Commit Graph

968 Commits

Author SHA1 Message Date
Eric Dumazet f73cbdd1b8 ipv6: make exception cache less predictible
[ Upstream commit a00df2caffed3883c341d5685f830434312e4a43 ]

Even after commit 4785305c05b2 ("ipv6: use siphash in rt6_exception_hash()"),
an attacker can still use brute force to learn some secrets from a victim
linux host.

One way to defeat these attacks is to make the max depth of the hash
table bucket a random value.

Before this patch, each bucket of the hash table used to store exceptions
could contain 6 items under attack.

After the patch, each bucket would contains a random number of items,
between 6 and 10. The attacker can no longer infer secrets.

This is slightly increasing memory size used by the hash table,
we do not expect this to be a problem.

Following patch is dealing with the same issue in IPv4.

Fixes: 35732d01fe ("ipv6: introduce a hash table to store dst cache")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Keyu Man <kman001@ucr.edu>
Cc: Wei Wang <weiwan@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15 09:47:37 +02:00
Paolo Abeni 8302513614 ipv6: fix another slab-out-of-bounds in fib6_nh_flush_exceptions
[ Upstream commit 8fb4792f091e608a0a1d353dfdf07ef55a719db5 ]

While running the self-tests on a KASAN enabled kernel, I observed a
slab-out-of-bounds splat very similar to the one reported in
commit 821bbf79fe46 ("ipv6: Fix KASAN: slab-out-of-bounds Read in
 fib6_nh_flush_exceptions").

We additionally need to take care of fib6_metrics initialization
failure when the caller provides an nh.

The fix is similar, explicitly free the route instead of calling
fib6_info_release on a half-initialized object.

Fixes: f88d8ea67f ("ipv6: Plumb support for nexthop object in a fib6_info")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-28 13:30:57 +02:00
Coco Li 7ba7fa78a9 ipv6: Fix KASAN: slab-out-of-bounds Read in fib6_nh_flush_exceptions
[ Upstream commit 821bbf79fe46a8b1d18aa456e8ed0a3c208c3754 ]

Reported by syzbot:
HEAD commit:    90c911ad Merge tag 'fixes' of git://git.kernel.org/pub/scm..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
dashboard link: https://syzkaller.appspot.com/bug?extid=123aa35098fd3c000eb7
compiler:       Debian clang version 11.0.1-2

==================================================================
BUG: KASAN: slab-out-of-bounds in fib6_nh_get_excptn_bucket net/ipv6/route.c:1604 [inline]
BUG: KASAN: slab-out-of-bounds in fib6_nh_flush_exceptions+0xbd/0x360 net/ipv6/route.c:1732
Read of size 8 at addr ffff8880145c78f8 by task syz-executor.4/17760

CPU: 0 PID: 17760 Comm: syz-executor.4 Not tainted 5.12.0-rc8-syzkaller #0
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x202/0x31e lib/dump_stack.c:120
 print_address_description+0x5f/0x3b0 mm/kasan/report.c:232
 __kasan_report mm/kasan/report.c:399 [inline]
 kasan_report+0x15c/0x200 mm/kasan/report.c:416
 fib6_nh_get_excptn_bucket net/ipv6/route.c:1604 [inline]
 fib6_nh_flush_exceptions+0xbd/0x360 net/ipv6/route.c:1732
 fib6_nh_release+0x9a/0x430 net/ipv6/route.c:3536
 fib6_info_destroy_rcu+0xcb/0x1c0 net/ipv6/ip6_fib.c:174
 rcu_do_batch kernel/rcu/tree.c:2559 [inline]
 rcu_core+0x8f6/0x1450 kernel/rcu/tree.c:2794
 __do_softirq+0x372/0x7a6 kernel/softirq.c:345
 invoke_softirq kernel/softirq.c:221 [inline]
 __irq_exit_rcu+0x22c/0x260 kernel/softirq.c:422
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:434
 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
RIP: 0010:lock_acquire+0x1f6/0x720 kernel/locking/lockdep.c:5515
Code: f6 84 24 a1 00 00 00 02 0f 85 8d 02 00 00 f7 c3 00 02 00 00 49 bd 00 00 00 00 00 fc ff df 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 4b c7 44 3d 09 00 00 00 00 43 c7 44 3d
RSP: 0018:ffffc90009e06560 EFLAGS: 00000206
RAX: 1ffff920013c0cc0 RBX: 0000000000000246 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90009e066e0 R08: dffffc0000000000 R09: fffffbfff1f992b1
R10: fffffbfff1f992b1 R11: 0000000000000000 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff920013c0cb4
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:267
 rcu_read_lock include/linux/rcupdate.h:656 [inline]
 ext4_get_group_info+0xea/0x340 fs/ext4/ext4.h:3231
 ext4_mb_prefetch+0x123/0x5d0 fs/ext4/mballoc.c:2212
 ext4_mb_regular_allocator+0x8a5/0x28f0 fs/ext4/mballoc.c:2379
 ext4_mb_new_blocks+0xc6e/0x24f0 fs/ext4/mballoc.c:4982
 ext4_ext_map_blocks+0x2be3/0x7210 fs/ext4/extents.c:4238
 ext4_map_blocks+0xab3/0x1cb0 fs/ext4/inode.c:638
 ext4_getblk+0x187/0x6c0 fs/ext4/inode.c:848
 ext4_bread+0x2a/0x1c0 fs/ext4/inode.c:900
 ext4_append+0x1a4/0x360 fs/ext4/namei.c:67
 ext4_init_new_dir+0x337/0xa10 fs/ext4/namei.c:2768
 ext4_mkdir+0x4b8/0xc00 fs/ext4/namei.c:2814
 vfs_mkdir+0x45b/0x640 fs/namei.c:3819
 ovl_do_mkdir fs/overlayfs/overlayfs.h:161 [inline]
 ovl_mkdir_real+0x53/0x1a0 fs/overlayfs/dir.c:146
 ovl_create_real+0x280/0x490 fs/overlayfs/dir.c:193
 ovl_workdir_create+0x425/0x600 fs/overlayfs/super.c:788
 ovl_make_workdir+0xed/0x1140 fs/overlayfs/super.c:1355
 ovl_get_workdir fs/overlayfs/super.c:1492 [inline]
 ovl_fill_super+0x39ee/0x5370 fs/overlayfs/super.c:2035
 mount_nodev+0x52/0xe0 fs/super.c:1413
 legacy_get_tree+0xea/0x180 fs/fs_context.c:592
 vfs_get_tree+0x86/0x270 fs/super.c:1497
 do_new_mount fs/namespace.c:2903 [inline]
 path_mount+0x196f/0x2be0 fs/namespace.c:3233
 do_mount fs/namespace.c:3246 [inline]
 __do_sys_mount fs/namespace.c:3454 [inline]
 __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3431
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665f9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f68f2b87188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 00000000004665f9
RDX: 00000000200000c0 RSI: 0000000020000000 RDI: 000000000040000a
RBP: 00000000004bfbb9 R08: 0000000020000100 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007ffe19002dff R14: 00007f68f2b87300 R15: 0000000000022000

