Commit Graph

1028 Commits

Author SHA1 Message Date
Eric Dumazet
c693698787 ipv6: fix possible race in __fib6_drop_pcpu_from()
[ Upstream commit b01e1c030770ff3b4fe37fc7cc6bca03f594133f ]

syzbot found a race in __fib6_drop_pcpu_from() [1]

If compiler reads more than once (*ppcpu_rt),
second read could read NULL, if another cpu clears
the value in rt6_get_pcpu_route().

Add a READ_ONCE() to prevent this race.

Also add rcu_read_lock()/rcu_read_unlock() because
we rely on RCU protection while dereferencing pcpu_rt.

[1]

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000012: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000090-0x0000000000000097]
CPU: 0 PID: 7543 Comm: kworker/u8:17 Not tainted 6.10.0-rc1-syzkaller-00013-g2bfcfd584ff5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: netns cleanup_net
 RIP: 0010:__fib6_drop_pcpu_from.part.0+0x10a/0x370 net/ipv6/ip6_fib.c:984
Code: f8 48 c1 e8 03 80 3c 28 00 0f 85 16 02 00 00 4d 8b 3f 4d 85 ff 74 31 e8 74 a7 fa f7 49 8d bf 90 00 00 00 48 89 f8 48 c1 e8 03 <80> 3c 28 00 0f 85 1e 02 00 00 49 8b 87 90 00 00 00 48 8b 0c 24 48
RSP: 0018:ffffc900040df070 EFLAGS: 00010206
RAX: 0000000000000012 RBX: 0000000000000001 RCX: ffffffff89932e16
RDX: ffff888049dd1e00 RSI: ffffffff89932d7c RDI: 0000000000000091
RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000007
R10: 0000000000000001 R11: 0000000000000006 R12: ffff88807fa080b8
R13: fffffbfff1a9a07d R14: ffffed100ff41022 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32c26000 CR3: 000000005d56e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
  __fib6_drop_pcpu_from net/ipv6/ip6_fib.c:966 [inline]
  fib6_drop_pcpu_from net/ipv6/ip6_fib.c:1027 [inline]
  fib6_purge_rt+0x7f2/0x9f0 net/ipv6/ip6_fib.c:1038
  fib6_del_route net/ipv6/ip6_fib.c:1998 [inline]
  fib6_del+0xa70/0x17b0 net/ipv6/ip6_fib.c:2043
  fib6_clean_node+0x426/0x5b0 net/ipv6/ip6_fib.c:2205
  fib6_walk_continue+0x44f/0x8d0 net/ipv6/ip6_fib.c:2127
  fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2175
  fib6_clean_tree+0xd7/0x120 net/ipv6/ip6_fib.c:2255
  __fib6_clean_all+0x100/0x2d0 net/ipv6/ip6_fib.c:2271
  rt6_sync_down_dev net/ipv6/route.c:4906 [inline]
  rt6_disable_ip+0x7ed/0xa00 net/ipv6/route.c:4911
  addrconf_ifdown.isra.0+0x117/0x1b40 net/ipv6/addrconf.c:3855
  addrconf_notify+0x223/0x19e0 net/ipv6/addrconf.c:3778
  notifier_call_chain+0xb9/0x410 kernel/notifier.c:93
  call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1992
  call_netdevice_notifiers_extack net/core/dev.c:2030 [inline]
  call_netdevice_notifiers net/core/dev.c:2044 [inline]
  dev_close_many+0x333/0x6a0 net/core/dev.c:1585
  unregister_netdevice_many_notify+0x46d/0x19f0 net/core/dev.c:11193
  unregister_netdevice_many net/core/dev.c:11276 [inline]
  default_device_exit_batch+0x85b/0xae0 net/core/dev.c:11759
  ops_exit_list+0x128/0x180 net/core/net_namespace.c:178
  cleanup_net+0x5b7/0xbf0 net/core/net_namespace.c:640
  process_one_work+0x9fb/0x1b60 kernel/workqueue.c:3231
  process_scheduled_works kernel/workqueue.c:3312 [inline]
  worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393
  kthread+0x2c1/0x3a0 kernel/kthread.c:389
  ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Fixes: d52d3997f8 ("ipv6: Create percpu rt6_info")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20240604193549.981839-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05 09:12:23 +02:00
Eric Dumazet
2295a7ef5c net: fix __dst_negative_advice() race
commit 92f1655aa2b2294d0b49925f3b875a634bd3b59e upstream.

