Commit Graph

169 Commits

Author SHA1 Message Date
Serhey Popovych
07f615574f ipv6: Do not leak throw route references
While commit 73ba57bfae ("ipv6: fix backtracking for throw routes")
does good job on error propagation to the fib_rules_lookup()
in fib rules core framework that also corrects throw routes
handling, it does not solve route reference leakage problem
happened when we return -EAGAIN to the fib_rules_lookup()
and leave routing table entry referenced in arg->result.

If rule with matched throw route isn't last matched in the
list we overwrite arg->result losing reference on throw
route stored previously forever.

We also partially revert commit ab997ad408 ("ipv6: fix the
incorrect return value of throw route") since we never return
routing table entry with dst.error == -EAGAIN when
CONFIG_IPV6_MULTIPLE_TABLES is on. Also there is no point
to check for RTF_REJECT flag since it is always set throw
route.

Fixes: 73ba57bfae ("ipv6: fix backtracking for throw routes")
Signed-off-by: Serhey Popovych <serhe.popovych@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-20 15:34:02 -04:00
Sabrina Dubroca
67e194007b ipv6: make ECMP route replacement less greedy
Commit 2759647247 ("ipv6: fix ECMP route replacement") introduced a
loop that removes all siblings of an ECMP route that is being
replaced. However, this loop doesn't stop when it has replaced
siblings, and keeps removing other routes with a higher metric.
We also end up triggering the WARN_ON after the loop, because after
this nsiblings < 0.

Instead, stop the loop when we have taken care of all routes with the
same metric as the route being replaced.

  Reproducer:
  ===========
    #!/bin/sh

    ip netns add ns1
    ip netns add ns2
    ip -net ns1 link set lo up

    for x in 0 1 2 ; do
        ip link add veth$x netns ns2 type veth peer name eth$x netns ns1
        ip -net ns1 link set eth$x up
        ip -net ns2 link set veth$x up
    done

    ip -net ns1 -6 r a 2000::/64 nexthop via fe80::0 dev eth0 \
            nexthop via fe80::1 dev eth1 nexthop via fe80::2 dev eth2
    ip -net ns1 -6 r a 2000::/64 via fe80::42 dev eth0 metric 256
    ip -net ns1 -6 r a 2000::/64 via fe80::43 dev eth0 metric 2048

    echo "before replace, 3 routes"
    ip -net ns1 -6 r | grep -v '^fe80\|^ff00'
    echo

    ip -net ns1 -6 r c 2000::/64 nexthop via fe80::4 dev eth0 \
            nexthop via fe80::5 dev eth1 nexthop via fe80::6 dev eth2

    echo "after replace, only 2 routes, metric 2048 is gone"
    ip -net ns1 -6 r | grep -v '^fe80\|^ff00'

Fixes: 2759647247 ("ipv6: fix ECMP route replacement")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-13 12:16:17 -07:00
David Ahern
16a16cd35e net: ipv6: Change notifications for multipath delete to RTA_MULTIPATH
If an entire multipath route is deleted using prefix and len (without any
nexthops), send a single RTM_DELROUTE notification with the full route
using RTA_MULTIPATH. This is done by generating the skb before the route
delete when all of the sibling routes are still present but sending it
after the route has been removed from the FIB. The skip_notify flag
is used to tell the lower fib code not to send notifications for the
individual nexthop routes.

If a route is deleted using RTA_MULTIPATH for any nexthops or a single
nexthop entry is deleted, then the nexthops are deleted one at a time with
notifications sent as each hop is deleted. This is necessary given that
IPv6 allows individual hops within a route to be deleted.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-04 19:58:14 -05:00
David Ahern
3b1137fe74 net: ipv6: Change notifications for multipath add to RTA_MULTIPATH
Change ip6_route_multipath_add to send one notifciation with the full
route encoded with RTA_MULTIPATH instead of a series of individual routes.
This is done by adding a skip_notify flag to the nl_info struct. The
flag is used to skip sending of the notification in the fib code that
actually inserts the route. Once the full route has been added, a
notification is generated with all nexthops.

ip6_route_multipath_add handles 3 use cases: new routes, route replace,
and route append. The multipath notification generated needs to be
consistent with the order of the nexthops and it should be consistent
with the order in a FIB dump which means the route with the first nexthop
needs to be used as the route reference. For the first 2 cases (new and
replace), a reference to the route used to send the notification is
obtained by saving the first route added. For the append case, the last
route added is used to loop back to its first sibling route which is
the first nexthop in the multipath route.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-04 19:58:14 -05:00
David Ahern
beb1afac51 net: ipv6: Add support to dump multipath routes via RTA_MULTIPATH attribute
IPv6 returns multipath routes as a series of individual routes making
their display and handling by userspace different and more complicated
than IPv4, putting the burden on the user to see that a route is part of
a multipath route and internally creating a multipath route if desired
(e.g., libnl does this as of commit 29b71371e764). This patch addresses
this difference, allowing multipath routes to be returned using the
RTA_MULTIPATH attribute.