Allocated by task 17768:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:427 [inline]
 ____kasan_kmalloc+0xc2/0xf0 mm/kasan/common.c:506
 kasan_kmalloc include/linux/kasan.h:233 [inline]
 __kmalloc+0xb4/0x380 mm/slub.c:4055
 kmalloc include/linux/slab.h:559 [inline]
 kzalloc include/linux/slab.h:684 [inline]
 fib6_info_alloc+0x2c/0xd0 net/ipv6/ip6_fib.c:154
 ip6_route_info_create+0x55d/0x1a10 net/ipv6/route.c:3638
 ip6_route_add+0x22/0x120 net/ipv6/route.c:3728
 inet6_rtm_newroute+0x2cd/0x2260 net/ipv6/route.c:5352
 rtnetlink_rcv_msg+0xb34/0xe70 net/core/rtnetlink.c:5553
 netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2502
 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
 netlink_unicast+0x7de/0x9b0 net/netlink/af_netlink.c:1338
 netlink_sendmsg+0xaa6/0xe90 net/netlink/af_netlink.c:1927
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg net/socket.c:674 [inline]
 ____sys_sendmsg+0x5a2/0x900 net/socket.c:2350
 ___sys_sendmsg net/socket.c:2404 [inline]
 __sys_sendmsg+0x319/0x400 net/socket.c:2433
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Last potentially related work creation:
 kasan_save_stack+0x27/0x50 mm/kasan/common.c:38
 kasan_record_aux_stack+0xee/0x120 mm/kasan/generic.c:345
 __call_rcu kernel/rcu/tree.c:3039 [inline]
 call_rcu+0x1b1/0xa30 kernel/rcu/tree.c:3114
 fib6_info_release include/net/ip6_fib.h:337 [inline]
 ip6_route_info_create+0x10c4/0x1a10 net/ipv6/route.c:3718
 ip6_route_add+0x22/0x120 net/ipv6/route.c:3728
 inet6_rtm_newroute+0x2cd/0x2260 net/ipv6/route.c:5352
 rtnetlink_rcv_msg+0xb34/0xe70 net/core/rtnetlink.c:5553
 netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2502
 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
 netlink_unicast+0x7de/0x9b0 net/netlink/af_netlink.c:1338
 netlink_sendmsg+0xaa6/0xe90 net/netlink/af_netlink.c:1927
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg net/socket.c:674 [inline]
 ____sys_sendmsg+0x5a2/0x900 net/socket.c:2350
 ___sys_sendmsg net/socket.c:2404 [inline]
 __sys_sendmsg+0x319/0x400 net/socket.c:2433
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Second to last potentially related work creation:
 kasan_save_stack+0x27/0x50 mm/kasan/common.c:38
 kasan_record_aux_stack+0xee/0x120 mm/kasan/generic.c:345
 insert_work+0x54/0x400 kernel/workqueue.c:1331
 __queue_work+0x981/0xcc0 kernel/workqueue.c:1497
 queue_work_on+0x111/0x200 kernel/workqueue.c:1524
 queue_work include/linux/workqueue.h:507 [inline]
 call_usermodehelper_exec+0x283/0x470 kernel/umh.c:433
 kobject_uevent_env+0x1349/0x1730 lib/kobject_uevent.c:617
 kvm_uevent_notify_change+0x309/0x3b0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4809
 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:877 [inline]
 kvm_put_kvm+0x9c/0xd10 arch/x86/kvm/../../../virt/kvm/kvm_main.c:920
 kvm_vcpu_release+0x53/0x60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3120
 __fput+0x352/0x7b0 fs/file_table.c:280
 task_work_run+0x146/0x1c0 kernel/task_work.c:140
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
 exit_to_user_mode_prepare+0x10b/0x1e0 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x26/0x70 kernel/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff8880145c7800
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 56 bytes to the right of
 192-byte region [ffff8880145c7800, ffff8880145c78c0)
The buggy address belongs to the page:
page:ffffea00005171c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x145c7
flags: 0xfff00000000200(slab)
raw: 00fff00000000200 ffffea00006474c0 0000000200000002 ffff888010c41a00
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880145c7780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8880145c7800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880145c7880: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
                                                                ^
 ffff8880145c7900: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880145c7980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================

In the ip6_route_info_create function, in the case that the nh pointer
is not NULL, the fib6_nh in fib6_info has not been allocated.
Therefore, when trying to free fib6_info in this error case using
fib6_info_release, the function will call fib6_info_destroy_rcu,
which it will access fib6_nh_release(f6i->fib6_nh);
However, f6i->fib6_nh doesn't have any refcount yet given the lack of allocation
causing the reported memory issue above.
Therefore, releasing the empty pointer directly instead would be the solution.

Fixes: f88d8ea67f ("ipv6: Plumb support for nexthop object in a fib6_info")
Fixes: 706ec91916462 ("ipv6: Fix nexthop refcnt leak when creating ipv6 route info")
Signed-off-by: Coco Li <lixiaoyan@google.com>
Cc: David Ahern <dsahern@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-10 13:37:05 +02:00
Muhammad Usama Anjum 6649b5eda1 net: ipv6: check for validity before dereferencing cfg->fc_nlinfo.nlh
commit 864db232dc7036aa2de19749c3d5be0143b24f8f upstream.

nlh is being checked for validtity two times when it is dereferenced in
this function. Check for validity again when updating the flags through
nlh pointer to make the dereferencing safe.

CC: <stable@vger.kernel.org>
Addresses-Coverity: ("NULL pointer dereference")
Signed-off-by: Muhammad Usama Anjum <musamaanjum@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-14 08:24:10 +02:00
Xiyu Yang bd68177f26 ipv6: Fix nexthop refcnt leak when creating ipv6 route info
[ Upstream commit 706ec919164622ff5ce822065472d0f30a9e9dd2 ]

ip6_route_info_create() invokes nexthop_get(), which increases the
refcount of the "nh".

When ip6_route_info_create() returns, local variable "nh" becomes
invalid, so the refcount should be decreased to keep refcount balanced.

The reference counting issue happens in one exception handling path of
ip6_route_info_create(). When nexthops can not be used with source
routing, the function forgets to decrease the refcnt increased by
nexthop_get(), causing a refcnt leak.

Fix this issue by pulling up the error source routing handling when
nexthops can not be used with source routing.

Fixes: f88d8ea67f ("ipv6: Plumb support for nexthop object in a fib6_info")
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-11 15:33:39 +02:00
David Ahern f8646548ee ipv6: Fix use of anycast address with loopback
[ Upstream commit aea23c323d89836bcdcee67e49def997ffca043b ]

Thomas reported a regression with IPv6 and anycast using the following
reproducer:

    echo 1 >  /proc/sys/net/ipv6/conf/all/forwarding
    ip -6 a add fc12::1/16 dev lo
    sleep 2
    echo "pinging lo"
    ping6 -c 2 fc12::

The conversion of addrconf_f6i_alloc to use ip6_route_info_create missed
the use of fib6_is_reject which checks addresses added to the loopback
interface and sets the REJECT flag as needed. Update fib6_is_reject for
loopback checks to handle RTF_ANYCAST addresses.

Fixes: c7a1ce397a ("ipv6: Change addrconf_f6i_alloc to use ip6_route_info_create")
Reported-by: thomas.gambier@nexedi.com
Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-22 09:32:47 +02:00
David Ahern 75270f8196 ipv6: fib6_select_path can not use out path for nexthop objects
[ Upstream commit 34fe5a1cf95c3f114068fc16d919c9cf4b00e428 ]

Brian reported a crash in IPv6 code when using rpfilter with a setup
running FRR and external nexthop objects. The root cause of the crash
is fib6_select_path setting fib6_nh in the result to NULL because of
an improper check for nexthop objects.

More specifically, rpfilter invokes ip6_route_lookup with flowi6_oif
set causing fib6_select_path to be called with have_oif_match set.
fib6_select_path has early check on have_oif_match and jumps to the
out label which presumes a builtin fib6_nh. This path is invalid for
nexthop objects; for external nexthops fib6_select_path needs to just
return if the fib6_nh has already been set in the result otherwise it
returns after the call to nexthop_path_fib6_result. Update the check
on have_oif_match to not bail on external nexthops.

Update selftests for this problem.

