linux.git/net/ipv6, branch v4.16

net/ipv6: Fix route leaking between VRFs

2018-03-30T18:23:59+00:00

Donald reported that IPv6 route leaking between VRFs is not working.
The root cause is the strict argument in the call to rt6_lookup when
validating the nexthop spec.

ip6_route_check_nh validates the gateway and device (if given) of a
route spec. It in turn could call rt6_lookup (e.g., lookup in a given
table did not succeed so it falls back to a full lookup) and if so
sets the strict argument to 1. That means if the egress device is given,
the route lookup needs to return a result with the same device. This
strict requirement does not work with VRFs (IPv4 or IPv6) because the
oif in the flow struct is overridden with the index of the VRF device
to trigger a match on the l3mdev rule and force the lookup to its table.

The right long term solution is to add an l3mdev index to the flow
struct such that the oif is not overridden. That solution will not
backport well, so this patch aims for a simpler solution to relax the
strict argument if the route spec device is an l3mdev slave. As done
in other places, use the FLOWI_FLAG_SKIP_NH_OIF to know that the
RT6_LOOKUP_F_IFACE flag needs to be removed.

Fixes: ca254490c8df ("net: Add VRF support to IPv6 stack")
Reported-by: Donald Sharp 
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

ipv6: sr: fix seg6 encap performances with TSO enabled

2018-03-30T18:14:33+00:00

Enabling TSO can lead to abysmal performances when using seg6 in
encap mode, such as with the ixgbe driver. This patch adds a call to
iptunnel_handle_offloads() to remove the encapsulation bit if needed.

Before:
root@comp4-seg6bpf:~# iperf3 -c fc00::55
Connecting to host fc00::55, port 5201
[  4] local fc45::4 port 36592 connected to fc00::55 port 5201
[ ID] Interval           Transfer     Bandwidth       Retr  Cwnd
[  4]   0.00-1.00   sec   196 KBytes  1.60 Mbits/sec   47   6.66 KBytes
[  4]   1.00-2.00   sec   304 KBytes  2.49 Mbits/sec  100   5.33 KBytes
[  4]   2.00-3.00   sec   284 KBytes  2.32 Mbits/sec   92   5.33 KBytes

After:
root@comp4-seg6bpf:~# iperf3 -c fc00::55
Connecting to host fc00::55, port 5201
[  4] local fc45::4 port 43062 connected to fc00::55 port 5201
[ ID] Interval           Transfer     Bandwidth       Retr  Cwnd
[  4]   0.00-1.00   sec  1.03 GBytes  8.89 Gbits/sec    0    743 KBytes
[  4]   1.00-2.00   sec  1.03 GBytes  8.87 Gbits/sec    0    743 KBytes
[  4]   2.00-3.00   sec  1.03 GBytes  8.87 Gbits/sec    0    743 KBytes

Reported-by: Tom Herbert 
Fixes: 6c8702c60b88 ("ipv6: sr: add support for SRH encapsulation and injection with lwtunnels")
Signed-off-by: David Lebrun 
Signed-off-by: David S. Miller

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

2018-03-29T14:12:47+00:00

Steffen Klassert says:

====================
pull request (net): ipsec 2018-03-29

1) Fix a rcu_read_lock/rcu_read_unlock imbalance
   in the error path of xfrm_local_error().
   From Taehee Yoo.

2) Some VTI MTU fixes. From Stefano Brivio.

3) Fix a too early overwritten skb control buffer
   on xfrm transport mode.

Please note that this pull request has a merge conflict
in net/ipv4/ip_tunnel.c.

The conflict is between

commit f6cc9c054e77 ("ip_tunnel: Emit events for post-register MTU changes")

from the net tree and

commit 24fc79798b8d ("ip_tunnel: Clamp MTU to bounds on new link")

from the ipsec tree.

