linux-stable.git/net/ipv6, branch v3.16.40

tcp: take care of truncations done by sk_filter()

2017-02-23T03:54:46+00:00

commit ac6e780070e30e4c35bd395acfe9191e6268bdd3 upstream.

With syzkaller help, Marco Grassi found a bug in TCP stack,
crashing in tcp_collapse()

Root cause is that sk_filter() can truncate the incoming skb,
but TCP stack was not really expecting this to happen.
It probably was expecting a simple DROP or ACCEPT behavior.

We first need to make sure no part of TCP header could be removed.
Then we need to adjust TCP_SKB_CB(skb)->end_seq

Many thanks to syzkaller team and Marco for giving us a reproducer.

Signed-off-by: Eric Dumazet 
Reported-by: Marco Grassi 
Reported-by: Vladis Dronov 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

ipv6: Set skb->protocol properly for local output

2017-02-23T03:54:41+00:00

commit b4e479a96fc398ccf83bb1cffb4ffef8631beaf1 upstream.

When xfrm is applied to TSO/GSO packets, it follows this path:

    xfrm_output() -> xfrm_output_gso() -> skb_gso_segment()

where skb_gso_segment() relies on skb->protocol to function properly.

This patch sets skb->protocol to ETH_P_IPV6 before dst_output() is called,
fixing a bug where GSO packets sent through an ipip6 tunnel are dropped
when xfrm is involved.

Signed-off-by: Eli Cooper 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

ipv6: Don't use ufo handling on later transformed packets

2017-02-23T03:54:26+00:00

commit f89c56ce710afa65e1b2ead555b52c4807f34ff7 upstream.

Similar to commit c146066ab802 ("ipv4: Don't use ufo handling on later
transformed packets"), don't perform UFO on packets that will be IPsec
transformed. To detect it we rely on the fact that headerlen in
dst_entry is non-zero only for transformation bundles (xfrm_dst
objects).

Unwanted segmentation can be observed with a NETIF_F_UFO capable device,
such as a dummy device:

  DEV=dum0 LEN=1493

  ip li add $DEV type dummy
  ip addr add fc00::1/64 dev $DEV nodad
  ip link set $DEV up
  ip xfrm policy add dir out src fc00::1 dst fc00::2 \
     tmpl src fc00::1 dst fc00::2 proto esp spi 1
  ip xfrm state add src fc00::1 dst fc00::2 \
     proto esp spi 1 enc 'aes' 0x0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b

  tcpdump -n -nn -i $DEV -t &
  socat /dev/zero,readbytes=$LEN udp6:[fc00::2]:$LEN

tcpdump output before:

  IP6 fc00::1 > fc00::2: frag (0|1448) ESP(spi=0x00000001,seq=0x1), length 1448
  IP6 fc00::1 > fc00::2: frag (1448|48)
  IP6 fc00::1 > fc00::2: ESP(spi=0x00000001,seq=0x2), length 88

... and after:

  IP6 fc00::1 > fc00::2: frag (0|1448) ESP(spi=0x00000001,seq=0x1), length 1448
  IP6 fc00::1 > fc00::2: frag (1448|80)

Fixes: e89e9cf539a2 ("[IPv4/IPv6]: UFO Scatter-gather approach")

Signed-off-by: Jakub Sitnicki 
Acked-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

ipv6: correctly add local routes when lo goes up

2017-02-23T03:54:15+00:00

commit a220445f9f4382c36a53d8ef3e08165fa27f7e2c upstream.

The goal of the patch is to fix this scenario:
 ip link add dummy1 type dummy
 ip link set dummy1 up
 ip link set lo down ; ip link set lo up

After that sequence, the local route to the link layer address of dummy1 is
not there anymore.

When the loopback is set down, all local routes are deleted by
addrconf_ifdown()/rt6_ifdown(). At this time, the rt6_info entry still
exists, because the corresponding idev has a reference on it. After the rcu
grace period, dst_rcu_free() is called, and thus ___dst_free(), which will
set obsolete to DST_OBSOLETE_DEAD.

In this case, init_loopback() is called before dst_rcu_free(), thus
obsolete is still sets to something <= 0. So, the function doesn't add the
route again. To avoid that race, let's check the rt6 refcnt instead.