Fixes: f88d8ea67f ("ipv6: Plumb support for nexthop object in a fib6_info")
Reported-by: Brian Rak <brak@choopa.com>
Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-22 09:32:47 +02:00
Maciej Żenczykowski f152793058 Revert "ipv6: add mtu lock check in __ip6_rt_update_pmtu"
[ Upstream commit 09454fd0a4ce23cb3d8af65066c91a1bf27120dd ]

This reverts commit 19bda36c4299ce3d7e5bce10bebe01764a655a6d:

| ipv6: add mtu lock check in __ip6_rt_update_pmtu
|
| Prior to this patch, ipv6 didn't do mtu lock check in ip6_update_pmtu.
| It leaded to that mtu lock doesn't really work when receiving the pkt
| of ICMPV6_PKT_TOOBIG.
|
| This patch is to add mtu lock check in __ip6_rt_update_pmtu just as ipv4
| did in __ip_rt_update_pmtu.

The above reasoning is incorrect.  IPv6 *requires* icmp based pmtu to work.
There's already a comment to this effect elsewhere in the kernel:

  $ git grep -p -B1 -A3 'RTAX_MTU lock'
  net/ipv6/route.c=4813=

  static int rt6_mtu_change_route(struct fib6_info *f6i, void *p_arg)
  ...
    /* In IPv6 pmtu discovery is not optional,
       so that RTAX_MTU lock cannot disable it.
       We still use this lock to block changes
       caused by addrconf/ndisc.
    */

This reverts to the pre-4.9 behaviour.

Cc: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Xin Long <lucien.xin@gmail.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Fixes: 19bda36c42 ("ipv6: add mtu lock check in __ip6_rt_update_pmtu")
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20 08:20:09 +02:00
David Ahern 5d7e1e23ef ipv6: Use global sernum for dst validation with nexthop objects
[ Upstream commit 8f34e53b60b337e559f1ea19e2780ff95ab2fa65 ]

Nik reported a bug with pcpu dst cache when nexthop objects are
used illustrated by the following:
    $ ip netns add foo
    $ ip -netns foo li set lo up
    $ ip -netns foo addr add 2001:db8:11::1/128 dev lo
    $ ip netns exec foo sysctl net.ipv6.conf.all.forwarding=1
    $ ip li add veth1 type veth peer name veth2
    $ ip li set veth1 up
    $ ip addr add 2001:db8:10::1/64 dev veth1
    $ ip li set dev veth2 netns foo
    $ ip -netns foo li set veth2 up
    $ ip -netns foo addr add 2001:db8:10::2/64 dev veth2
    $ ip -6 nexthop add id 100 via 2001:db8:10::2 dev veth1
    $ ip -6 route add 2001:db8:11::1/128 nhid 100

    Create a pcpu entry on cpu 0:
    $ taskset -a -c 0 ip -6 route get 2001:db8:11::1

    Re-add the route entry:
    $ ip -6 ro del 2001:db8:11::1
    $ ip -6 route add 2001:db8:11::1/128 nhid 100

    Route get on cpu 0 returns the stale pcpu:
    $ taskset -a -c 0 ip -6 route get 2001:db8:11::1
    RTNETLINK answers: Network is unreachable

    While cpu 1 works:
    $ taskset -a -c 1 ip -6 route get 2001:db8:11::1
    2001:db8:11::1 from :: via 2001:db8:10::2 dev veth1 src 2001:db8:10::1 metric 1024 pref medium

Conversion of FIB entries to work with external nexthop objects
missed an important difference between IPv4 and IPv6 - how dst
entries are invalidated when the FIB changes. IPv4 has a per-network
namespace generation id (rt_genid) that is bumped on changes to the FIB.
Checking if a dst_entry is still valid means comparing rt_genid in the
rtable to the current value of rt_genid for the namespace.

IPv6 also has a per network namespace counter, fib6_sernum, but the
count is saved per fib6_node. With the per-node counter only dst_entries
based on fib entries under the node are invalidated when changes are
made to the routes - limiting the scope of invalidations. IPv6 uses a
reference in the rt6_info, 'from', to track the corresponding fib entry
used to create the dst_entry. When validating a dst_entry, the 'from'
is used to backtrack to the fib6_node and check the sernum of it to the
cookie passed to the dst_check operation.

With the inline format (nexthop definition inline with the fib6_info),
dst_entries cached in the fib6_nh have a 1:1 correlation between fib
entries, nexthop data and dst_entries. With external nexthops, IPv6
looks more like IPv4 which means multiple fib entries across disparate
fib6_nodes can all reference the same fib6_nh. That means validation
of dst_entries based on external nexthops needs to use the IPv4 format
- the per-network namespace counter.

Add sernum to rt6_info and set it when creating a pcpu dst entry. Update
rt6_get_cookie to return sernum if it is set and update dst_check for
IPv6 to look for sernum set and based the check on it if so. Finally,
rt6_get_pcpu_route needs to validate the cached entry before returning
a pcpu entry (similar to the rt_cache_valid calls in __mkroute_input and
__mkroute_output for IPv4).

This problem only affects routes using the new, external nexthops.

Thanks to the kbuild test robot for catching the IS_ENABLED needed
around rt_genid_ipv6 before I sent this out.

Fixes: 5b98324ebe ("ipv6: Allow routes to use nexthop objects")
Reported-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Tested-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-14 07:58:20 +02:00
Benjamin Poirier 8097108725 ipv6: Fix nlmsg_flags when splitting a multipath route
[ Upstream commit afecdb376bd81d7e16578f0cfe82a1aec7ae18f3 ]

When splitting an RTA_MULTIPATH request into multiple routes and adding the
second and later components, we must not simply remove NLM_F_REPLACE but
instead replace it by NLM_F_CREATE. Otherwise, it may look like the netlink
message was malformed.

For example,
	ip route add 2001:db8::1/128 dev dummy0
	ip route change 2001:db8::1/128 nexthop via fe80::30:1 dev dummy0 \
		nexthop via fe80::30:2 dev dummy0
results in the following warnings:
[ 1035.057019] IPv6: RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE
[ 1035.057517] IPv6: NLM_F_CREATE should be set when creating new route

This patch makes the nlmsg sequence look equivalent for __ip6_ins_rt() to
what it would get if the multipath route had been added in multiple netlink
operations:
	ip route add 2001:db8::1/128 dev dummy0
	ip route change 2001:db8::1/128 nexthop via fe80::30:1 dev dummy0
	ip route append 2001:db8::1/128 nexthop via fe80::30:2 dev dummy0

Fixes: 2759647247 ("ipv6: fix ECMP route replacement")
Signed-off-by: Benjamin Poirier <bpoirier@cumulusnetworks.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-05 16:43:35 +01:00
Hangbin Liu d49ce85cad net: add bool confirm_neigh parameter for dst_ops.update_pmtu
[ Upstream commit bd085ef678b2cc8c38c105673dfe8ff8f5ec0c57 ]

The MTU update code is supposed to be invoked in response to real
networking events that update the PMTU. In IPv6 PMTU update function
__ip6_rt_update_pmtu() we called dst_confirm_neigh() to update neighbor
confirmed time.

But for tunnel code, it will call pmtu before xmit, like:
  - tnl_update_pmtu()
    - skb_dst_update_pmtu()
      - ip6_rt_update_pmtu()
        - __ip6_rt_update_pmtu()
          - dst_confirm_neigh()

If the tunnel remote dst mac address changed and we still do the neigh
confirm, we will not be able to update neigh cache and ping6 remote
will failed.

So for this ip_tunnel_xmit() case, _EVEN_ if the MTU is changed, we
should not be invoking dst_confirm_neigh() as we have no evidence
of successful two-way communication at this point.

On the other hand it is also important to keep the neigh reachability fresh
for TCP flows, so we cannot remove this dst_confirm_neigh() call.

To fix the issue, we have to add a new bool parameter for dst_ops.update_pmtu
to choose whether we should do neigh update or not. I will add the parameter
in this patch and set all the callers to true to comply with the previous
way, and fix the tunnel code one by one on later patches.

v5: No change.
v4: No change.
v3: Do not remove dst_confirm_neigh, but add a new bool parameter in
    dst_ops.update_pmtu to control whether we should do neighbor confirm.
    Also split the big patch to small ones for each area.
v2: Remove dst_confirm_neigh in __ip6_rt_update_pmtu.

