this function [-Wmaybe-uninitialized]
include/linux/kernel.h:794:26: warning: 'tx' may be used uninitialized in this function [-Wmaybe-uninitialized]
drivers/net/ethernet/broadcom/bnxt/bnxt.c:5730:11: warning: 'rx' may be used uninitialized in this function [-Wmaybe-uninitialized]
drivers/net/ethernet/broadcom/bnxt/bnxt.c:5736:6: note: 'rx' was declared here

This changes the condition so that we fall back to using the PF
data if VF is not available, and always initialize the variables
to something useful.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 6e6c5a57 ("bnxt_en: Modify bnxt_get_max_rings() to support shared or non shared rings.")
Acked-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

On ARM64, a BUG() is triggered in the eBPF JIT if a filter with a
constant shift that can't be encoded in the immediate field of the
UBFM/SBFM instructions is passed to the JIT.  Since these shifts
amounts, which are negative or >= regsize, are invalid, reject them in
the eBPF verifier and the classic BPF filter checker, for all
architectures.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Multicast groups are stored in global buffer. Check for needed buffer size
incorrectly compares buffer size to first id for family. This means that
for families with more than one mcast id one may allocate too small buffer
and end up writing rest of the groups to some unallocated memory. Fix the
buffer size check to compare allocated space to last mcast id for the
family.

Tested on ARM using kernel 3.14
Signed-off-by: Matti Vaittinen <matti.vaittinen@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

On ARM64, a BUG() is triggered in the eBPF JIT if a filter with a
constant shift that can't be encoded in the immediate field of the
UBFM/SBFM instructions is passed to the JIT.  Since these shifts
amounts, which are negative or >= regsize, are invalid, reject them in
the eBPF verifier and the classic BPF filter checker, for all
architectures.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ivaylo Dimitrov reported a regression caused by commit 7866a621
("dev: add per net_device packet type chains").

skb->dev becomes NULL and we crash in __netif_receive_skb_core().

Before above commit, different kind of bugs or corruptions could happen
without major crash.

But the root cause is that phonet_rcv() can queue skb without checking
if skb is shared or not.

Many thanks to Ivaylo Dimitrov for his help, diagnosis and tests.
Reported-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Tested-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Remi Denis-Courmont <courmisch@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The offset inside the fragment was not used for the dma address and
silent data corruption resulted because TSO makes the checksum match.

Fixes: 077742da ("dwc_eth_qos: Add support for Synopsys DWC Ethernet QoS")
Signed-off-by: Lars Persson <larper@axis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

It used to be that bus->irq was a pointer but after e7f4dc35
('mdio: Move allocation of interrupts into core') it's an array inside
the mdio struct, so it can never be NULL.  Let's remove the check.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

It used to be that mdio->irq was a pointer but after e7f4dc35
('mdio: Move allocation of interrupts into core') it's an array inside
the mdio struct so it can never be NULL.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If bus = kzalloc() fails then we end up dereferencing bus when we do
"bus->irq[i] = PHY_POLL;".  The code is a little simpler if we reverse
the NULL check and return directly on failure.

Fixes: e7f4dc35 ('mdio: Move allocation of interrupts into core')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Conflicts:
	drivers/net/bonding/bond_main.c
	drivers/net/ethernet/mellanox/mlxsw/spectrum.h
	drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c

The bond_main.c and mellanox switch conflicts were cases of
overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>

Obviously need to 'or in NETIF_F_IP_CSUM and NETIF_F_IPV6_CSUM.

Fixes: c8cd0989 ("net: Eliminate NETIF_F_GEN_CSUM and NETIF_F_V[46]_CSUM")
Reported-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Andrew Lunn says:

====================
More mdio device build failure fixes

These patches fix two build errors reported by Guenter Roeck
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

dev has moved inside the new mdio structure.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

dev has moved inside the new mdio structure.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 1f718f0f ("bonding: populate neighbour's private on enslave")
undoes the fix provided by commit c2edacf8 ("bonding / ipv6: no addrconf
for slaves separately from master") by effectively setting the slave flag
after the slave has been opened.  If the slave comes up quickly enough, it
will go through the IPv6 addrconf before the slave flag has been set and
will get a link local IPv6 address.

In order to ensure that addrconf knows to ignore the slave devices on state
change, set IFF_SLAVE before dev_open() during bonding enslavement.