Fixes: 25fb6ca4ed9c ("net IPv6 : Fix broken IPv6 routing table after loopback down-up")
Fixes: a881ae1f625c ("ipv6: don't call addrconf_dst_alloc again when enable lo")
Fixes: 33d99113b110 ("ipv6: reallocate addrconf router for ipv6 address when lo device up")
Reported-by: Francesco Santoro 
Reported-by: Samuel Gauthier 
CC: Balakumaran Kannan 
CC: Maruthi Thotad 
CC: Sabrina Dubroca 
CC: Hannes Frederic Sowa 
CC: Weilong Chen 
CC: Gao feng 
Signed-off-by: Nicolas Dichtel 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

ipmr, ip6mr: fix scheduling while atomic and a deadlock with ipmr_get_route

2016-11-20T01:17:35+00:00

commit 2cf750704bb6d7ed8c7d732e071dd1bc890ea5e8 upstream.

Since the commit below the ipmr/ip6mr rtnl_unicast() code uses the portid
instead of the previous dst_pid which was copied from in_skb's portid.
Since the skb is new the portid is 0 at that point so the packets are sent
to the kernel and we get scheduling while atomic or a deadlock (depending
on where it happens) by trying to acquire rtnl two times.
Also since this is RTM_GETROUTE, it can be triggered by a normal user.

Here's the sleeping while atomic trace:
[ 7858.212557] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
[ 7858.212748] in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/0
[ 7858.212881] 2 locks held by swapper/0/0:
[ 7858.213013]  #0:  (((&mrt->ipmr_expire_timer))){+.-...}, at: [] call_timer_fn+0x5/0x350
[ 7858.213422]  #1:  (mfc_unres_lock){+.....}, at: [] ipmr_expire_process+0x25/0x130
[ 7858.213807] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.8.0-rc7+ #179
[ 7858.213934] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
[ 7858.214108]  0000000000000000 ffff88005b403c50 ffffffff813a7804 0000000000000000
[ 7858.214412]  ffffffff81a1338e ffff88005b403c78 ffffffff810a4a72 ffffffff81a1338e
[ 7858.214716]  000000000000026c 0000000000000000 ffff88005b403ca8 ffffffff810a4b9f
[ 7858.215251] Call Trace:
[ 7858.215412]    [] dump_stack+0x85/0xc1
[ 7858.215662]  [] ___might_sleep+0x192/0x250
[ 7858.215868]  [] __might_sleep+0x6f/0x100
[ 7858.216072]  [] mutex_lock_nested+0x33/0x4d0
[ 7858.216279]  [] ? netlink_lookup+0x25f/0x460
[ 7858.216487]  [] rtnetlink_rcv+0x1b/0x40
[ 7858.216687]  [] netlink_unicast+0x19c/0x260
[ 7858.216900]  [] rtnl_unicast+0x20/0x30
[ 7858.217128]  [] ipmr_destroy_unres+0xa9/0xf0
[ 7858.217351]  [] ipmr_expire_process+0x8f/0x130
[ 7858.217581]  [] ? ipmr_net_init+0x180/0x180
[ 7858.217785]  [] ? ipmr_net_init+0x180/0x180
[ 7858.217990]  [] call_timer_fn+0xa5/0x350
[ 7858.218192]  [] ? call_timer_fn+0x5/0x350
[ 7858.218415]  [] ? ipmr_net_init+0x180/0x180
[ 7858.218656]  [] run_timer_softirq+0x260/0x640
[ 7858.218865]  [] ? __do_softirq+0xbb/0x54f
[ 7858.219068]  [] __do_softirq+0xe8/0x54f
[ 7858.219269]  [] irq_exit+0xb8/0xc0
[ 7858.219463]  [] smp_apic_timer_interrupt+0x42/0x50
[ 7858.219678]  [] apic_timer_interrupt+0x8c/0xa0
[ 7858.219897]    [] ? native_safe_halt+0x6/0x10
[ 7858.220165]  [] ? trace_hardirqs_on+0xd/0x10
[ 7858.220373]  [] default_idle+0x23/0x190
[ 7858.220574]  [] arch_cpu_idle+0xf/0x20
[ 7858.220790]  [] default_idle_call+0x4c/0x60
[ 7858.221016]  [] cpu_startup_entry+0x39b/0x4d0
[ 7858.221257]  [] rest_init+0x135/0x140
[ 7858.221469]  [] start_kernel+0x50e/0x51b
[ 7858.221670]  [] ? early_idt_handler_array+0x120/0x120
[ 7858.221894]  [] x86_64_start_reservations+0x2a/0x2c
[ 7858.222113]  [] x86_64_start_kernel+0x13b/0x14a

Fixes: 2942e9005056 ("[RTNETLINK]: Use rtnl_unicast() for rtnetlink unicasts")
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

ip6_gre: fix flowi6_proto value in ip6gre_xmit_other()

2016-11-20T01:17:35+00:00

commit db32e4e49ce2b0e5fcc17803d011a401c0a637f6 upstream.