Suggested-by: David Miller <davem@davemloft.net>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-04 19:18:58 +01:00
Hangbin Liu 004b39427f ipv6/route: return if there is no fib_nh_gw_family
Previously we will return directly if (!rt || !rt->fib6_nh.fib_nh_gw_family)
in function rt6_probe(), but after commit cc3a86c802
("ipv6: Change rt6_probe to take a fib6_nh"), the logic changed to
return if there is fib_nh_gw_family.

Fixes: cc3a86c802 ("ipv6: Change rt6_probe to take a fib6_nh")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-20 12:17:39 -08:00
Eric Dumazet 1bef4c223b ipv6: fixes rt6_probe() and fib6_nh->last_probe init
While looking at a syzbot KCSAN report [1], I found multiple
issues in this code :

1) fib6_nh->last_probe has an initial value of 0.

   While probably okay on 64bit kernels, this causes an issue
   on 32bit kernels since the time_after(jiffies, 0 + interval)
   might be false ~24 days after boot (for HZ=1000)

2) The data-race found by KCSAN
   I could use READ_ONCE() and WRITE_ONCE(), but we also can
   take the opportunity of not piling-up too many rt6_probe_deferred()
   works by using instead cmpxchg() so that only one cpu wins the race.

[1]
BUG: KCSAN: data-race in find_match / find_match

write to 0xffff8880bb7aabe8 of 8 bytes by interrupt on cpu 1:
 rt6_probe net/ipv6/route.c:663 [inline]
 find_match net/ipv6/route.c:757 [inline]
 find_match+0x5bd/0x790 net/ipv6/route.c:733
 __find_rr_leaf+0xe3/0x780 net/ipv6/route.c:831
 find_rr_leaf net/ipv6/route.c:852 [inline]
 rt6_select net/ipv6/route.c:896 [inline]
 fib6_table_lookup+0x383/0x650 net/ipv6/route.c:2164
 ip6_pol_route+0xee/0x5c0 net/ipv6/route.c:2200
 ip6_pol_route_output+0x48/0x60 net/ipv6/route.c:2452
 fib6_rule_lookup+0x3d6/0x470 net/ipv6/fib6_rules.c:117
 ip6_route_output_flags_noref+0x16b/0x230 net/ipv6/route.c:2484
 ip6_route_output_flags+0x50/0x1a0 net/ipv6/route.c:2497
 ip6_dst_lookup_tail+0x25d/0xc30 net/ipv6/ip6_output.c:1049
 ip6_dst_lookup_flow+0x68/0x120 net/ipv6/ip6_output.c:1150
 inet6_csk_route_socket+0x2f7/0x420 net/ipv6/inet6_connection_sock.c:106
 inet6_csk_xmit+0x91/0x1f0 net/ipv6/inet6_connection_sock.c:121
 __tcp_transmit_skb+0xe81/0x1d60 net/ipv4/tcp_output.c:1169
 tcp_transmit_skb net/ipv4/tcp_output.c:1185 [inline]
 tcp_xmit_probe_skb+0x19b/0x1d0 net/ipv4/tcp_output.c:3735

read to 0xffff8880bb7aabe8 of 8 bytes by interrupt on cpu 0:
 rt6_probe net/ipv6/route.c:657 [inline]
 find_match net/ipv6/route.c:757 [inline]
 find_match+0x521/0x790 net/ipv6/route.c:733
 __find_rr_leaf+0xe3/0x780 net/ipv6/route.c:831
 find_rr_leaf net/ipv6/route.c:852 [inline]
 rt6_select net/ipv6/route.c:896 [inline]
 fib6_table_lookup+0x383/0x650 net/ipv6/route.c:2164
 ip6_pol_route+0xee/0x5c0 net/ipv6/route.c:2200
 ip6_pol_route_output+0x48/0x60 net/ipv6/route.c:2452
 fib6_rule_lookup+0x3d6/0x470 net/ipv6/fib6_rules.c:117
 ip6_route_output_flags_noref+0x16b/0x230 net/ipv6/route.c:2484
 ip6_route_output_flags+0x50/0x1a0 net/ipv6/route.c:2497
 ip6_dst_lookup_tail+0x25d/0xc30 net/ipv6/ip6_output.c:1049
 ip6_dst_lookup_flow+0x68/0x120 net/ipv6/ip6_output.c:1150
 inet6_csk_route_socket+0x2f7/0x420 net/ipv6/inet6_connection_sock.c:106
 inet6_csk_xmit+0x91/0x1f0 net/ipv6/inet6_connection_sock.c:121
 __tcp_transmit_skb+0xe81/0x1d60 net/ipv4/tcp_output.c:1169

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 18894 Comm: udevd Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: cc3a86c802 ("ipv6: Change rt6_probe to take a fib6_nh")
Fixes: f547fac624 ("ipv6: rate-limit probes for neighbourless routes")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-07 16:13:13 -08:00
David S. Miller aa2eaa8c27 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Minor overlapping changes in the btusb and ixgbe drivers.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-15 14:17:27 +02:00
Stefano Brivio cbfd68913c ipv6: Don't use dst gateway directly in ip6_confirm_neigh()
This is the equivalent of commit 2c6b55f45d ("ipv6: fix neighbour
resolution with raw socket") for ip6_confirm_neigh(): we can send a
packet with MSG_CONFIRM on a raw socket for a connected route, so the
gateway would be :: here, and we should pick the next hop using
rt6_nexthop() instead.

This was found by code review and, to the best of my knowledge, doesn't
actually fix a practical issue: the destination address from the packet
is not considered while confirming a neighbour, as ip6_confirm_neigh()
calls choose_neigh_daddr() without passing the packet, so there are no
similar issues as the one fixed by said commit.

A possible source of issues with the existing implementation might come
from the fact that, if we have a cached dst, we won't consider it,
while rt6_nexthop() takes care of that. I might just not be creative
enough to find a practical problem here: the only way to affect this
with cached routes is to have one coming from an ICMPv6 redirect, but
if the next hop is a directly connected host, there should be no
topology for which a redirect applies here, and tests with redirected
routes show no differences for MSG_CONFIRM (and MSG_PROBE) packets on
raw sockets destined to a directly connected host.

However, directly using the dst gateway here is not consistent anymore
with neighbour resolution, and, in general, as we want the next hop,
using rt6_nexthop() looks like the only sane way to fetch it.

Reported-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Acked-by: Guillaume Nault <gnault@redhat.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-11 23:52:17 +01:00
Maciej Żenczykowski 8652f17c65 ipv6: addrconf_f6i_alloc - fix non-null pointer check to !IS_ERR()
Fixes a stupid bug I recently introduced...
ip6_route_info_create() returns an ERR_PTR(err) and not a NULL on error.

Fixes: d55a2e374a ("net-ipv6: fix excessive RTF_ADDRCONF flag on ::1/128 local route (and others)'")
Cc: David Ahern <dsahern@gmail.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-07 17:46:44 +02:00
Donald Sharp 7bdf4de126 net: Properly update v4 routes with v6 nexthop
When creating a v4 route that uses a v6 nexthop from a nexthop group.
Allow the kernel to properly send the nexthop as v6 via the RTA_VIA
attribute.