__dst_negative_advice() does not enforce proper RCU rules when
sk->dst_cache must be cleared, leading to possible UAF.

RCU rules are that we must first clear sk->sk_dst_cache,
then call dst_release(old_dst).

Note that sk_dst_reset(sk) is implementing this protocol correctly,
while __dst_negative_advice() uses the wrong order.

Given that ip6_negative_advice() has special logic
against RTF_CACHE, this means each of the three ->negative_advice()
existing methods must perform the sk_dst_reset() themselves.

Note the check against NULL dst is centralized in
__dst_negative_advice(), there is no need to duplicate
it in various callbacks.

Many thanks to Clement Lecigne for tracking this issue.

This old bug became visible after the blamed commit, using UDP sockets.

Fixes: a87cb3e48e ("net: Facility to report route quality of connected sockets")
Reported-by: Clement Lecigne <clecigne@google.com>
Diagnosed-by: Clement Lecigne <clecigne@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <tom@herbertland.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240528114353.1794151-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[Lee: Stable backport]
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-16 13:32:36 +02:00
xu xin
3cc7687f7f net/ipv6: Fix route deleting failure when metric equals 0
commit bb487272380d120295e955ad8acfcbb281b57642 upstream.

Problem
=========
After commit 67f6951347 ("ipv6: Move setting default metric for routes"),
we noticed that the logic of assigning the default value of fc_metirc
changed in the ioctl process. That is, when users use ioctl(fd, SIOCADDRT,
rt) with a non-zero metric to add a route,  then they may fail to delete a
route with passing in a metric value of 0 to the kernel by ioctl(fd,
SIOCDELRT, rt). But iproute can succeed in deleting it.

As a reference, when using iproute tools by netlink to delete routes with
a metric parameter equals 0, like the command as follows:

	ip -6 route del fe80::/64 via fe81::5054:ff:fe11:3451 dev eth0 metric 0

the user can still succeed in deleting the route entry with the smallest
metric.

Root Reason
===========
After commit 67f6951347 ("ipv6: Move setting default metric for routes"),
When ioctl() pass in SIOCDELRT with a zero metric, rtmsg_to_fib6_config()
will set a defalut value (1024) to cfg->fc_metric in kernel, and in
ip6_route_del() and the line 4074 at net/ipv3/route.c, it will check by

	if (cfg->fc_metric && cfg->fc_metric != rt->fib6_metric)
		continue;

and the condition is true and skip the later procedure (deleting route)
because cfg->fc_metric != rt->fib6_metric. But before that commit,
cfg->fc_metric is still zero there, so the condition is false and it
will do the following procedure (deleting).

Solution
========
In order to keep a consistent behaviour across netlink() and ioctl(), we
should allow to delete a route with a metric value of 0. So we only do
the default setting of fc_metric in route adding.

CC: stable@vger.kernel.org # 5.4+
Fixes: 67f6951347 ("ipv6: Move setting default metric for routes")
Co-developed-by: Fan Yu <fan.yu9@zte.com.cn>
Signed-off-by: Fan Yu <fan.yu9@zte.com.cn>
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240514201102055dD2Ba45qKbLlUMxu_DTHP@zte.com.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-16 13:32:34 +02:00
Eric Dumazet
79ce2e54cc net/ipv6: avoid possible UAF in ip6_route_mpath_notify()
[ Upstream commit 685f7d531264599b3f167f1e94bbd22f120e5fab ]

syzbot found another use-after-free in ip6_route_mpath_notify() [1]

Commit f7225172f2 ("net/ipv6: prevent use after free in
ip6_route_mpath_notify") was not able to fix the root cause.

We need to defer the fib6_info_release() calls after
ip6_route_mpath_notify(), in the cleanup phase.

[1]
BUG: KASAN: slab-use-after-free in rt6_fill_node+0x1460/0x1ac0
Read of size 4 at addr ffff88809a07fc64 by task syz-executor.2/23037