It can be solved as it is currently done in linux-next.
====================

Signed-off-by: David S. Miller

ipv6: the entire IPv6 header chain must fit the first fragment

2018-03-26T01:17:20+00:00

While building ipv6 datagram we currently allow arbitrary large
extheaders, even beyond pmtu size. The syzbot has found a way
to exploit the above to trigger the following splat:

kernel BUG at ./include/linux/skbuff.h:2073!
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
    (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 4230 Comm: syzkaller672661 Not tainted 4.16.0-rc2+ #326
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:__skb_pull include/linux/skbuff.h:2073 [inline]
RIP: 0010:__ip6_make_skb+0x1ac8/0x2190 net/ipv6/ip6_output.c:1636
RSP: 0018:ffff8801bc18f0f0 EFLAGS: 00010293
RAX: ffff8801b17400c0 RBX: 0000000000000738 RCX: ffffffff84f01828
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8801b415ac18
RBP: ffff8801bc18f360 R08: ffff8801b4576844 R09: 0000000000000000
R10: ffff8801bc18f380 R11: ffffed00367aee4e R12: 00000000000000d6
R13: ffff8801b415a740 R14: dffffc0000000000 R15: ffff8801b45767c0
FS:  0000000001535880(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002000b000 CR3: 00000001b4123001 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  ip6_finish_skb include/net/ipv6.h:969 [inline]
  udp_v6_push_pending_frames+0x269/0x3b0 net/ipv6/udp.c:1073
  udpv6_sendmsg+0x2a96/0x3400 net/ipv6/udp.c:1343
  inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:764
  sock_sendmsg_nosec net/socket.c:630 [inline]
  sock_sendmsg+0xca/0x110 net/socket.c:640
  ___sys_sendmsg+0x320/0x8b0 net/socket.c:2046
  __sys_sendmmsg+0x1ee/0x620 net/socket.c:2136
  SYSC_sendmmsg net/socket.c:2167 [inline]
  SyS_sendmmsg+0x35/0x60 net/socket.c:2162
  do_syscall_64+0x280/0x940 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4404c9
RSP: 002b:00007ffdce35f948 EFLAGS: 00000217 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004404c9
RDX: 0000000000000003 RSI: 0000000020001f00 RDI: 0000000000000003
RBP: 00000000006cb018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 0000000020000080 R11: 0000000000000217 R12: 0000000000401df0
R13: 0000000000401e80 R14: 0000000000000000 R15: 0000000000000000
Code: ff e8 1d 5e b9 fc e9 15 e9 ff ff e8 13 5e b9 fc e9 44 e8 ff ff e8 29
5e b9 fc e9 c0 e6 ff ff e8 3f f3 80 fc 0f 0b e8 38 f3 80 fc <0f> 0b 49 8d
87 80 00 00 00 4d 8d 87 84 00 00 00 48 89 85 20 fe
RIP: __skb_pull include/linux/skbuff.h:2073 [inline] RSP: ffff8801bc18f0f0
RIP: __ip6_make_skb+0x1ac8/0x2190 net/ipv6/ip6_output.c:1636 RSP:
ffff8801bc18f0f0

As stated by RFC 7112 section 5:

   When a host fragments an IPv6 datagram, it MUST include the entire
   IPv6 Header Chain in the First Fragment.

So this patch addresses the issue dropping datagrams with excessive
extheader length. It also updates the error path to report to the
calling socket nonnegative pmtu values.

The issue apparently predates git history.

v1 -> v2: cleanup error path, as per Eric's suggestion

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot+91e6f9932ff122fa4410@syzkaller.appspotmail.com
Signed-off-by: Paolo Abeni 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller

net/ipv4: disable SMC TCP option with SYN Cookies

2018-03-26T00:53:54+00:00

Currently, the SMC experimental TCP option in a SYN packet is lost on
the server side when SYN Cookies are active. However, the corresponding
SYNACK sent back to the client contains the SMC option. This causes an
inconsistent view of the SMC capabilities on the client and server.

This patch disables the SMC option in the SYNACK when SYN Cookies are
active to avoid this issue.

Fixes: 60e2a7780793b ("tcp: TCP experimental option for SMC")
Signed-off-by: Hans Wippel 
Signed-off-by: Ursula Braun 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf

2018-03-24T21:10:01+00:00

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for your net tree,
they are:

1) Don't pick fixed hash implementation for NFT_SET_EVAL sets, otherwise
   userspace hits EOPNOTSUPP with valid rules using the meter statement,
   from Florian Westphal.