Broken behavior:

$ ip nexthop add via fe80::9 dev eth0
$ ip nexthop show
id 1 via fe80::9 dev eth0 scope link
$ ip route add 4.5.6.7/32 nhid 1
$ ip route show
default via 10.0.2.2 dev eth0
4.5.6.7 nhid 1 via 254.128.0.0 dev eth0
10.0.2.0/24 dev eth0 proto kernel scope link src 10.0.2.15
$

Fixed behavior:

$ ip nexthop add via fe80::9 dev eth0
$ ip nexthop show
id 1 via fe80::9 dev eth0 scope link
$ ip route add 4.5.6.7/32 nhid 1
$ ip route show
default via 10.0.2.2 dev eth0
4.5.6.7 nhid 1 via inet6 fe80::9 dev eth0
10.0.2.0/24 dev eth0 proto kernel scope link src 10.0.2.15
$

v2, v3: Addresses code review comments from David Ahern

Fixes: dcb1ecb50e (“ipv4: Prepare for fib6_nh from a nexthop object”)
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-05 12:35:58 +02:00
David Ahern 4255ff0544 ipv6: Fix RTA_MULTIPATH with nexthop objects
A change to the core nla helpers was missed during the push of
the nexthop changes. rt6_fill_node_nexthop should be calling
nla_nest_start_noflag not nla_nest_start. Currently, iproute2
does not print multipath data because of parsing issues with
the attribute.

Fixes: f88d8ea67f ("ipv6: Plumb support for nexthop object in a fib6_info")
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-05 11:59:39 +02:00
Maciej Żenczykowski d55a2e374a net-ipv6: fix excessive RTF_ADDRCONF flag on ::1/128 local route (and others)
There is a subtle change in behaviour introduced by:
  commit c7a1ce397a
  'ipv6: Change addrconf_f6i_alloc to use ip6_route_info_create'

Before that patch /proc/net/ipv6_route includes:
00000000000000000000000000000001 80 00000000000000000000000000000000 00 00000000000000000000000000000000 00000000 00000003 00000000 80200001 lo

Afterwards /proc/net/ipv6_route includes:
00000000000000000000000000000001 80 00000000000000000000000000000000 00 00000000000000000000000000000000 00000000 00000002 00000000 80240001 lo

ie. the above commit causes the ::1/128 local (automatic) route to be flagged with RTF_ADDRCONF (0x040000).

AFAICT, this is incorrect since these routes are *not* coming from RA's.

As such, this patch restores the old behaviour.

Fixes: c7a1ce397a ("ipv6: Change addrconf_f6i_alloc to use ip6_route_info_create")
Cc: David Ahern <dsahern@gmail.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-05 00:31:50 +02:00
David S. Miller 13dfb3fa49 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Just minor overlapping changes in the conflicts here.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-06 18:44:57 -07:00
David Ahern 43a4b60d04 ipv6: have a single rcu unlock point in __ip6_rt_update_pmtu
Simplify the unlock path in __ip6_rt_update_pmtu by using a
single point where rcu_read_unlock is called.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-05 13:17:54 -07:00
David Ahern cff6a327d7 ipv6: Fix unbalanced rcu locking in rt6_update_exception_stamp_rt
The nexthop path in rt6_update_exception_stamp_rt needs to call
rcu_read_unlock if it fails to find a fib6_nh match rather than
just returning.

Fixes: e659ba31d8 ("ipv6: Handle all fib6_nh in a nexthop in exception handling")
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-05 13:16:58 -07:00
Linus Torvalds 5f4fc6d440 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Fix AF_XDP cq entry leak, from Ilya Maximets.

 2) Fix handling of PHY power-down on RTL8411B, from Heiner Kallweit.

 3) Add some new PCI IDs to iwlwifi, from Ihab Zhaika.

 4) Fix handling of neigh timers wrt. entries added by userspace, from
    Lorenzo Bianconi.

 5) Various cases of missing of_node_put(), from Nishka Dasgupta.

 6) The new NET_ACT_CT needs to depend upon NF_NAT, from Yue Haibing.

 7) Various RDS layer fixes, from Gerd Rausch.

 8) Fix some more fallout from TCQ_F_CAN_BYPASS generalization, from
    Cong Wang.

 9) Fix FIB source validation checks over loopback, also from Cong Wang.

10) Use promisc for unsupported number of filters, from Justin Chen.

11) Missing sibling route unlink on failure in ipv6, from Ido Schimmel.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (90 commits)
  tcp: fix tcp_set_congestion_control() use from bpf hook
  ag71xx: fix return value check in ag71xx_probe()
  ag71xx: fix error return code in ag71xx_probe()
  usb: qmi_wwan: add D-Link DWM-222 A2 device ID
  bnxt_en: Fix VNIC accounting when enabling aRFS on 57500 chips.
  net: dsa: sja1105: Fix missing unlock on error in sk_buff()
  gve: replace kfree with kvfree
  selftests/bpf: fix test_xdp_noinline on s390
  selftests/bpf: fix "valid read map access into a read-only array 1" on s390
  net/mlx5: Replace kfree with kvfree
  MAINTAINERS: update netsec driver
  ipv6: Unlink sibling route in case of failure
  liquidio: Replace vmalloc + memset with vzalloc
  udp: Fix typo in net/ipv4/udp.c
  net: bcmgenet: use promisc for unsupported filters
  ipv6: rt6_check should return NULL if 'from' is NULL
  tipc: initialize 'validated' field of received packets
  selftests: add a test case for rp_filter
  fib: relax source validation check for loopback packets
  mlxsw: spectrum: Do not process learned records with a dummy FID
  ...
2019-07-19 10:06:06 -07:00
Matteo Croce eec4844fae proc/sysctl: add shared variables for range check
In the sysctl code the proc_dointvec_minmax() function is often used to
validate the user supplied value between an allowed range.  This
function uses the extra1 and extra2 members from struct ctl_table as
minimum and maximum allowed value.

On sysctl handler declaration, in every source file there are some
readonly variables containing just an integer which address is assigned
to the extra1 and extra2 members, so the sysctl range is enforced.

The special values 0, 1 and INT_MAX are very often used as range
boundary, leading duplication of variables like zero=0, one=1,
int_max=INT_MAX in different source files:

    $ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l
    248

Add a const int array containing the most commonly used values, some
macros to refer more easily to the correct array member, and use them
instead of creating a local one for every object file.

This is the bloat-o-meter output comparing the old and new binary
compiled with the default Fedora config:

    # scripts/bloat-o-meter -d vmlinux.o.old vmlinux.o
    add/remove: 2/2 grow/shrink: 0/2 up/down: 24/-188 (-164)
    Data                                         old     new   delta
    sysctl_vals                                    -      12     +12
    __kstrtab_sysctl_vals                          -      12     +12
    max                                           14      10      -4
    int_max                                       16       -     -16
    one                                           68       -     -68
    zero                                         128      28    -100
    Total: Before=20583249, After=20583085, chg -0.00%

[mcroce@redhat.com: tipc: remove two unused variables]
  Link: http://lkml.kernel.org/r/20190530091952.4108-1-mcroce@redhat.com
[akpm@linux-foundation.org: fix net/ipv6/sysctl_net_ipv6.c]
[arnd@arndb.de: proc/sysctl: make firmware loader table conditional]
  Link: http://lkml.kernel.org/r/20190617130014.1713870-1-arnd@arndb.de
[akpm@linux-foundation.org: fix fs/eventpoll.c]
Link: http://lkml.kernel.org/r/20190430180111.10688-1-mcroce@redhat.com
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-18 17:08:07 -07:00
David Ahern 49d05fe2c9 ipv6: rt6_check should return NULL if 'from' is NULL
Paul reported that l2tp sessions were broken after the commit referenced
in the Fixes tag. Prior to this commit rt6_check returned NULL if the
rt6_info 'from' was NULL - ie., the dst_entry was disconnected from a FIB
entry. Restore that behavior.

Fixes: 93531c6743 ("net/ipv6: separate handling of FIB entries from dst based routes")
Reported-by: Paul Donohue <linux-kernel@PaulSD.com>
Tested-by: Paul Donohue <linux-kernel@PaulSD.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-17 15:25:54 -07:00
Stephen Suryaputra d8f74f0975 ipv6: Support multipath hashing on inner IP pkts
Make the same support as commit 363887a2cd ("ipv4: Support multipath
hashing on inner IP pkts for GRE tunnel") for outer IPv6. The hashing
considers both IPv4 and IPv6 pkts when they are tunneled by IPv6 GRE.

Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-08 16:37:29 -07:00
Mahesh Bandewar 8d7017fd62 blackhole_netdev: use blackhole_netdev to invalidate dst entries
Use blackhole_netdev instead of 'lo' device with lower MTU when marking
dst "dead".

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Tested-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-01 19:34:46 -07:00
David S. Miller d96ff269a0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
The new route handling in ip_mc_finish_output() from 'net' overlapped
with the new support for returning congestion notifications from BPF
programs.

In order to handle this I had to take the dev_loopback_xmit() calls
out of the switch statement.

The aquantia driver conflicts were simple overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-27 21:06:39 -07:00
David Ahern b2c709cce6 ipv6: Convert gateway validation to use fib6_info
Gateway validation does not need a dst_entry, it only needs the fib
entry to validate the gateway resolution and egress device. So,
convert ip6_nh_lookup_table from ip6_pol_route to fib6_table_lookup
and ip6_route_check_nh to use fib6_lookup over rt6_lookup.

ip6_pol_route is a call to fib6_table_lookup and if successful a call
to fib6_select_path. From there the exception cache is searched for an
entry or a dst_entry is created to return to the caller. The exception
entry is not relevant for gateway validation, so what matters are the
calls to fib6_table_lookup and then fib6_select_path.

Similarly, rt6_lookup can be replaced with a call to fib6_lookup with
RT6_LOOKUP_F_IFACE set in flags. Again, the exception cache search is
not relevant, only the lookup with path selection. The primary difference
in the lookup paths is the use of rt6_select with fib6_lookup versus
rt6_device_match with rt6_lookup. When you remove complexities in the
rt6_select path, e.g.,
1. saddr is not set for gateway validation, so RT6_LOOKUP_F_HAS_SADDR
   is not relevant
2. rt6_check_neigh is not called so that removes the RT6_NUD_FAIL_DO_RR
   return and round-robin logic.

the code paths are believed to be equivalent for the given use case -
validate the gateway and optionally given the device. Furthermore, it
aligns the validation with onlink code path and the lookup path actually
used for rx and tx.

Adjust the users, ip6_route_check_nh_onlink and ip6_route_check_nh to
handle a fib6_info vs a rt6_info when performing validation checks.

Existing selftests fib-onlink-tests.sh and fib_tests.sh are used to
verify the changes.

Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-27 11:10:23 -07:00
Nicolas Dichtel 2c6b55f45d ipv6: fix neighbour resolution with raw socket
The scenario is the following: the user uses a raw socket to send an ipv6
packet, destinated to a not-connected network, and specify a connected nh.
Here is the corresponding python script to reproduce this scenario:

 import socket
 IPPROTO_RAW = 255
 send_s = socket.socket(socket.AF_INET6, socket.SOCK_RAW, IPPROTO_RAW)
 # scapy
 # p = IPv6(src='fd00💯:1', dst='fd00:200::fa')/ICMPv6EchoRequest()
 # str(p)
 req = b'`\x00\x00\x00\x00\x08:@\xfd\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\xfd\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xfa\x80\x00\x81\xc0\x00\x00\x00\x00'
 send_s.sendto(req, ('fd00:175::2', 0, 0, 0))

fd00:175::/64 is a connected route and fd00:200::fa is not a connected
host.

With this scenario, the kernel starts by sending a NS to resolve
fd00:175::2. When it receives the NA, it flushes its queue and try to send
the initial packet. But instead of sending it, it sends another NS to
resolve fd00:200::fa, which obvioulsy fails, thus the packet is dropped. If
the user sends again the packet, it now uses the right nh (fd00:175::2).

The problem is that ip6_dst_lookup_neigh() uses the rt6i_gateway, which is
:: because the associated route is a connected route, thus it uses the dst
addr of the packet. Let's use rt6_nexthop() to choose the right nh.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-26 13:26:08 -07:00
Eric Dumazet 3b52569152 ipv6: fix suspicious RCU usage in rt6_dump_route()
syzbot reminded us that rt6_nh_dump_exceptions() needs to be called
with rcu_read_lock()

net/ipv6/route.c:1593 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
2 locks held by syz-executor609/8966:
 #0: 00000000b7dbe288 (rtnl_mutex){+.+.}, at: netlink_dump+0xe7/0xfb0 net/netlink/af_netlink.c:2199
 #1: 00000000f2d87c21 (&(&tb->tb6_lock)->rlock){+...}, at: spin_lock_bh include/linux/spinlock.h:343 [inline]
 #1: 00000000f2d87c21 (&(&tb->tb6_lock)->rlock){+...}, at: fib6_dump_table.isra.0+0x37e/0x570 net/ipv6/ip6_fib.c:533

stack backtrace:
CPU: 0 PID: 8966 Comm: syz-executor609 Not tainted 5.2.0-rc5+ #43
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:5250
 fib6_nh_get_excptn_bucket+0x18e/0x1b0 net/ipv6/route.c:1593
 rt6_nh_dump_exceptions+0x45/0x4d0 net/ipv6/route.c:5541
 rt6_dump_route+0x904/0xc50 net/ipv6/route.c:5640
 fib6_dump_node+0x168/0x280 net/ipv6/ip6_fib.c:467
 fib6_walk_continue+0x4a9/0x8e0 net/ipv6/ip6_fib.c:1986
 fib6_walk+0x9d/0x100 net/ipv6/ip6_fib.c:2034
 fib6_dump_table.isra.0+0x38a/0x570 net/ipv6/ip6_fib.c:534
 inet6_dump_fib+0x93c/0xb00 net/ipv6/ip6_fib.c:624
 rtnl_dump_all+0x295/0x490 net/core/rtnetlink.c:3445
 netlink_dump+0x558/0xfb0 net/netlink/af_netlink.c:2244
 __netlink_dump_start+0x5b1/0x7d0 net/netlink/af_netlink.c:2352
 netlink_dump_start include/linux/netlink.h:226 [inline]
 rtnetlink_rcv_msg+0x73d/0xb00 net/core/rtnetlink.c:5182
 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5237
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0x531/0x710 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:665
 sock_write_iter+0x27c/0x3e0 net/socket.c:994
 call_write_iter include/linux/fs.h:1872 [inline]
 new_sync_write+0x4d3/0x770 fs/read_write.c:483
 __vfs_write+0xe1/0x110 fs/read_write.c:496
 vfs_write+0x20c/0x580 fs/read_write.c:558
 ksys_write+0x14f/0x290 fs/read_write.c:611
 __do_sys_write fs/read_write.c:623 [inline]
 __se_sys_write fs/read_write.c:620 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:620
 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4401b9
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffc8e134978 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004401b9
RDX: 000000000000001c RSI: 0000000020000000 RDI: 00

Fixes: 1e47b4837f ("ipv6: Dump route exceptions if requested")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stefano Brivio <sbrivio@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-26 09:07:50 -07:00
Eiichi Tsukata b8e8a86337 net/ipv6: Fix misuse of proc_dointvec "skip_notify_on_dev_down"
/proc/sys/net/ipv6/route/skip_notify_on_dev_down assumes given value to be
0 or 1. Use proc_dointvec_minmax instead of proc_dointvec.

Fixes: 7c6bb7d2fa ("net/ipv6: Add knob to skip DELROUTE message ondevice down")
Signed-off-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-25 12:59:04 -07:00
Stefano Brivio 1e47b4837f ipv6: Dump route exceptions if requested
Since commit 2b760fcf5c ("ipv6: hook up exception table to store dst
cache"), route exceptions reside in a separate hash table, and won't be
found by walking the FIB, so they won't be dumped to userspace on a
RTM_GETROUTE message.