The end result is that IPv6 multipath routes can be treated and displayed
in a format similar to IPv4:

    $ ip -6 ro ls vrf red
    2001:db8:1::/120 dev eth1 proto kernel metric 256  pref medium
    2001:db8:2::/120 dev eth2 proto kernel metric 256  pref medium
    2001:db8:200::/120 metric 1024
	    nexthop via 2001:db8:1::2  dev eth1 weight 1
	    nexthop via 2001:db8:2::2  dev eth2 weight 1

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-04 19:58:14 -05:00
David Ahern
1f5e29ce79 net: ipv6: add NLM_F_APPEND in notifications when applicable
IPv6 does not set the NLM_F_APPEND flag in notifications to signal that
a NEWROUTE is an append versus a new route or a replaced one. Add the
flag if the request has it.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-01 12:13:52 -05:00
Guillaume Nault
73483c1289 ipv6: report NLM_F_CREATE and NLM_F_EXCL flags in RTM_NEWROUTE events
Since commit 37a1d3611c ("ipv6: include NLM_F_REPLACE in route
replace notifications"), RTM_NEWROUTE notifications have their
NLM_F_REPLACE flag set if the new route replaced a preexisting one.
However, other flags aren't set.

This patch reports the missing NLM_F_CREATE and NLM_F_EXCL flag bits.

NLM_F_APPEND is not reported, because in ipv6 a NLM_F_CREATE request
is interpreted as an append request (contrary to ipv4, "prepend" is not
supported, so if NLM_F_EXCL is not set then NLM_F_APPEND is implicit).

As a result, the possible flag combination can now be reported
(iproute2's terminology into parentheses):

  * NLM_F_CREATE | NLM_F_EXCL: route didn't exist, exclusive creation
    ("add").
  * NLM_F_CREATE: route did already exist, new route added after
    preexisting ones ("append").
  * NLM_F_REPLACE: route did already exist, new route replaced the
    first preexisting one ("change").

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-09 16:50:23 -07:00
Martin KaFai Lau
903ce4abdf ipv6: Fix mem leak in rt6i_pcpu
It was first reported and reproduced by Petr (thanks!) in
https://bugzilla.kernel.org/show_bug.cgi?id=119581

free_percpu(rt->rt6i_pcpu) used to always happen in ip6_dst_destroy().

However, after fixing a deadlock bug in
commit 9c7370a166 ("ipv6: Fix a potential deadlock when creating pcpu rt"),
free_percpu() is not called before setting non_pcpu_rt->rt6i_pcpu to NULL.

It is worth to note that rt6i_pcpu is protected by table->tb6_lock.

kmemleak somehow did not report it.  We nailed it down by
observing the pcpu entries in /proc/vmallocinfo (first suggested
by Hannes, thanks!).

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Fixes: 9c7370a166 ("ipv6: Fix a potential deadlock when creating pcpu rt")
Reported-by: Petr Novopashenniy <pety@rusnet.ru>
Tested-by: Petr Novopashenniy <pety@rusnet.ru>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Petr Novopashenniy <pety@rusnet.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-05 14:09:23 -07:00
David Ahern
b3b4663c97 net: vrf: Create FIB tables on link create
Tables have to exist for VRFs to function. Ensure they exist
when VRF device is created.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-06 15:51:47 -04:00
Michal Kubeček
3dc94f93be ipv6: per netns FIB garbage collection
One of our customers observed issues with FIB6 garbage collectors
running in different network namespaces blocking each other, resulting
in soft lockups (fib6_run_gc() initiated from timer runs always in
forced mode).

Now that FIB6 walkers are separated per namespace, there is no more need
for instances of fib6_run_gc() in different namespaces blocking each
other. There is still a call to icmp6_dst_gc() which operates on shared
data but this function is protected by its own shared lock.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 15:16:51 -05:00
Michal Kubeček
9a03cd8f38 ipv6: per netns fib6 walkers
The IPv6 FIB data structures are separated per network namespace but
there is still only one global walkers list and one global walker list
lock. This means changes in one namespace unnecessarily interfere with
walkers in other namespaces.

Replace the global list with per-netns lists (and give each its own
lock).

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 15:16:51 -05:00
Michal Kubeček
3570df914f ipv6: replace global gc_args with local variable
Global variable gc_args is only used in fib6_run_gc() and functions
called from it. As fib6_run_gc() makes sure there is at most one
instance of fib6_clean_all() running at any moment, we can replace
gc_args with a local variable which will be needed once multiple
instances (per netns) of garbage collector are allowed.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 15:16:50 -05:00
David S. Miller
ba3e2084f2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	net/ipv6/xfrm6_output.c
	net/openvswitch/flow_netlink.c
	net/openvswitch/vport-gre.c
	net/openvswitch/vport-vxlan.c
	net/openvswitch/vport.c
	net/openvswitch/vport.h

The openvswitch conflicts were overlapping changes.  One was
the egress tunnel info fix in 'net' and the other was the
vport ->send() op simplification in 'net-next'.