2) If you send a batch that flushes the existing ruleset (that contains
   a NAT chain) and the new ruleset definition comes with a new NAT
   chain, don't bogusly hit EBUSY. Also from Florian.

3) Missing netlink policy attribute validation, from Florian.

4) Detach conntrack template from skbuff if IP_NODEFRAG is set on,
   from Paolo Abeni.

5) Cache device names in flowtable object, otherwise we may end up
   walking over devices going aways given no rtnl_lock is held.

6) Fix incorrect net_device ingress with ingress hooks.

7) Fix crash when trying to read more data than available in UDP
   packets from the nf_socket infrastructure, from Subash.
====================

Signed-off-by: David S. Miller

netfilter: nf_socket: Fix out of bounds access in nf_sk_lookup_slow_v{4,6}

2018-03-24T20:17:14+00:00

skb_header_pointer will copy data into a buffer if data is non linear,
otherwise it will return a pointer in the linear section of the data.
nf_sk_lookup_slow_v{4,6} always copies data of size udphdr but later
accesses memory within the size of tcphdr (th->doff) in case of TCP
packets. This causes a crash when running with KASAN with the following
call stack -

BUG: KASAN: stack-out-of-bounds in xt_socket_lookup_slow_v4+0x524/0x718
net/netfilter/xt_socket.c:178
Read of size 2 at addr ffffffe3d417a87c by task syz-executor/28971
CPU: 2 PID: 28971 Comm: syz-executor Tainted: G    B   W  O    4.9.65+ #1
Call trace:
[] dump_backtrace+0x0/0x428 arch/arm64/kernel/traps.c:76
[] show_stack+0x28/0x38 arch/arm64/kernel/traps.c:226
[] __dump_stack lib/dump_stack.c:15 [inline]
[] dump_stack+0xd4/0x124 lib/dump_stack.c:51
[] print_address_description+0x68/0x258 mm/kasan/report.c:248
[] kasan_report_error mm/kasan/report.c:347 [inline]
[] kasan_report.part.2+0x228/0x2f0 mm/kasan/report.c:371
[] kasan_report+0x5c/0x70 mm/kasan/report.c:372
[] check_memory_region_inline mm/kasan/kasan.c:308 [inline]
[] __asan_load2+0x84/0x98 mm/kasan/kasan.c:739
[] __tcp_hdrlen include/linux/tcp.h:35 [inline]
[] xt_socket_lookup_slow_v4+0x524/0x718 net/netfilter/xt_socket.c:178

Fix this by copying data into appropriate size headers based on protocol.

Fixes: a583636a83ea ("inet: refactor inet[6]_lookup functions to take skb")
Signed-off-by: Tejaswi Tanikella 
Signed-off-by: Subash Abhinov Kasiviswanathan 
Signed-off-by: Pablo Neira Ayuso

ipv6: fix possible deadlock in rt6_age_examine_exception()

2018-03-23T17:40:34+00:00

syzbot reported a LOCKDEP splat [1] in rt6_age_examine_exception()

rt6_age_examine_exception() is called while rt6_exception_lock is held.
This lock is the lower one in the lock hierarchy, thus we can not
call dst_neigh_lookup() function, as it can fallback to neigh_create()

We should instead do a pure RCU lookup. As a bonus we avoid
a pair of atomic operations on neigh refcount.