Fixes: 1f718f0f ("bonding: populate neighbour's private on enslave")
Signed-off-by: Karl Heiss <kheiss@gmail.com>
Signed-off-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Reviewed-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Andy Gospodarek <gospo@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Or Gerlitz says:

====================
net/mlx5_core: Enhance flow steering support

v0 --> v1 changes:
  - fixed improperly formatted comments.
  - compare value of ib_spec->eth.mask.ether_type in network byte order
     in ('IB/mlx5: Add flow steering utilities').

v1 --> v2 changes:
  - made sure that service functions added in the IB driver are only static-fied
    on the last commit, to make sure bisection with -Werror works fine.

v2 --> v3 changes:
   - squashed patches 11 and 12 into one patch, s.t Dave's comment
     on unused static functions gcc complaints during bisection is
     correctly addressed.

v3 has been generated against net-next commit c9c99311 "Merge tag
'batman-adv-for-davem' of git://git.open-mesh.org/linux-merge"

The series is signed by Matan who was revently assigned to a maintainer for
the mlx5_core and IB drivers (this is a 4.5-rc1 change to the maintainers file coming
from the rdma tree) -- as such I didn't see a neeed to add my signature (Or).

This series adds three new functionalists to the driver flow-steering
infrastructure: auto-grouped flow tables, chaining of flow tables and
updates for the root flow table.

1. Auto-grouped flow tables - Flow table with auto grouping management.
When a flow table is created, hints regarding the number of rule types
and the number of rules are given in advance. Thus, a flow table is
divided into #NUM_TYPES+1 groups each contains
(#NUM_RULES)/(#NUM_TYPES+1) rules. The first #NUM_TYPES parts are groups
which are filled if the added rule matches the group specification or
the group is empty. The last part is filled by rules that can't fit
any of the former groups.

2. Chaining flow tables - Flow tables from different priorities are chained
together, if there is no match in flow table of priority i we continue
searching for a match in priority i+1. This is both true if priorities
i and i+1 belongs to the same namespace or not.

3. Updating the root flow table - the root flow table is the flow table
with the lowest level. The hardware start searching for a match in the
root flow table and continue according to the matches it find along
the way.

The first usage for the new functionality is flow steering for user-space
ConnectX-4 offloaded HW Eth RX queues done through the mlx5 IB driver.

When the mlx5 core driver is loaded, it opens three flow namespaces:
1. By-pass namespace (used by mlx5 IB driver).
2. Kernel namespace (used in order to get packets to the networking stack
through mlx5 EN driver).
3. Leftovers namespace (used by mlx5 IB and future sniffer)

The series is built as follows:

Patch #1 introduces auto-grouped flow tables support.

Patch #2 add utility functions for finding the next and the previous
flow tables in different priorities. This is used in order to chain
the flow tables in a downstream patch.

Patch #3 introduces a firmware command for updating the root flow table.

Patch #4 introduces modify flow table firmware command, this command is used
when we want to change the next flow table of an existing flow table.
This is used for chaining flow tables as well.

Patch #5 connect/disconnect flow tables. This is actually the chaining
process when we want to link flow tables. This means that if we couldn't
find a match in the first flow table, we'll continue in the chained
flow table.

Patch #6 updates priority's attributes that is required for flow table
level allocation. We update both the max_fts (the number of allowed FTs
in the sub-tree of this priority) and the start_level (which is the first
level we'll assign to the flow-tables created inside the priority).

Patch #7 adds checking of required device capabilities. Some namespaces
could be only created if the hardware supports certain attributes.
This is especially true for the Bypass and leftovers namespaces. This
adds a generic mechanism to check these required attributes.

Patch #8 creates two additional namespaces:
	a. Bypass flow rules(has nine priorities)
	b. Leftovers packets(have one priority) - for unmatched packets.

Patch #9 re-factors ipv4/ipv6 match fields in the mlx5 firmware interface
header to be more clear.

Patch #10 exports the flow steering API for mlx5_ib usage

Patch #11 implements the required support in mlx5_ib in order
to support the RDMA flow steering verbs.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Adding flow steering support by creating a flow-table per
priority (if rules exist in the priority). mlx5_ib uses
autogrouping and thus only creates the required destinations.