The xfrm6_output.c conflicts was also a simplification
overlapping a bug fix.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-24 06:54:12 -07:00
lucien
ab997ad408 ipv6: fix the incorrect return value of throw route
The error condition -EAGAIN, which is signaled by throw routes, tells
the rules framework to walk on searching for next matches. If the walk
ends and we stop walking the rules with the result of a throw route we
have to translate the error conditions to -ENETUNREACH.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-23 02:38:18 -07:00
David Ahern
c485068778 net: Export fib6_get_table and nd_tbl
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-13 04:55:05 -07:00
Roopa Prabhu
37a1d3611c ipv6: include NLM_F_REPLACE in route replace notifications
This patch adds NLM_F_REPLACE flag to ipv6 route replace notifications.
This makes nlm_flags in ipv6 replace notifications consistent
with ipv4.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-17 15:00:27 -07:00
Martin KaFai Lau
70da5b5c53 ipv6: Replace spinlock with seqlock and rcu in ip6_tunnel
This patch uses a seqlock to ensure consistency between idst->dst and
idst->cookie.  It also makes dst freeing from fib tree to undergo a
rcu grace period.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-15 14:53:05 -07:00
Martin KaFai Lau
8e3d5be736 ipv6: Avoid double dst_free
It is a prep work to get dst freeing from fib tree undergo
a rcu grace period.

The following is a common paradigm:
if (ip6_del_rt(rt))
	dst_free(rt)

which means, if rt cannot be deleted from the fib tree, dst_free(rt) now.
1. We don't know the ip6_del_rt(rt) failure is because it
   was not managed by fib tree (e.g. DST_NOCACHE) or it had already been
   removed from the fib tree.
2. If rt had been managed by the fib tree, ip6_del_rt(rt) failure means
   dst_free(rt) has been called already.  A second
   dst_free(rt) is not always obviously safe.  The rt may have
   been destroyed already.
3. If rt is a DST_NOCACHE, dst_free(rt) should not be called.
4. It is a stopper to make dst freeing from fib tree undergo a
   rcu grace period.

This patch is to use a DST_NOCACHE flag to indicate a rt is
not managed by the fib tree.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-15 14:53:05 -07:00
David S. Miller
dc25b25897 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/usb/qmi_wwan.c

Overlapping additions of new device IDs to qmi_wwan.c

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-21 11:44:04 -07:00
Jiri Benc
61adedf3e3 route: move lwtunnel state to dst_entry
Currently, the lwtunnel state resides in per-protocol data. This is
a problem if we encapsulate ipv6 traffic in an ipv4 tunnel (or vice versa).
The xmit function of the tunnel does not know whether the packet has been
routed to it by ipv4 or ipv6, yet it needs the lwtstate data. Moving the
lwtstate data to dst_entry makes such inter-protocol tunneling possible.

As a bonus, this brings a nice diffstat.

Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-20 15:42:36 -07:00
Martin KaFai Lau
9c7370a166 ipv6: Fix a potential deadlock when creating pcpu rt
rt6_make_pcpu_route() is called under read_lock(&table->tb6_lock).
rt6_make_pcpu_route() calls ip6_rt_pcpu_alloc(rt) which then
calls dst_alloc().  dst_alloc() _may_ call ip6_dst_gc() which takes
the write_lock(&tabl->tb6_lock).  A visualized version:

read_lock(&table->tb6_lock);
rt6_make_pcpu_route();
=> ip6_rt_pcpu_alloc();
=> dst_alloc();
=> ip6_dst_gc();
=> write_lock(&table->tb6_lock); /* oops */

The fix is to do a read_unlock first before calling ip6_rt_pcpu_alloc().

A reported stack:

[141625.537638] INFO: rcu_sched self-detected stall on CPU { 27}  (t=60000 jiffies g=4159086 c=4159085 q=2139)
[141625.547469] Task dump for CPU 27:
[141625.550881] mtr             R  running task        0 22121  22081 0x00000008
[141625.558069]  0000000000000000 ffff88103f363d98 ffffffff8106e488 000000000000001b
[141625.565641]  ffffffff81684900 ffff88103f363db8 ffffffff810702b0 0000000008000000
[141625.573220]  ffffffff81684900 ffff88103f363de8 ffffffff8108df9f ffff88103f375a00
[141625.580803] Call Trace:
[141625.583345]  <IRQ>  [<ffffffff8106e488>] sched_show_task+0xc1/0xc6
[141625.589650]  [<ffffffff810702b0>] dump_cpu_task+0x35/0x39
[141625.595144]  [<ffffffff8108df9f>] rcu_dump_cpu_stacks+0x6a/0x8c
[141625.601320]  [<ffffffff81090606>] rcu_check_callbacks+0x1f6/0x5d4
[141625.607669]  [<ffffffff810940c8>] update_process_times+0x2a/0x4f
[141625.613925]  [<ffffffff8109fbee>] tick_sched_handle+0x32/0x3e
[141625.619923]  [<ffffffff8109fc2f>] tick_sched_timer+0x35/0x5c
[141625.625830]  [<ffffffff81094a1f>] __hrtimer_run_queues+0x8f/0x18d
[141625.632171]  [<ffffffff81094c9e>] hrtimer_interrupt+0xa0/0x166
[141625.638258]  [<ffffffff8102bf2a>] local_apic_timer_interrupt+0x4e/0x52
[141625.645036]  [<ffffffff8102c36f>] smp_apic_timer_interrupt+0x39/0x4a
[141625.651643]  [<ffffffff8140b9e8>] apic_timer_interrupt+0x68/0x70
[141625.657895]  <EOI>  [<ffffffff81346ee8>] ? dst_destroy+0x7c/0xb5
[141625.664188]  [<ffffffff813d45b5>] ? fib6_flush_trees+0x20/0x20
[141625.670272]  [<ffffffff81082b45>] ? queue_write_lock_slowpath+0x60/0x6f
[141625.677140]  [<ffffffff8140aa33>] _raw_write_lock_bh+0x23/0x25
[141625.683218]  [<ffffffff813d4553>] __fib6_clean_all+0x40/0x82
[141625.689124]  [<ffffffff813d45b5>] ? fib6_flush_trees+0x20/0x20
[141625.695207]  [<ffffffff813d6058>] fib6_clean_all+0xe/0x10
[141625.700854]  [<ffffffff813d60d3>] fib6_run_gc+0x79/0xc8
[141625.706329]  [<ffffffff813d0510>] ip6_dst_gc+0x85/0xf9
[141625.711718]  [<ffffffff81346d68>] dst_alloc+0x55/0x159
[141625.717105]  [<ffffffff813d09b5>] __ip6_dst_alloc.isra.32+0x19/0x63
[141625.723620]  [<ffffffff813d1830>] ip6_pol_route+0x36a/0x3e8
[141625.729441]  [<ffffffff813d18d6>] ip6_pol_route_output+0x11/0x13
[141625.735700]  [<ffffffff813f02c8>] fib6_rule_action+0xa7/0x1bf
[141625.741698]  [<ffffffff813d18c5>] ? ip6_pol_route_input+0x17/0x17
[141625.748043]  [<ffffffff81357c48>] fib_rules_lookup+0xb5/0x12a
[141625.754050]  [<ffffffff81141628>] ? poll_select_copy_remaining+0xf9/0xf9
[141625.761002]  [<ffffffff813f0535>] fib6_rule_lookup+0x37/0x5c
[141625.766914]  [<ffffffff813d18c5>] ? ip6_pol_route_input+0x17/0x17
[141625.773260]  [<ffffffff813d008c>] ip6_route_output+0x7a/0x82
[141625.779177]  [<ffffffff813c44c8>] ip6_dst_lookup_tail+0x53/0x112
[141625.785437]  [<ffffffff813c45c3>] ip6_dst_lookup_flow+0x2a/0x6b
[141625.791604]  [<ffffffff813ddaab>] rawv6_sendmsg+0x407/0x9b6
[141625.797423]  [<ffffffff813d7914>] ? do_ipv6_setsockopt.isra.8+0xd87/0xde2
[141625.804464]  [<ffffffff8139d4b4>] inet_sendmsg+0x57/0x8e
[141625.810028]  [<ffffffff81329ba3>] sock_sendmsg+0x2e/0x3c
[141625.815588]  [<ffffffff8132be57>] SyS_sendto+0xfe/0x143
[141625.821063]  [<ffffffff813dd551>] ? rawv6_setsockopt+0x5e/0x67
[141625.827146]  [<ffffffff8132c9f8>] ? sock_common_setsockopt+0xf/0x11
[141625.833660]  [<ffffffff8132c08c>] ? SyS_setsockopt+0x81/0xa2
[141625.839565]  [<ffffffff8140ac17>] entry_SYSCALL_64_fastpath+0x12/0x6a

Fixes: d52d3997f8 ("pv6: Create percpu rt6_info")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
CC: Hannes Frederic Sowa <hannes@stressinduktion.org>
Reported-by: Steinar H. Gunderson <sgunderson@bigfoot.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-17 14:28:03 -07:00
Nicolas Dichtel
5a6228a0b4 lwtunnel: change prototype of lwtunnel_state_get()
It saves some lines and simplify a bit the code when the state is returning
by this function. It's also useful to handle a NULL entry.

To avoid too long lines, I've also renamed lwtunnel_state_get() and
lwtunnel_state_put() to lwtstate_get() and lwtstate_put().

CC: Thomas Graf <tgraf@suug.ch>
CC: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-27 01:02:49 -07:00
Roopa Prabhu
19e42e4515 ipv6: support for fib route lwtunnel encap attributes
This patch adds support in ipv6 fib functions to parse Netlink
RTA encap attributes and attach encap state data to rt6_info.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21 10:39:04 -07:00
Martin KaFai Lau
d52d3997f8 ipv6: Create percpu rt6_info
After the patch
'ipv6: Only create RTF_CACHE routes after encountering pmtu exception',
we need to compensate the performance hit (bouncing dst->__refcnt).

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-25 13:25:35 -04:00
Martin KaFai Lau
45e4fd2668 ipv6: Only create RTF_CACHE routes after encountering pmtu exception
This patch creates a RTF_CACHE routes only after encountering a pmtu
exception.

After ip6_rt_update_pmtu() has inserted the RTF_CACHE route to the fib6
tree, the rt->rt6i_node->fn_sernum is bumped which will fail the
ip6_dst_check() and trigger a relookup.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-25 13:25:33 -04:00
Michal Kubeček
2759647247 ipv6: fix ECMP route replacement
When replacing an IPv6 multipath route with "ip route replace", i.e.
NLM_F_CREATE | NLM_F_REPLACE, fib6_add_rt2node() replaces only first
matching route without fixing its siblings, resulting in corrupted
siblings linked list; removing one of the siblings can then end in an
infinite loop.