This causes 'ip -6 route list cache' and 'ip -6 route flush cache' to
have no function anymore:

 # ip -6 route get fc00:3::1
 fc00:3::1 via fc00:1::2 dev veth_A-R1 src fc00:1::1 metric 1024 expires 539sec mtu 1400 pref medium
 # ip -6 route get fc00:4::1
 fc00:4::1 via fc00:2::2 dev veth_A-R2 src fc00:2::1 metric 1024 expires 536sec mtu 1500 pref medium
 # ip -6 route list cache
 # ip -6 route flush cache
 # ip -6 route get fc00:3::1
 fc00:3::1 via fc00:1::2 dev veth_A-R1 src fc00:1::1 metric 1024 expires 520sec mtu 1400 pref medium
 # ip -6 route get fc00:4::1
 fc00:4::1 via fc00:2::2 dev veth_A-R2 src fc00:2::1 metric 1024 expires 519sec mtu 1500 pref medium

because iproute2 lists cached routes using RTM_GETROUTE, and flushes them
by listing all the routes, and deleting them with RTM_DELROUTE one by one.

If cached routes are requested using the RTM_F_CLONED flag together with
strict checking, or if no strict checking is requested (and hence we can't
consistently apply filters), look up exceptions in the hash table
associated with the current fib6_info in rt6_dump_route(), and, if present
and not expired, add them to the dump.

We might be unable to dump all the entries for a given node in a single
message, so keep track of how many entries were handled for the current
node in fib6_walker, and skip that amount in case we start from the same
partially dumped node.

When a partial dump restarts, as the starting node might change when
'sernum' changes, we have no guarantee that we need to skip the same
amount of in-node entries. Therefore, we need two counters, and we need to
zero the in-node counter if the node from which the dump is resumed
differs.

Note that, with the current version of iproute2, this only fixes the
'ip -6 route list cache': on a flush command, iproute2 doesn't pass
RTM_F_CLONED and, due to this inconsistency, 'ip -6 route flush cache' is
still unable to fetch the routes to be flushed. This will be addressed in
a patch for iproute2.

To flush cached routes, a procfs entry could be introduced instead: that's
how it works for IPv4. We already have a rt6_flush_exception() function
ready to be wired to it. However, this would not solve the issue for
listing.

Versions of iproute2 and kernel tested:

                    iproute2
kernel             4.14.0   4.15.0   4.19.0   5.0.0   5.1.0    5.1.0, patched
 3.18    list        +        +        +        +       +            +
         flush       +        +        +        +       +            +
 4.4     list        +        +        +        +       +            +
         flush       +        +        +        +       +            +
 4.9     list        +        +        +        +       +            +
         flush       +        +        +        +       +            +
 4.14    list        +        +        +        +       +            +
         flush       +        +        +        +       +            +
 4.15    list
         flush
 4.19    list
         flush
 5.0     list
         flush
 5.1     list
         flush
 with    list        +        +        +        +       +            +
 fix     flush       +        +        +                             +

v7:
  - Explain usage of "skip" counters in commit message (suggested by
    David Ahern)

v6:
  - Rebase onto net-next, use recently introduced nexthop walker
  - Make rt6_nh_dump_exceptions() a separate function (suggested by David
    Ahern)

v5:
  - Use dump_routes and dump_exceptions from filter, ignore NLM_F_MATCH,
    update test results (flushing works with iproute2 < 5.0.0 now)

v4:
  - Split NLM_F_MATCH and strict check handling in separate patches
  - Filter routes using RTM_F_CLONED: if it's not set, only return
    non-cached routes, and if it's set, only return cached routes:
    change requested by David Ahern and Martin Lau. This implies that
    iproute2 needs a separate patch to be able to flush IPv6 cached
    routes. This is not ideal because we can't fix the breakage caused
    by 2b760fcf5c entirely in kernel. However, two years have passed
    since then, and this makes it more tolerable

v3:
  - More descriptive comment about expired exceptions in rt6_dump_route()
  - Swap return values of rt6_dump_route() (suggested by Martin Lau)
  - Don't zero skip_in_node in case we don't dump anything in a given pass
    (also suggested by Martin Lau)
  - Remove check on RTM_F_CLONED altogether: in the current UAPI semantic,
    it's just a flag to indicate the route was cloned, not to filter on
    routes

v2: Add tracking of number of entries to be skipped in current node after
    a partial dump. As we restart from the same node, if not all the
    exceptions for a given node fit in a single message, the dump will
    not terminate, as suggested by Martin Lau. This is a concrete
    possibility, setting up a big number of exceptions for the same route
    actually causes the issue, suggested by David Ahern.

Reported-by: Jianlin Shi <jishi@redhat.com>
Fixes: 2b760fcf5c ("ipv6: hook up exception table to store dst cache")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-24 10:18:49 -07:00
Stefano Brivio bf9a8a061d ipv6/route: Change return code of rt6_dump_route() for partial node dumps
In the next patch, we are going to add optional dump of exceptions to
rt6_dump_route().

Change the return code of rt6_dump_route() to accomodate partial node
dumps: we might dump multiple routes per node, and might be able to dump
only a given number of them, so fib6_dump_node() will need to know how
many routes have been dumped on partial dump, to restart the dump from the
point where it was interrupted.

Note that fib6_dump_node() is the only caller and already handles all
non-negative return codes as success: those become -1 to signal that we're
done with the node. If we fail, return 0, as we were unable to dump the
single route in the node, but we're not done with it.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-24 10:18:49 -07:00
Stefano Brivio 3401bfb163 ipv6/route: Don't match on fc_nh_id if not set in ip6_route_del()
If fc_nh_id isn't set, we shouldn't try to match against it. This
actually matters just for the RTF_CACHE below (where this case is
already handled): if iproute2 gets a route exception and tries to
delete it, it won't reference it by fc_nh_id, even if a nexthop
object might be associated to the originating route.

Fixes: 5b98324ebe ("ipv6: Allow routes to use nexthop objects")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-24 10:18:49 -07:00
Wei Wang 7d9e5f4221 ipv6: convert major tx path to use RT6_LOOKUP_F_DST_NOREF
For tx path, in most cases, we still have to take refcnt on the dst
cause the caller is caching the dst somewhere. But it still is
beneficial to make use of RT6_LOOKUP_F_DST_NOREF flag while doing the
route lookup. It is cause this flag prevents manipulating refcnt on
net->ipv6.ip6_null_entry when doing fib6_rule_lookup() to traverse each
routing table. The null_entry is a shared object and constant updates on
it cause false sharing.

We converted the current major lookup function ip6_route_output_flags()
to make use of RT6_LOOKUP_F_DST_NOREF.

Together with the change in the rx path, we see noticable performance
boost:
I ran synflood tests between 2 hosts under the same switch. Both hosts
have 20G mlx NIC, and 8 tx/rx queues.
Sender sends pure SYN flood with random src IPs and ports using trafgen.
Receiver has a simple TCP listener on the target port.
Both hosts have multiple custom rules:
- For incoming packets, only local table is traversed.
- For outgoing packets, 3 tables are traversed to find the route.
The packet processing rate on the receiver is as follows:
- Before the fix: 3.78Mpps
- After the fix:  5.50Mpps

Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-23 13:24:17 -07:00
Wei Wang 67f415dd29 ipv6: convert rx data path to not take refcnt on dst
ip6_route_input() is the key function to do the route lookup in the
rx data path. All the callers to this function are already holding rcu
lock. So it is fairly easy to convert it to not take refcnt on the dst:
We pass in flag RT6_LOOKUP_F_DST_NOREF and do skb_dst_set_noref().
This saves a few atomic inc or dec operations and should boost
performance overall.
This also makes the logic more aligned with v4.

Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-23 13:24:17 -07:00
Wei Wang 74109218b0 ipv6: initialize rt6->rt6i_uncached in all pre-allocated dst entries
Initialize rt6->rt6i_uncached on the following pre-allocated dsts:
net->ipv6.ip6_null_entry
net->ipv6.ip6_prohibit_entry
net->ipv6.ip6_blk_hole_entry

This is a preparation patch for later commits to be able to distinguish
dst entries in uncached list by doing:
!list_empty(rt6->rt6i_uncached)

Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-23 13:24:17 -07:00
Wei Wang 0e09edcce7 ipv6: introduce RT6_LOOKUP_F_DST_NOREF flag in ip6_pol_route()
This new flag is to instruct the route lookup function to not take
refcnt on the dst entry. The user which does route lookup with this flag
must properly use rcu protection.
ip6_pol_route() is the major route lookup function for both tx and rx
path.
In this function:
Do not take refcnt on dst if RT6_LOOKUP_F_DST_NOREF flag is set, and
directly return the route entry. The caller should be holding rcu lock
when using this flag, and decide whether to take refcnt or not.

One note on the dst cache in the uncached_list:
As uncached_list does not consume refcnt, one refcnt is always returned
back to the caller even if RT6_LOOKUP_F_DST_NOREF flag is set.
Uncached dst is only possible in the output path. So in such call path,
caller MUST check if the dst is in the uncached_list before assuming
that there is no refcnt taken on the returned dst.

Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-23 13:24:17 -07:00
Ido Schimmel 9eee3b4913 ipv6: Error when route does not have any valid nexthops
When user space sends invalid information in RTA_MULTIPATH, the nexthop
list in ip6_route_multipath_add() is empty and 'rt_notif' is set to
NULL.

The code that emits the in-kernel notifications does not check for this
condition, which results in a NULL pointer dereference [1].

Fix this by bailing earlier in the function if the parsed nexthop list
is empty. This is consistent with the corresponding IPv4 code.

v2:
* Check if parsed nexthop list is empty and bail with extack set

[1]
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 9190 Comm: syz-executor149 Not tainted 5.2.0-rc5+ #38
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:call_fib6_multipath_entry_notifiers+0xd1/0x1a0
net/ipv6/ip6_fib.c:396
Code: 8b b5 30 ff ff ff 48 c7 85 68 ff ff ff 00 00 00 00 48 c7 85 70 ff ff
ff 00 00 00 00 89 45 88 4c 89 e0 48 c1 e8 03 4c 89 65 80 <42> 80 3c 28 00
0f 85 9a 00 00 00 48 b8 00 00 00 00 00 fc ff df 4d
RSP: 0018:ffff88809788f2c0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffff11012f11e59 RCX: 00000000ffffffff
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88809788f390 R08: ffff88809788f8c0 R09: 000000000000000c
R10: ffff88809788f5d8 R11: ffff88809788f527 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88809788f8c0 R15: ffffffff89541d80
FS:  000055555632c880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000080 CR3: 000000009ba7c000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  ip6_route_multipath_add+0xc55/0x1490 net/ipv6/route.c:5094
  inet6_rtm_newroute+0xed/0x180 net/ipv6/route.c:5208
  rtnetlink_rcv_msg+0x463/0xb00 net/core/rtnetlink.c:5219
  netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
  rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5237
  netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
  netlink_unicast+0x531/0x710 net/netlink/af_netlink.c:1328
  netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1917
  sock_sendmsg_nosec net/socket.c:646 [inline]
  sock_sendmsg+0xd7/0x130 net/socket.c:665
  ___sys_sendmsg+0x803/0x920 net/socket.c:2286
  __sys_sendmsg+0x105/0x1d0 net/socket.c:2324
  __do_sys_sendmsg net/socket.c:2333 [inline]
  __se_sys_sendmsg net/socket.c:2331 [inline]
  __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2331
  do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4401f9
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff
ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffc09fd0028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004401f9
RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401a80
R13: 0000000000401b10 R14: 0000000000000000 R15: 0000000000000000

Reported-by: syzbot+382566d339d52cd1a204@syzkaller.appspotmail.com
Fixes: ebee3cad83 ("ipv6: Add IPv6 multipath notifications for add / replace")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-22 16:50:35 -07:00
David S. Miller 92ad6325cb Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Minor SPDX change conflict.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-22 08:59:24 -04:00
David Ahern c7036d97ac ipv6: Default fib6_type to RTN_UNICAST when not set
A user reported that routes are getting installed with type 0 (RTN_UNSPEC)
where before the routes were RTN_UNICAST. One example is from accel-ppp
which apparently still uses the ioctl interface and does not set
rtmsg_type. Another is the netlink interface where ipv6 does not require
rtm_type to be set (v4 does). Prior to the commit in the Fixes tag the
ipv6 stack converted type 0 to RTN_UNICAST, so restore that behavior.

Fixes: e8478e80e5 ("net/ipv6: Save route type in rt6_info")
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-19 17:14:05 -04:00
Ido Schimmel 2881fd61b6 ipv6: Add IPv6 multipath notification for route delete
If all the nexthops of a multipath route are being deleted, send one
notification for the entire route, instead of one per-nexthop.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-18 09:45:36 -07:00
Ido Schimmel ebee3cad83 ipv6: Add IPv6 multipath notifications for add / replace
Emit a notification when a multipath routes is added or replace.

Note that unlike the replace notifications sent from fib6_add_rt2node(),
it is possible we are sending a 'FIB_EVENT_ENTRY_REPLACE' when a route
was merely added and not replaced.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-18 09:45:36 -07:00
David Ahern 5b98324ebe ipv6: Allow routes to use nexthop objects
Add support for RTA_NH_ID attribute to allow a user to specify a
nexthop id to use with a route. fc_nh_id is added to fib6_config to
hold the value passed in the RTA_NH_ID attribute. If a nexthop id
is given, the gateway, device, encap and multipath attributes can
not be set.

Update ip6_route_del to check metric and protocol before nexthop
specs. If fc_nh_id is set, then it must match the id in the route
entry. Since IPv6 allows delete of a cached entry (an exception),
add ip6_del_cached_rt_nh to cycle through all of the fib6_nh in
a fib entry if it is using a nexthop.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-10 10:44:57 -07:00
David Ahern 2d44234bf9 ipv6: Handle all fib6_nh in a nexthop in mtu updates
Use nexthop_for_each_fib6_nh to call fib6_nh_mtu_change for each
fib6_nh in a nexthop for rt6_mtu_change_route. For __ip6_rt_update_pmtu,
we need to find the nexthop that correlates to the device and gateway
in the rt6_info.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-10 10:44:56 -07:00
David Ahern 49d5b8ef20 ipv6: Handle all fib6_nh in a nexthop in rt6_do_redirect
Use nexthop_for_each_fib6_nh and fib6_nh_find_match to find the
fib6_nh in a nexthop that correlates to the device and gateway
in the rt6_info.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-10 10:44:56 -07:00
David Ahern c55c89884d ipv6: Handle all fib6_nh in a nexthop in __ip6_route_redirect
Add a hook in __ip6_route_redirect to handle a nexthop struct in a
fib6_info. Use nexthop_for_each_fib6_nh and fib6_nh_redirect_match
to call ip6_redirect_nh_match for each fib6_nh looking for a match.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-10 10:44:56 -07:00
David Ahern e659ba31d8 ipv6: Handle all fib6_nh in a nexthop in exception handling
Add a hook in rt6_flush_exceptions, rt6_remove_exception_rt,
rt6_update_exception_stamp_rt, and rt6_age_exceptions to handle
nexthop struct in a fib6_info.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-10 10:44:56 -07:00
David Ahern 2c170e0753 ipv6: Handle all fib6_nh in a nexthop in fib6_info_uses_dev
Add a hook in fib6_info_uses_dev to handle nexthop struct in a fib6_info.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-10 10:44:56 -07:00