Also includes adding of these flow steering utilities

1. Parsing verbs flow attributes hardware steering specs.

2. Check if flow is multicast - this is required in order to decide
to which flow table will we add the steering rule.

3. Set outer headers in flow match criteria to zeros.
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add exports to flow steering API for mlx5_ib usage.
The following functions are exported:

1. mlx5_create_auto_grouped_flow_table - used to create flow
table with auto flow grouping management (create and destroy
flow groups). In auto-grouped flow tables, we create groups
automatically if needed (if we don't find an existing
flow group with same match criteria when we add new rule).

2. mlx5_destroy_flow_table - used to destroy  a flow table.

3. mlx5_add_flow_rule - used to add flow rule into a flow table.

4. mlx5_del_flow_rule - used to delete flow rule from its flow table.

5. mlx5_get_flow_namespace - used to get a handle to the required
namespace sub-tree.
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Change the mlx5 firmware interface header to make it
more clear which bytes should be used by IPv4 or
IPv6 addresses.
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When the driver is loaded, we create flow steering namespace
for kernel bypass with nine priorities and another namespace
for leftovers(in order to catch packets that weren't matched).
Verbs applications will use these priorities.
we found nine as a number that balances the requirements from the
user and retains performance.

The bypass namespace is used by verbs applications that want to bypass
the kernel networking stack. The leftovers namespace is used by verbs
applications and the sniffer in order to catch packets that weren't
handled by any preceding rules.
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Before we create the sub tree of a steering namespaces(kernel, bypass,
leftovers) we check that the device has the required capabilities
in order to create this subtree.
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Each priority has two attributes:
1. max_ft - maximum allowed flow tables under this priority.
2. start_level - start level range of the flow tables
in the priority.

These attributes are set by traversing the tree nodes by
DFS and set start level and max flow tables to each priority.
Start level depends on the max flow tables of the prior priorities
in the tree.

The leaves of the trees have max_ft set in them. Each node accumulates
the max_ft of its children and set it accordingly.
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Flow tables from different priorities should be chained together.
When a packet arrives we search for a match in the
by-pass flow tables (first we search for a match in priority 0
and if we don't find a match we move to the next priority).
If we can't find a match in any of the bypass flow-tables, we continue
searching in the flow-tables of the next priority, which are the
kernel's flow tables.

Setting the miss flow table in a new flow table to be the next one in
the list is performed via create flow table API. If we want to change an
existing flow table, for example in order to point from an
existing flow table to the new next-in-list flow table, we use the
modify flow table API.
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Introduce the modify flow table command. This command is used when
we want to change the next flow table of an existing flow table.
The next flow table is defined as the table we search (in order
to find a match), if we couldn't find a match in any of the flow table
entries in the current flow table.
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The root Flow Table for each Flow Table Type is defined,
by default, as the Flow Table with level 0.

In order not to use an empty flow tables and introduce new hops,
but still preserve space for flow-tables that have a priority
greater(lower number) than the current flow table, we introduce this
new set root flow table command.
This command tells the HW to start matching packets from the
assigned root flow table.
This command is used when we create new flow table with level lower than the
current lowest flow table or it is the first flow table.
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add two utility functions for find next and prev flow table.
Find next flow table function gets priority and return the
first flow table of the next priority in the tree.
Find prev flow table return the last flow table of
the previous priority in the tree.

These utility functions are used for chaining flow table from different
priorities.
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When user add rule to autogrouped flow table, we search
for flow group with the same match criteria, if we don't
find such group then we create new flow group with the
required match criteria and insert the rule to this group.

We divide the flow table into required_groups + 1,
in order to reserve a part of the flow table for rules
which don't match any existing group.
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit acf8dd0a ("udp: only allow UFO for packets from SOCK_DGRAM
sockets") disallows UFO for packets sent from raw sockets. We need to do
the same also for SOCK_DGRAM sockets with SO_NO_CHECK options, even if
for a bit different reason: while such socket would override the
CHECKSUM_PARTIAL set by ip_ufo_append_data(), gso_size is still set and
bad offloading flags warning is triggered in __skb_gso_segment().

In the IPv6 case, SO_NO_CHECK option is ignored but we need to disallow
UFO for packets sent by sockets with UDP_NO_CHECK6_TX option.
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Tested-by: Shannon Nelson <shannon.nelson@intel.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix possible null pointer dereference that may occur when calling
skb_reserve() on a null skb.