IPv6 ECMP implementation is a bit different from IPv4 so that route
replacement cannot work in exactly the same way. This should be a
reasonable approximation:

1. If the new route is ECMP-able and there is a matching ECMP-able one
already, replace it and all its siblings (if any).

2. If the new route is ECMP-able and no matching ECMP-able route exists,
replace first matching non-ECMP-able (if any) or just add the new one.

3. If the new route is not ECMP-able, replace first matching
non-ECMP-able route (if any) or add the new route.

We also need to remove the NLM_F_REPLACE flag after replacing old
route(s) by first nexthop of an ECMP route so that each subsequent
nexthop does not replace previous one.

Fixes: 51ebd31815 ("ipv6: add support of equal cost multipath (ECMP)")
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-20 12:02:26 -04:00
Ian Morris
53b24b8f94 ipv6: coding style: comparison for inequality with NULL
The ipv6 code uses a mixture of coding styles. In some instances check for NULL
pointer is done as x != NULL and sometimes as x. x is preferred according to
checkpatch and this patch makes the code consistent by adopting the latter
form.

No changes detected by objdiff.

Signed-off-by: Ian Morris <ipm@chirality.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-31 13:51:54 -04:00
David S. Miller
95f873f2ff Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	arch/arm/boot/dts/imx6sx-sdb.dts
	net/sched/cls_bpf.c

Two simple sets of overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-27 16:59:56 -08:00
Hannes Frederic Sowa
6e9e16e614 ipv6: replacing a rt6_info needs to purge possible propagated rt6_infos too
Lubomir Rintel reported that during replacing a route the interface
reference counter isn't correctly decremented.

To quote bug <https://bugzilla.kernel.org/show_bug.cgi?id=91941>:
| [root@rhel7-5 lkundrak]# sh -x lal
| + ip link add dev0 type dummy
| + ip link set dev0 up
| + ip link add dev1 type dummy
| + ip link set dev1 up
| + ip addr add 2001:db8:8086::2/64 dev dev0
| + ip route add 2001:db8:8086::/48 dev dev0 proto static metric 20
| + ip route add 2001:db8:8088::/48 dev dev1 proto static metric 10
| + ip route replace 2001:db8:8086::/48 dev dev1 proto static metric 20
| + ip link del dev0 type dummy
| Message from syslogd@rhel7-5 at Jan 23 10:54:41 ...
|  kernel:unregister_netdevice: waiting for dev0 to become free. Usage count = 2
|
| Message from syslogd@rhel7-5 at Jan 23 10:54:51 ...
|  kernel:unregister_netdevice: waiting for dev0 to become free. Usage count = 2

During replacement of a rt6_info we must walk all parent nodes and check
if the to be replaced rt6_info got propagated. If so, replace it with
an alive one.

Fixes: 4a287eba2d ("IPv6 routing, NLM_F_* flag support: REPLACE and EXCL flags support, warn about missing CREATE flag")
Reported-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Tested-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-27 00:22:14 -08:00
Johannes Berg
053c095a82 netlink: make nlmsg_end() and genlmsg_end() void
Contrary to common expectations for an "int" return, these functions
return only a positive value -- if used correctly they cannot even
return 0 because the message header will necessarily be in the skb.

This makes the very common pattern of

  if (genlmsg_end(...) < 0) { ... }

be a whole bunch of dead code. Many places also simply do

  return nlmsg_end(...);

and the caller is expected to deal with it.

This also commonly (at least for me) causes errors, because it is very
common to write

  if (my_function(...))
    /* error condition */

and if my_function() does "return nlmsg_end()" this is of course wrong.

Additionally, there's not a single place in the kernel that actually
needs the message length returned, and if anyone needs it later then
it'll be very easy to just use skb->len there.

Remove this, and make the functions void. This removes a bunch of dead
code as described above. The patch adds lines because I did

-	return nlmsg_end(...);
+	nlmsg_end(...);
+	return 0;

I could have preserved all the function's return values by returning
skb->len, but instead I've audited all the places calling the affected
functions and found that none cared. A few places actually compared
the return value with <= 0 in dump functionality, but that could just
be changed to < 0 with no change in behaviour, so I opted for the more
efficient version.

One instance of the error I've made numerous times now is also present
in net/phonet/pn_netlink.c in the route_dumpit() function - it didn't
check for <0 or <=0 and thus broke out of the loop every single time.
I've preserved this since it will (I think) have caused the messages to
userspace to be formatted differently with just a single message for
every SKB returned to userspace. It's possible that this isn't needed
for the tools that actually use this, but I don't even know what they
are so couldn't test that changing this behaviour would be acceptable.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-18 01:03:45 -05:00
Florian Westphal
e715b6d3a5 net: fib6: convert cfg metric to u32 outside of table write lock
Do the nla validation earlier, outside the write lock.

This is needed by followup patch which needs to be able to call
request_module (which can sleep) if needed.

Joint work with Daniel Borkmann.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-05 22:55:24 -05:00
Daniel Borkmann
0409c9a5a7 net: fib6: fib6_commit_metrics: fix potential NULL pointer dereference
When IPv6 host routes with metrics attached are being added, we fetch
the metrics store from the dst via COW through dst_metrics_write_ptr(),
added through commit e5fd387ad5.