CPU: 0 PID: 23037 Comm: syz-executor.2 Not tainted 6.8.0-rc4-syzkaller-01035-gea7f3cfaa588 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
 <TASK>
  __dump_stack lib/dump_stack.c:88 [inline]
  dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106
  print_address_description mm/kasan/report.c:377 [inline]
  print_report+0x167/0x540 mm/kasan/report.c:488
  kasan_report+0x142/0x180 mm/kasan/report.c:601
 rt6_fill_node+0x1460/0x1ac0
  inet6_rt_notify+0x13b/0x290 net/ipv6/route.c:6184
  ip6_route_mpath_notify net/ipv6/route.c:5198 [inline]
  ip6_route_multipath_add net/ipv6/route.c:5404 [inline]
  inet6_rtm_newroute+0x1d0f/0x2300 net/ipv6/route.c:5517
  rtnetlink_rcv_msg+0x885/0x1040 net/core/rtnetlink.c:6597
  netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543
  netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]
  netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367
  netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x221/0x270 net/socket.c:745
  ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584
  ___sys_sendmsg net/socket.c:2638 [inline]
  __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667
 do_syscall_64+0xf9/0x240
 entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7f73dd87dda9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f73de6550c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f73dd9ac050 RCX: 00007f73dd87dda9
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000005
RBP: 00007f73dd8ca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f73dd9ac050 R15: 00007ffdbdeb7858
 </TASK>

Allocated by task 23037:
  kasan_save_stack mm/kasan/common.c:47 [inline]
  kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
  poison_kmalloc_redzone mm/kasan/common.c:372 [inline]
  __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:389
  kasan_kmalloc include/linux/kasan.h:211 [inline]
  __do_kmalloc_node mm/slub.c:3981 [inline]
  __kmalloc+0x22e/0x490 mm/slub.c:3994
  kmalloc include/linux/slab.h:594 [inline]
  kzalloc include/linux/slab.h:711 [inline]
  fib6_info_alloc+0x2e/0xf0 net/ipv6/ip6_fib.c:155
  ip6_route_info_create+0x445/0x12b0 net/ipv6/route.c:3758
  ip6_route_multipath_add net/ipv6/route.c:5298 [inline]
  inet6_rtm_newroute+0x744/0x2300 net/ipv6/route.c:5517
  rtnetlink_rcv_msg+0x885/0x1040 net/core/rtnetlink.c:6597
  netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543
  netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]
  netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367
  netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x221/0x270 net/socket.c:745
  ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584
  ___sys_sendmsg net/socket.c:2638 [inline]
  __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667
 do_syscall_64+0xf9/0x240
 entry_SYSCALL_64_after_hwframe+0x6f/0x77

Freed by task 16:
  kasan_save_stack mm/kasan/common.c:47 [inline]
  kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
  kasan_save_free_info+0x4e/0x60 mm/kasan/generic.c:640
  poison_slab_object+0xa6/0xe0 mm/kasan/common.c:241
  __kasan_slab_free+0x34/0x70 mm/kasan/common.c:257
  kasan_slab_free include/linux/kasan.h:184 [inline]
  slab_free_hook mm/slub.c:2121 [inline]
  slab_free mm/slub.c:4299 [inline]
  kfree+0x14a/0x380 mm/slub.c:4409
  rcu_do_batch kernel/rcu/tree.c:2190 [inline]
  rcu_core+0xd76/0x1810 kernel/rcu/tree.c:2465
  __do_softirq+0x2bb/0x942 kernel/softirq.c:553

Last potentially related work creation:
  kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
  __kasan_record_aux_stack+0xae/0x100 mm/kasan/generic.c:586
  __call_rcu_common kernel/rcu/tree.c:2715 [inline]
  call_rcu+0x167/0xa80 kernel/rcu/tree.c:2829
  fib6_info_release include/net/ip6_fib.h:341 [inline]
  ip6_route_multipath_add net/ipv6/route.c:5344 [inline]
  inet6_rtm_newroute+0x114d/0x2300 net/ipv6/route.c:5517
  rtnetlink_rcv_msg+0x885/0x1040 net/core/rtnetlink.c:6597
  netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543
  netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]
  netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367
  netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x221/0x270 net/socket.c:745
  ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584
  ___sys_sendmsg net/socket.c:2638 [inline]
  __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667
 do_syscall_64+0xf9/0x240
 entry_SYSCALL_64_after_hwframe+0x6f/0x77

The buggy address belongs to the object at ffff88809a07fc00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 100 bytes inside of
 freed 512-byte region [ffff88809a07fc00, ffff88809a07fe00)