Fixes: 879c7220 ("net: pktgen: Observe needed_headroom of the device")
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Daniel Borkmann says:

====================
BPF update

This set adds IPv6 support for bpf_skb_{set,get}_tunnel_key() helper.
It also exports flags to user space that are being used in helpers and
weren't exported thus far. For more details, please see the individual
patches.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

After IPv6 support has recently been added to metadata dst and related
encaps, add support for populating/reading it from an eBPF program.

Commit d3aa45ce ("bpf: add helpers to access tunnel metadata") started
with initial IPv4-only support back then (due to IPv6 metadata support
not being available yet).

To stay compatible with older programs, we need to test for the passed
structure size. Also TOS and TTL support from the ip_tunnel_info key has
been added. Tested with vxlan devs in collect meta data mode with IPv4,
IPv6 and in compat mode over different network namespaces.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Export flags used by eBPF helper functions through UAPI, so they can be
used by programs (instead of them redefining all flags each time or just
using the hard-coded values). It also gives a better overview what flags
are used where and we can further get rid of the extra macros defined in
filter.c. Moreover, reject invalid flags.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Sergei Shtylyov says:

====================
Fix some dubious code in the Renesas Ethernet drivers

   Here's a set of 2 patches against DaveM's 'net.git' repo. While initializing
EMAC the code tries to respect the duplex mode both programmed into ECMR and
stored in its own private data -- this just can't be right.

[1/2] ravb: stop reading ECMR in ravb_emac_init()
[2/2] sh_eth: stop reading ECMR in sh_eth_dev_init()
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The code in sh_eth_dev_init()  twiddling the ECMR bits always looked a bit
strange to me:  if one intends to respect 'mdp->duplex', why save old value
of the ECMR.DM bit? As all the other bits are zeroed anyway, we don't really
need to read ECMR before writing to it.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The code in ravb_emac_init() twiddling the ECMR bits always looked a bit
strange to me: if one intends to respect 'priv->duplex', why save old value
of the ECMR.DM bit?   As all the other bits are zeroed anyway, we don't
really need to read ECMR before writing to it.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

only when user space passes the addresses should we consider their
presence
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

For tcp_yeah, use an ssthresh floor of 2, the same floor used by Reno
and CUBIC, per RFC 5681 (equation 4).

tcp_yeah_ssthresh() was sometimes returning a 0 or negative ssthresh
value if the intended reduction is as big or bigger than the current
cwnd. Congestion control modules should never return a zero or
negative ssthresh. A zero ssthresh generally results in a zero cwnd,
causing the connection to stall. A negative ssthresh value will be
interpreted as a u32 and will set a target cwnd for PRR near 4
billion.

Oleksandr Natalenko reported that a system using tcp_yeah with ECN
could see a warning about a prior_cwnd of 0 in
tcp_cwnd_reduction(). Testing verified that this was due to
tcp_yeah_ssthresh() misbehaving in this way.
Reported-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The spew in /proc/net/bonding/bond0 uses netif_carrier_ok() to determine
mii_status, while /sys/class/net/bond0/bonding/mii_status looks at
curr_active_slave, which doesn't actually seem to be set sometimes when
the bond actually is up. A mode 4 bond configured via ifcfg-foo files on a
Red Hat Enterprise Linux system, after boot, comes up clean and
functional, but the sysfs node shows mii_status of down, while proc shows
up. A simple enough fix here seems to be to use the same method for
determining up or down in both places, and I'd opt for the one that seems
to match reality.

CC: Jay Vosburgh <j.vosburgh@gmail.com>
CC: Veaceslav Falico <vfalico@gmail.com>
CC: Andy Gospodarek <gospo@cumulusnetworks.com>
CC: netdev@vger.kernel.org
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Dmitry Vyukov reported a use-after-free in the code expanded by the
macro debug_post_sfx, which is caused by the use of the asoc pointer
after it was freed within sctp_side_effect() scope.

This patch fixes it by allowing sctp_side_effect to clear that asoc
pointer when the TCB is freed.

As Vlad explained, we also have to cover the SCTP_DISPOSITION_ABORT case
because it will trigger DELETE_TCB too on that same loop.

Also, there were places issuing SCTP_CMD_INIT_FAILED and ASSOC_FAILED
but returning SCTP_DISPOSITION_CONSUME, which would fool the scheme
above. Fix it by returning SCTP_DISPOSITION_ABORT instead.

The macro is already prepared to handle such NULL pointer.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>