[1]

WARNING: possible circular locking dependency detected
4.16.0-rc4+ #277 Not tainted

syz-executor7/4015 is trying to acquire lock:
 (&ndev->lock){++--}, at: [<00000000416dce19>] __ipv6_dev_mc_dec+0x45/0x350 net/ipv6/mcast.c:928

but task is already holding lock:
 (&tbl->lock){++-.}, at: [<00000000b5cb1d65>] neigh_ifdown+0x3d/0x250 net/core/neighbour.c:292

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #3 (&tbl->lock){++-.}:
       __raw_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline]
       _raw_write_lock_bh+0x31/0x40 kernel/locking/spinlock.c:312
       __neigh_create+0x87e/0x1d90 net/core/neighbour.c:528
       neigh_create include/net/neighbour.h:315 [inline]
       ip6_neigh_lookup+0x9a7/0xba0 net/ipv6/route.c:228
       dst_neigh_lookup include/net/dst.h:405 [inline]
       rt6_age_examine_exception net/ipv6/route.c:1609 [inline]
       rt6_age_exceptions+0x381/0x660 net/ipv6/route.c:1645
       fib6_age+0xfb/0x140 net/ipv6/ip6_fib.c:2033
       fib6_clean_node+0x389/0x580 net/ipv6/ip6_fib.c:1919
       fib6_walk_continue+0x46c/0x8a0 net/ipv6/ip6_fib.c:1845
       fib6_walk+0x91/0xf0 net/ipv6/ip6_fib.c:1893
       fib6_clean_tree+0x1e6/0x340 net/ipv6/ip6_fib.c:1970
       __fib6_clean_all+0x1f4/0x3a0 net/ipv6/ip6_fib.c:1986
       fib6_clean_all net/ipv6/ip6_fib.c:1997 [inline]
       fib6_run_gc+0x16b/0x3c0 net/ipv6/ip6_fib.c:2053
       ndisc_netdev_event+0x3c2/0x4a0 net/ipv6/ndisc.c:1781
       notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93
       __raw_notifier_call_chain kernel/notifier.c:394 [inline]
       raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
       call_netdevice_notifiers_info+0x32/0x70 net/core/dev.c:1707
       call_netdevice_notifiers net/core/dev.c:1725 [inline]
       __dev_notify_flags+0x262/0x430 net/core/dev.c:6960
       dev_change_flags+0xf5/0x140 net/core/dev.c:6994
       devinet_ioctl+0x126a/0x1ac0 net/ipv4/devinet.c:1080
       inet_ioctl+0x184/0x310 net/ipv4/af_inet.c:919
       sock_do_ioctl+0xef/0x390 net/socket.c:957
       sock_ioctl+0x36b/0x610 net/socket.c:1081
       vfs_ioctl fs/ioctl.c:46 [inline]
       do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686
       SYSC_ioctl fs/ioctl.c:701 [inline]
       SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
       do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
       entry_SYSCALL_64_after_hwframe+0x42/0xb7

-> #2 (rt6_exception_lock){+.-.}:
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
       _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168
       spin_lock_bh include/linux/spinlock.h:315 [inline]
       rt6_flush_exceptions+0x21/0x210 net/ipv6/route.c:1367
       fib6_del_route net/ipv6/ip6_fib.c:1677 [inline]
       fib6_del+0x624/0x12c0 net/ipv6/ip6_fib.c:1761
       __ip6_del_rt+0xc7/0x120 net/ipv6/route.c:2980
       ip6_del_rt+0x132/0x1a0 net/ipv6/route.c:2993
       __ipv6_dev_ac_dec+0x3b1/0x600 net/ipv6/anycast.c:332
       ipv6_dev_ac_dec net/ipv6/anycast.c:345 [inline]
       ipv6_sock_ac_close+0x2b4/0x3e0 net/ipv6/anycast.c:200
       inet6_release+0x48/0x70 net/ipv6/af_inet6.c:433
       sock_release+0x8d/0x1e0 net/socket.c:594
       sock_close+0x16/0x20 net/socket.c:1149
       __fput+0x327/0x7e0 fs/file_table.c:209
       ____fput+0x15/0x20 fs/file_table.c:243
       task_work_run+0x199/0x270 kernel/task_work.c:113
       exit_task_work include/linux/task_work.h:22 [inline]
       do_exit+0x9bb/0x1ad0 kernel/exit.c:865
       do_group_exit+0x149/0x400 kernel/exit.c:968
       get_signal+0x73a/0x16d0 kernel/signal.c:2469
       do_signal+0x90/0x1e90 arch/x86/kernel/signal.c:809
       exit_to_usermode_loop+0x258/0x2f0 arch/x86/entry/common.c:162
       prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
       syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
       do_syscall_64+0x6ec/0x940 arch/x86/entry/common.c:292
       entry_SYSCALL_64_after_hwframe+0x42/0xb7