Similar to commit 3be07244b733 ("ip6_gre: fix flowi6_proto value in
xmit path"), set flowi6_proto to IPPROTO_GRE for output route lookup.

Up until now, ip6gre_xmit_other() has set flowi6_proto to a bogus value.
This affected output route lookup for packets sent on an ip6gretap device
in cases where routing was dependent on the value of flowi6_proto.

Since the correct proto is already set in the tunnel flowi6 template via
commit 252f3f5a1189 ("ip6_gre: Set flowi6_proto as IPPROTO_GRE in xmit
path."), simply delete the line setting the incorrect flowi6_proto value.

Suggested-by: Jiri Benc 
Fixes: c12b395a4664 ("gre: Support GRE over IPv6")
Reviewed-by: Shmulik Ladkani 
Signed-off-by: Lance Richardson 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

ip6_gre: Set flowi6_proto as IPPROTO_GRE in xmit path.

2016-11-20T01:17:35+00:00

commit 252f3f5a1189a7f6c309d8e4ff1c4c1888a27f13 upstream.

In gre6 xmit path, we are sending a GRE packet, so set fl6 proto
to IPPROTO_GRE properly.

Signed-off-by: Haishuang Yan 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

ipv6: addrconf: fix dev refcont leak when DAD failed

2016-11-20T01:17:23+00:00

commit 751eb6b6042a596b0080967c1a529a9fe98dac1d upstream.

In general, when DAD detected IPv6 duplicate address, ifp->state
will be set to INET6_IFADDR_STATE_ERRDAD and DAD is stopped by a
delayed work, the call tree should be like this:

ndisc_recv_ns
  -> addrconf_dad_failure        <- missing ifp put
     -> addrconf_mod_dad_work
       -> schedule addrconf_dad_work()
         -> addrconf_dad_stop()  <- missing ifp hold before call it

addrconf_dad_failure() called with ifp refcont holding but not put.
addrconf_dad_work() call addrconf_dad_stop() without extra holding
refcount. This will not cause any issue normally.

But the race between addrconf_dad_failure() and addrconf_dad_work()
may cause ifp refcount leak and netdevice can not be unregister,
dmesg show the following messages:

IPv6: eth0: IPv6 duplicate address fe80::XX:XXXX:XXXX:XX detected!
...
unregister_netdevice: waiting for eth0 to become free. Usage count = 1

Fixes: c15b1ccadb32 ("ipv6: move DAD and addrconf_verify processing
to workqueue")
Signed-off-by: Wei Yongjun 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

ipv6: add missing netconf notif when 'all' is updated

2016-11-20T01:17:21+00:00

commit d26c638c16cb54f6fb1507e27df93ede692db572 upstream.

The 'default' value was not advertised.

Fixes: f3a1bfb11ccb ("rtnl/ipv6: use netconf msg to advertise forwarding status")
Signed-off-by: Nicolas Dichtel 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

netfilter: x_tables: speed up jump target validation

2016-11-20T01:16:53+00:00

commit f4dc77713f8016d2e8a3295e1c9c53a21f296def upstream.

The dummy ruleset I used to test the original validation change was broken,
most rules were unreachable and were not tested by mark_source_chains().

In some cases rulesets that used to load in a few seconds now require
several minutes.

sample ruleset that shows the behaviour:

echo "*filter"
for i in $(seq 0 100000);do
        printf ":chain_%06x - [0:0]\n" $i
done
for i in $(seq 0 100000);do
   printf -- "-A INPUT -j chain_%06x\n" $i
   printf -- "-A INPUT -j chain_%06x\n" $i
   printf -- "-A INPUT -j chain_%06x\n" $i
done
echo COMMIT

[ pipe result into iptables-restore ]

This ruleset will be about 74mbyte in size, with ~500k searches
though all 500k[1] rule entries. iptables-restore will take forever
(gave up after 10 minutes)

Instead of always searching the entire blob for a match, fill an
array with the start offsets of every single ipt_entry struct,
then do a binary search to check if the jump target is present or not.

After this change ruleset restore times get again close to what one
gets when reverting 36472341017529e (~3 seconds on my workstation).

[1] every user-defined rule gets an implicit RETURN, so we get
300k jumps + 100k userchains + 100k returns -> 500k rule entries

Fixes: 36472341017529e ("netfilter: x_tables: validate targets of jumps")
Reported-by: Jeff Wu 
Tested-by: Jeff Wu 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Florian Westphal 
Signed-off-by: Sasha Levin 
[carnil: backport to 3.16, adjust context]
Signed-off-by: Ben Hutchings