One remaining problem here is that we actually call into inet_getpeer()
and may end up allocating/creating a new peer from the kmemcache, which
may fail.

Example trace from perf probe (inet_getpeer:41) where create is 1:

ip 6877 [002] 4221.391591: probe:inet_getpeer: (ffffffff8165e293)
  85e294 inet_getpeer.part.7 (<- kmem_cache_alloc())
  85e578 inet_getpeer
  8eb333 ipv6_cow_metrics
  8f10ff fib6_commit_metrics

Therefore, a check for NULL on the return of dst_metrics_write_ptr()
is necessary here.

Joint work with Florian Westphal.

Fixes: e5fd387ad5 ("ipv6: do not overwrite inetpeer metrics prematurely")
Cc: Michal Kubeček <mkubecek@suse.cz>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-05 22:55:24 -05:00
Hannes Frederic Sowa
327571cb10 ipv6: don't walk node's leaf during serial number update
Cc: YOSHIFUJI Hideaki <hideaki@yoshifuji.org>
Cc: Martin Lau <kafai@fb.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-07 00:02:30 -04:00
Hannes Frederic Sowa
812918c464 ipv6: make fib6 serial number per namespace
Try to reduce number of possible fn_sernum mutation by constraining them
to their namespace.

Also remove rt_genid which I forgot to remove in 705f1c869d ("ipv6:
remove rt6i_genid").

Cc: YOSHIFUJI Hideaki <hideaki@yoshifuji.org>
Cc: Martin Lau <kafai@fb.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-07 00:02:30 -04:00
Hannes Frederic Sowa
c8c4d42a6b ipv6: only generate one new serial number per fib mutation
Cc: YOSHIFUJI Hideaki <hideaki@yoshifuji.org>
Cc: Martin Lau <kafai@fb.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-07 00:02:30 -04:00
Hannes Frederic Sowa
42b1870646 ipv6: make rt_sernum atomic and serial number fields ordinary ints
Cc: YOSHIFUJI Hideaki <hideaki@yoshifuji.org>
Cc: Martin Lau <kafai@fb.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-07 00:02:30 -04:00
Hannes Frederic Sowa
94b2cfe02b ipv6: minor fib6 cleanups like type safety, bool conversion, inline removal
Also renamed struct fib6_walker_t to fib6_walker and enum fib_walk_state_t
to fib6_walk_state as recommended by Cong Wang.

Cc: Cong Wang <cwang@twopensource.com>
Cc: YOSHIFUJI Hideaki <hideaki@yoshifuji.org>
Cc: Martin Lau <kafai@fb.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-07 00:02:30 -04:00
Hannes Frederic Sowa
705f1c869d ipv6: remove rt6i_genid
Eric Dumazet noticed that all no-nonexthop or no-gateway routes which
are already marked DST_HOST (e.g. input routes routes) will always be
invalidated during sk_dst_check. Thus per-socket dst caching absolutely
had no effect and early demuxing had no effect.

Thus this patch removes rt6i_genid: fn_sernum already gets modified during
add operations, so we only must ensure we mutate fn_sernum during ipv6
address remove operations. This is a fairly cost extensive operations,
but address removal should not happen that often. Also our mtu update
functions do the same and we heard no complains so far. xfrm policy
changes also cause a call into fib6_flush_trees. Also plug a hole in
rt6_info (no cacheline changes).

I verified via tracing that this change has effect.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: YOSHIFUJI Hideaki <hideaki@yoshifuji.org>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Cc: Martin Lau <kafai@fb.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-30 14:00:48 -04:00
Benjamin Block
793c3b4000 net: ipv6: fib: don't sleep inside atomic lock
The function fib6_commit_metrics() allocates a piece of memory in mode
GFP_KERNEL while holding an atomic lock from higher up in the stack, in
the function __ip6_ins_rt(). This produces the following BUG:

> BUG: sleeping function called from invalid context at mm/slub.c:1250
> in_atomic(): 1, irqs_disabled(): 0, pid: 2909, name: dhcpcd
> 2 locks held by dhcpcd/2909:
>  #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff81978e67>] rtnl_lock+0x17/0x20
>  #1:  (&tb->tb6_lock){++--+.}, at: [<ffffffff81a6951a>] ip6_route_add+0x65a/0x800
> CPU: 1 PID: 2909 Comm: dhcpcd Not tainted 3.17.0-rc1 #1
> Hardware name: ASUS All Series/Q87T, BIOS 0216 10/16/2013
>  0000000000000008 ffff8800c8f13858 ffffffff81af135a 0000000000000000
>  ffff880212202430 ffff8800c8f13878 ffffffff810f8d3a ffff880212202c98
>  0000000000000010 ffff8800c8f138c8 ffffffff8121ad0e 0000000000000001
> Call Trace:
>  [<ffffffff81af135a>] dump_stack+0x4e/0x68
>  [<ffffffff810f8d3a>] __might_sleep+0x10a/0x120
>  [<ffffffff8121ad0e>] kmem_cache_alloc_trace+0x4e/0x190
>  [<ffffffff81a6bcd6>] ? fib6_commit_metrics+0x66/0x110
>  [<ffffffff81a6bcd6>] fib6_commit_metrics+0x66/0x110
>  [<ffffffff81a6cbf3>] fib6_add+0x883/0xa80
>  [<ffffffff81a6951a>] ? ip6_route_add+0x65a/0x800
>  [<ffffffff81a69535>] ip6_route_add+0x675/0x800
>  [<ffffffff81a68f2a>] ? ip6_route_add+0x6a/0x800
>  [<ffffffff81a6990c>] inet6_rtm_newroute+0x5c/0x80
>  [<ffffffff8197cf01>] rtnetlink_rcv_msg+0x211/0x260
>  [<ffffffff81978e67>] ? rtnl_lock+0x17/0x20
>  [<ffffffff81119708>] ? lock_release_holdtime+0x28/0x180
>  [<ffffffff81978e67>] ? rtnl_lock+0x17/0x20
>  [<ffffffff8197ccf0>] ? __rtnl_unlock+0x20/0x20
>  [<ffffffff819a989e>] netlink_rcv_skb+0x6e/0xd0
>  [<ffffffff81978ee5>] rtnetlink_rcv+0x25/0x40
>  [<ffffffff819a8e59>] netlink_unicast+0xd9/0x180
>  [<ffffffff819a9600>] netlink_sendmsg+0x700/0x770
>  [<ffffffff81103735>] ? local_clock+0x25/0x30
>  [<ffffffff8194e83c>] sock_sendmsg+0x6c/0x90
>  [<ffffffff811f98e3>] ? might_fault+0xa3/0xb0
>  [<ffffffff8195ca6d>] ? verify_iovec+0x7d/0xf0
>  [<ffffffff8194ec3e>] ___sys_sendmsg+0x37e/0x3b0
>  [<ffffffff8111ef15>] ? trace_hardirqs_on_caller+0x185/0x220
>  [<ffffffff81af979e>] ? mutex_unlock+0xe/0x10
>  [<ffffffff819a55ec>] ? netlink_insert+0xbc/0xe0
>  [<ffffffff819a65e5>] ? netlink_autobind.isra.30+0x125/0x150
>  [<ffffffff819a6520>] ? netlink_autobind.isra.30+0x60/0x150
>  [<ffffffff819a84f9>] ? netlink_bind+0x159/0x230
>  [<ffffffff811f989a>] ? might_fault+0x5a/0xb0
>  [<ffffffff8194f25e>] ? SYSC_bind+0x7e/0xd0
>  [<ffffffff8194f8cd>] __sys_sendmsg+0x4d/0x80
>  [<ffffffff8194f912>] SyS_sendmsg+0x12/0x20
>  [<ffffffff81afc692>] system_call_fastpath+0x16/0x1b

Fixing this by replacing the mode GFP_KERNEL with GFP_ATOMIC.

Signed-off-by: Benjamin Block <bebl@mageta.org>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-22 10:54:49 -07:00
David S. Miller
5f013c9bc7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/altera/altera_sgdma.c
	net/netlink/af_netlink.c
	net/sched/cls_api.c
	net/sched/sch_api.c

The netlink conflict dealt with moving to netlink_capable() and
netlink_ns_capable() in the 'net' tree vs. supporting 'tc' operations
in non-init namespaces.  These were simple transformations from
netlink_capable to netlink_ns_capable.

The Altera driver conflict was simply code removal overlapping some
void pointer cast cleanups in net-next.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-12 13:19:14 -04:00
Duan Jiong
163cd4e817 ipv6: remove parameter rt from fib6_prune_clones()
the parameter rt will be assigned to c.arg in function fib6_clean_tree(),
but function fib6_prune_clone() doesn't use c.arg, so we can remove it
safely.

Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-12 01:06:42 -04:00
Kumar Sundararajan
1c26585458 ipv6: fib: fix fib dump restart
When the ipv6 fib changes during a table dump, the walk is
restarted and the number of nodes dumped are skipped. But the existing
code doesn't advance to the next node after a node is skipped. This can
cause the dump to loop or produce lots of duplicates when the fib
is modified during the dump.

This change advances the walk to the next node if the current node is
skipped after a restart.

Signed-off-by: Kumar Sundararajan <kumar@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-24 17:19:25 -04:00
Wang Yufen
437de07ced ipv6: fix checkpatch errors of "foo*" and "foo * bar"
ERROR: "(foo*)" should be "(foo *)"
ERROR: "foo * bar" should be "foo *bar"

Suggested-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Acked-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-29 18:15:52 -04:00
Wang Yufen
49e253e399 ipv6: fix checkpatch errors of brace and trailing statements
ERROR: open brace '{' following enum go on the same line
ERROR: open brace '{' following struct go on the same line
ERROR: trailing statements should be on next line

Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-29 18:15:52 -04:00
Wang Yufen
8db46f1d4c ipv6: fix checkpatch errors comments and space
WARNING: please, no space before tabs
WARNING: please, no spaces at the start of a line
ERROR: spaces required around that ':' (ctx:VxW)
ERROR: spaces required around that '>' (ctx:VxV)
ERROR: spaces required around that '>=' (ctx:VxV)

Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-29 18:15:52 -04:00
Michal Kubeček
e5fd387ad5 ipv6: do not overwrite inetpeer metrics prematurely
If an IPv6 host route with metrics exists, an attempt to add a
new route for the same target with different metrics fails but
rewrites the metrics anyway:

12sp0:~ # ip route add fec0::1 dev eth0 rto_min 1000
12sp0:~ # ip -6 route show
fe80::/64 dev eth0  proto kernel  metric 256
fec0::1 dev eth0  metric 1024  rto_min lock 1s
12sp0:~ # ip route add fec0::1 dev eth0 rto_min 1500
RTNETLINK answers: File exists
12sp0:~ # ip -6 route show
fe80::/64 dev eth0  proto kernel  metric 256
fec0::1 dev eth0  metric 1024  rto_min lock 1.5s

This is caused by all IPv6 host routes using the metrics in
their inetpeer (or the shared default). This also holds for the
new route created in ip6_route_add() which shares the metrics
with the already existing route and thus ip6_route_add()
rewrites the metrics even if the new route ends up not being
used at all.

Another problem is that old metrics in inetpeer can reappear
unexpectedly for a new route, e.g.

12sp0:~ # ip route add fec0::1 dev eth0 rto_min 1000
12sp0:~ # ip route del fec0::1
12sp0:~ # ip route add fec0::1 dev eth0
12sp0:~ # ip route change fec0::1 dev eth0 hoplimit 10
12sp0:~ # ip -6 route show
fe80::/64 dev eth0  proto kernel  metric 256
fec0::1 dev eth0  metric 1024  hoplimit 10 rto_min lock 1s

Resolve the first problem by moving the setting of metrics down
into fib6_add_rt2node() to the point we are sure we are
inserting the new route into the tree. Second problem is
addressed by introducing new flag DST_METRICS_FORCE_OVERWRITE
which is set for a new host route in ip6_route_add() and makes
ipv6_cow_metrics() always overwrite the metrics in inetpeer
(even if they are not "new"); it is reset after that.

v5: use a flag in _metrics member rather than one in flags

v4: fix a typo making a condition always true (thanks to Hannes
Frederic Sowa)

v3: rewritten based on David Miller's idea to move setting the
metrics (and allocation in non-host case) down to the point we
already know the route is to be inserted. Also rebased to
net-next as it is quite late in the cycle.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-27 15:09:07 -04:00
Li RongQing
0c3584d589 ipv6: remove prune parameter for fib6_clean_all
since the prune parameter for fib6_clean_all always is 0, remove it.

Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-02 03:30:35 -05:00
Hannes Frederic Sowa
0a67d3efa4 ipv6: compare sernum when walking fib for /proc/net/ipv6_route as safety net
This patch provides an additional safety net against NULL
pointer dereferences while walking the fib trie for the new
/proc/net/ipv6_route walkers. I never needed it myself and am unsure
if it is needed at all, but the same checks where introduced in
2bec5a369e ("ipv6: fib: fix crash when
changing large fib while dumping it") to fix NULL pointer bugs.

This patch is separated from the first patch to make it easier to revert
if we are sure we can drop this logic.

Cc: Ben Greear <greearb@candelatech.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-27 17:32:17 -04:00
Hannes Frederic Sowa
8d2ca1d7b5 ipv6: avoid high order memory allocations for /proc/net/ipv6_route
Dumping routes on a system with lots rt6_infos in the fibs causes up to
11-order allocations in seq_file (which fail). While we could switch
there to vmalloc we could just implement the streaming interface for
/proc/net/ipv6_route. This patch switches /proc/net/ipv6_route from
single_open_net to seq_open_net.

loff_t *pos tracks dst entries.

Also kill never used struct rt6_proc_arg and now unused function
fib6_clean_all_ro.

Cc: Ben Greear <greearb@candelatech.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-27 17:32:16 -04:00
Daniel Borkmann
ae7b4e1f21 net: fib: fib6_add: fix potential NULL pointer dereference
When the kernel is compiled with CONFIG_IPV6_SUBTREES, and we return
with an error in fn = fib6_add_1(), then error codes are encoded into
the return pointer e.g. ERR_PTR(-ENOENT). In such an error case, we
write the error code into err and jump to out, hence enter the if(err)
condition. Now, if CONFIG_IPV6_SUBTREES is enabled, we check for:

  if (pn != fn && pn->leaf == rt)
    ...
  if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO))
    ...

Since pn is NULL and fn is f.e. ERR_PTR(-ENOENT), then pn != fn
evaluates to true and causes a NULL-pointer dereference on further
checks on pn. Fix it, by setting both NULL in error case, so that
pn != fn already evaluates to false and no further dereference
takes place.

This was first correctly implemented in 4a287eba2 ("IPv6 routing,
NLM_F_* flag support: REPLACE and EXCL flags support, warn about
missing CREATE flag"), but the bug got later on introduced by
188c517a0 ("ipv6: return errno pointers consistently for fib6_add_1()").

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Lin Ming <mlin@ss.pku.edu.cn>
Cc: Matti Vaittinen <matti.vaittinen@nsn.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Matti Vaittinen <matti.vaittinen@nsn.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-11 16:09:59 -04:00