-> #1 (&(&tb->tb6_lock)->rlock){+.-.}:
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
       _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168
       spin_lock_bh include/linux/spinlock.h:315 [inline]
       __ip6_ins_rt+0x56/0x90 net/ipv6/route.c:1007
       ip6_route_add+0x141/0x190 net/ipv6/route.c:2955
       addrconf_prefix_route+0x44f/0x620 net/ipv6/addrconf.c:2359
       fixup_permanent_addr net/ipv6/addrconf.c:3368 [inline]
       addrconf_permanent_addr net/ipv6/addrconf.c:3391 [inline]
       addrconf_notify+0x1ad2/0x2310 net/ipv6/addrconf.c:3460
       notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93
       __raw_notifier_call_chain kernel/notifier.c:394 [inline]
       raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
       call_netdevice_notifiers_info+0x32/0x70 net/core/dev.c:1707
       call_netdevice_notifiers net/core/dev.c:1725 [inline]
       __dev_notify_flags+0x15d/0x430 net/core/dev.c:6958
       dev_change_flags+0xf5/0x140 net/core/dev.c:6994
       do_setlink+0xa22/0x3bb0 net/core/rtnetlink.c:2357
       rtnl_newlink+0xf37/0x1a50 net/core/rtnetlink.c:2965
       rtnetlink_rcv_msg+0x57f/0xb10 net/core/rtnetlink.c:4641
       netlink_rcv_skb+0x14b/0x380 net/netlink/af_netlink.c:2444
       rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4659
       netlink_unicast_kernel net/netlink/af_netlink.c:1308 [inline]
       netlink_unicast+0x4c4/0x6b0 net/netlink/af_netlink.c:1334
       netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1897
       sock_sendmsg_nosec net/socket.c:629 [inline]
       sock_sendmsg+0xca/0x110 net/socket.c:639
       ___sys_sendmsg+0x767/0x8b0 net/socket.c:2047
       __sys_sendmsg+0xe5/0x210 net/socket.c:2081
       SYSC_sendmsg net/socket.c:2092 [inline]
       SyS_sendmsg+0x2d/0x50 net/socket.c:2088
       do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
       entry_SYSCALL_64_after_hwframe+0x42/0xb7

-> #0 (&ndev->lock){++--}:
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
       __raw_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline]
       _raw_write_lock_bh+0x31/0x40 kernel/locking/spinlock.c:312
       __ipv6_dev_mc_dec+0x45/0x350 net/ipv6/mcast.c:928
       ipv6_dev_mc_dec+0x110/0x1f0 net/ipv6/mcast.c:961
       pndisc_destructor+0x21a/0x340 net/ipv6/ndisc.c:392
       pneigh_ifdown net/core/neighbour.c:695 [inline]
       neigh_ifdown+0x149/0x250 net/core/neighbour.c:294
       rt6_disable_ip+0x537/0x700 net/ipv6/route.c:3874
       addrconf_ifdown+0x14b/0x14f0 net/ipv6/addrconf.c:3633
       addrconf_notify+0x5f8/0x2310 net/ipv6/addrconf.c:3557
       notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93
       __raw_notifier_call_chain kernel/notifier.c:394 [inline]
       raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
       call_netdevice_notifiers_info+0x32/0x70 net/core/dev.c:1707
       call_netdevice_notifiers net/core/dev.c:1725 [inline]
       __dev_notify_flags+0x262/0x430 net/core/dev.c:6960
       dev_change_flags+0xf5/0x140 net/core/dev.c:6994
       devinet_ioctl+0x126a/0x1ac0 net/ipv4/devinet.c:1080
       inet_ioctl+0x184/0x310 net/ipv4/af_inet.c:919
       packet_ioctl+0x1ff/0x310 net/packet/af_packet.c:4066
       sock_do_ioctl+0xef/0x390 net/socket.c:957
       sock_ioctl+0x36b/0x610 net/socket.c:1081
       vfs_ioctl fs/ioctl.c:46 [inline]
       do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686
       SYSC_ioctl fs/ioctl.c:701 [inline]
       SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
       do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
       entry_SYSCALL_64_after_hwframe+0x42/0xb7

other info that might help us debug this:

Chain exists of:
  &ndev->lock --> rt6_exception_lock --> &tbl->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&tbl->lock);
                               lock(rt6_exception_lock);
                               lock(&tbl->lock);
  lock(&ndev->lock);

 *** DEADLOCK ***

2 locks held by syz-executor7/4015:
 #0:  (rtnl_mutex){+.+.}, at: [<00000000a2f16daa>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
 #1:  (&tbl->lock){++-.}, at: [<00000000b5cb1d65>] neigh_ifdown+0x3d/0x250 net/core/neighbour.c:292

stack backtrace:
CPU: 0 PID: 4015 Comm: syz-executor7 Not tainted 4.16.0-rc4+ #277
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x24d lib/dump_stack.c:53
 print_circular_bug.isra.38+0x2cd/0x2dc kernel/locking/lockdep.c:1223
 check_prev_add kernel/locking/lockdep.c:1863 [inline]
 check_prevs_add kernel/locking/lockdep.c:1976 [inline]
 validate_chain kernel/locking/lockdep.c:2417 [inline]
 __lock_acquire+0x30a8/0x3e00 kernel/locking/lockdep.c:3431
 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
 __raw_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline]
 _raw_write_lock_bh+0x31/0x40 kernel/locking/spinlock.c:312
 __ipv6_dev_mc_dec+0x45/0x350 net/ipv6/mcast.c:928
 ipv6_dev_mc_dec+0x110/0x1f0 net/ipv6/mcast.c:961
 pndisc_destructor+0x21a/0x340 net/ipv6/ndisc.c:392
 pneigh_ifdown net/core/neighbour.c:695 [inline]
 neigh_ifdown+0x149/0x250 net/core/neighbour.c:294
 rt6_disable_ip+0x537/0x700 net/ipv6/route.c:3874
 addrconf_ifdown+0x14b/0x14f0 net/ipv6/addrconf.c:3633
 addrconf_notify+0x5f8/0x2310 net/ipv6/addrconf.c:3557
 notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93
 __raw_notifier_call_chain kernel/notifier.c:394 [inline]
 raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
 call_netdevice_notifiers_info+0x32/0x70 net/core/dev.c:1707
 call_netdevice_notifiers net/core/dev.c:1725 [inline]
 __dev_notify_flags+0x262/0x430 net/core/dev.c:6960
 dev_change_flags+0xf5/0x140 net/core/dev.c:6994
 devinet_ioctl+0x126a/0x1ac0 net/ipv4/devinet.c:1080
 inet_ioctl+0x184/0x310 net/ipv4/af_inet.c:919
 packet_ioctl+0x1ff/0x310 net/packet/af_packet.c:4066
 sock_do_ioctl+0xef/0x390 net/socket.c:957
 sock_ioctl+0x36b/0x610 net/socket.c:1081
 vfs_ioctl fs/ioctl.c:46 [inline]
 do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Fixes: c757faa8bfa2 ("ipv6: prepare fib6_age() for exception table")
Signed-off-by: Eric Dumazet 
Cc: Wei Wang 
Cc: Martin KaFai Lau 
Acked-by: Wei Wang 
Signed-off-by: David S. Miller

net/ipv6: Handle onlink flag with multipath routes

2018-03-22T16:40:04+00:00

For multipath routes the ONLINK flag can be specified per nexthop in
rtnh_flags or globally in rtm_flags. Update ip6_route_multipath_add
to consider the ONLINK setting coming from rtnh_flags. Each loop over
nexthops the config for the sibling route is initialized to the global
config and then per nexthop settings overlayed. The flag is 'or'ed into
fib6_config to handle the ONLINK flag coming from either rtm_flags or
rtnh_flags.

Fixes: fc1e64e1092f ("net/ipv6: Add support for onlink flag")
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

ipv6: sr: fix NULL pointer dereference when setting encap source address

2018-03-22T16:22:45+00:00

When using seg6 in encap mode, we call ipv6_dev_get_saddr() to set the
source address of the outer IPv6 header, in case none was specified.
Using skb->dev can lead to BUG() when it is in an inconsistent state.
This patch uses the net_device attached to the skb's dst instead.

[940807.667429] BUG: unable to handle kernel NULL pointer dereference at 000000000000047c
[940807.762427] IP: ipv6_dev_get_saddr+0x8b/0x1d0
[940807.815725] PGD 0 P4D 0
[940807.847173] Oops: 0000 [#1] SMP PTI
[940807.890073] Modules linked in:
[940807.927765] CPU: 6 PID: 0 Comm: swapper/6 Tainted: G        W        4.16.0-rc1-seg6bpf+ #2
[940808.028988] Hardware name: HP ProLiant DL120 G6/ProLiant DL120 G6, BIOS O26    09/06/2010
[940808.128128] RIP: 0010:ipv6_dev_get_saddr+0x8b/0x1d0
[940808.187667] RSP: 0018:ffff88043fd836b0 EFLAGS: 00010206
[940808.251366] RAX: 0000000000000005 RBX: ffff88042cb1c860 RCX: 00000000000000fe
[940808.338025] RDX: 00000000000002c0 RSI: ffff88042cb1c860 RDI: 0000000000004500
[940808.424683] RBP: ffff88043fd83740 R08: 0000000000000000 R09: ffffffffffffffff
[940808.511342] R10: 0000000000000040 R11: 0000000000000000 R12: ffff88042cb1c850
[940808.598012] R13: ffffffff8208e380 R14: ffff88042ac8da00 R15: 0000000000000002
[940808.684675] FS:  0000000000000000(0000) GS:ffff88043fd80000(0000) knlGS:0000000000000000
[940808.783036] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[940808.852975] CR2: 000000000000047c CR3: 00000004255fe000 CR4: 00000000000006e0
[940808.939634] Call Trace:
[940808.970041]  
[940808.995250]  ? ip6t_do_table+0x265/0x640
[940809.043341]  seg6_do_srh_encap+0x28f/0x300
[940809.093516]  ? seg6_do_srh+0x1a0/0x210
[940809.139528]  seg6_do_srh+0x1a0/0x210
[940809.183462]  seg6_output+0x28/0x1e0
[940809.226358]  lwtunnel_output+0x3f/0x70
[940809.272370]  ip6_xmit+0x2b8/0x530
[940809.313185]  ? ac6_proc_exit+0x20/0x20
[940809.359197]  inet6_csk_xmit+0x7d/0xc0
[940809.404173]  tcp_transmit_skb+0x548/0x9a0
[940809.453304]  __tcp_retransmit_skb+0x1a8/0x7a0
[940809.506603]  ? ip6_default_advmss+0x40/0x40
[940809.557824]  ? tcp_current_mss+0x24/0x90
[940809.605925]  tcp_retransmit_skb+0xd/0x80
[940809.654016]  tcp_xmit_retransmit_queue.part.17+0xf9/0x210
[940809.719797]  tcp_ack+0xa47/0x1110
[940809.760612]  tcp_rcv_established+0x13c/0x570
[940809.812865]  tcp_v6_do_rcv+0x151/0x3d0
[940809.858879]  tcp_v6_rcv+0xa5c/0xb10
[940809.901770]  ? seg6_output+0xdd/0x1e0
[940809.946745]  ip6_input_finish+0xbb/0x460
[940809.994837]  ip6_input+0x74/0x80
[940810.034612]  ? ip6_rcv_finish+0xb0/0xb0
[940810.081663]  ipv6_rcv+0x31c/0x4c0
...

Fixes: 6c8702c60b886 ("ipv6: sr: add support for SRH encapsulation and injection with lwtunnels")
Reported-by: Tom Herbert 
Signed-off-by: David Lebrun 
Signed-off-by: David S. Miller