The buggy address belongs to the physical page:
page:ffffea0002681f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9a07c
head:ffffea0002681f00 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888014c41c80 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 23028, tgid 23027 (syz-executor.4), ts 2340253595219, free_ts 2339107097036
  set_page_owner include/linux/page_owner.h:31 [inline]
  post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1533
  prep_new_page mm/page_alloc.c:1540 [inline]
  get_page_from_freelist+0x33ea/0x3580 mm/page_alloc.c:3311
  __alloc_pages+0x255/0x680 mm/page_alloc.c:4567
  __alloc_pages_node include/linux/gfp.h:238 [inline]
  alloc_pages_node include/linux/gfp.h:261 [inline]
  alloc_slab_page+0x5f/0x160 mm/slub.c:2190
  allocate_slab mm/slub.c:2354 [inline]
  new_slab+0x84/0x2f0 mm/slub.c:2407
  ___slab_alloc+0xd17/0x13e0 mm/slub.c:3540
  __slab_alloc mm/slub.c:3625 [inline]
  __slab_alloc_node mm/slub.c:3678 [inline]
  slab_alloc_node mm/slub.c:3850 [inline]
  __do_kmalloc_node mm/slub.c:3980 [inline]
  __kmalloc+0x2e0/0x490 mm/slub.c:3994
  kmalloc include/linux/slab.h:594 [inline]
  kzalloc include/linux/slab.h:711 [inline]
  new_dir fs/proc/proc_sysctl.c:956 [inline]
  get_subdir fs/proc/proc_sysctl.c:1000 [inline]
  sysctl_mkdir_p fs/proc/proc_sysctl.c:1295 [inline]
  __register_sysctl_table+0xb30/0x1440 fs/proc/proc_sysctl.c:1376
  neigh_sysctl_register+0x416/0x500 net/core/neighbour.c:3859
  devinet_sysctl_register+0xaf/0x1f0 net/ipv4/devinet.c:2644
  inetdev_init+0x296/0x4d0 net/ipv4/devinet.c:286
  inetdev_event+0x338/0x15c0 net/ipv4/devinet.c:1555
  notifier_call_chain+0x18f/0x3b0 kernel/notifier.c:93
  call_netdevice_notifiers_extack net/core/dev.c:1987 [inline]
  call_netdevice_notifiers net/core/dev.c:2001 [inline]
  register_netdevice+0x15b2/0x1a20 net/core/dev.c:10340
  br_dev_newlink+0x27/0x100 net/bridge/br_netlink.c:1563
  rtnl_newlink_create net/core/rtnetlink.c:3497 [inline]
  __rtnl_newlink net/core/rtnetlink.c:3717 [inline]
  rtnl_newlink+0x158f/0x20a0 net/core/rtnetlink.c:3730
page last free pid 11583 tgid 11583 stack trace:
  reset_page_owner include/linux/page_owner.h:24 [inline]
  free_pages_prepare mm/page_alloc.c:1140 [inline]
  free_unref_page_prepare+0x968/0xa90 mm/page_alloc.c:2346
  free_unref_page+0x37/0x3f0 mm/page_alloc.c:2486
  kasan_depopulate_vmalloc_pte+0x74/0x90 mm/kasan/shadow.c:415
  apply_to_pte_range mm/memory.c:2619 [inline]
  apply_to_pmd_range mm/memory.c:2663 [inline]
  apply_to_pud_range mm/memory.c:2699 [inline]
  apply_to_p4d_range mm/memory.c:2735 [inline]
  __apply_to_page_range+0x8ec/0xe40 mm/memory.c:2769
  kasan_release_vmalloc+0x9a/0xb0 mm/kasan/shadow.c:532
  __purge_vmap_area_lazy+0x163f/0x1a10 mm/vmalloc.c:1770
  drain_vmap_area_work+0x40/0xd0 mm/vmalloc.c:1804
  process_one_work kernel/workqueue.c:2633 [inline]
  process_scheduled_works+0x913/0x1420 kernel/workqueue.c:2706
  worker_thread+0xa5f/0x1000 kernel/workqueue.c:2787
  kthread+0x2ef/0x390 kernel/kthread.c:388
  ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
  ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242

Memory state around the buggy address:
 ffff88809a07fb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88809a07fb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88809a07fc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff88809a07fc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88809a07fd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

Fixes: 3b1137fe74 ("net: ipv6: Change notifications for multipath add to RTA_MULTIPATH")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240303144801.702646-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-15 10:48:15 -04:00
Jon Maxwell
dd56c5790d ipv6: remove max_size check inline with ipv4
commit af6d10345ca76670c1b7c37799f0d5576ccef277 upstream.

In ip6_dst_gc() replace:

  if (entries > gc_thresh)

With:

  if (entries > ops->gc_thresh)

Sending Ipv6 packets in a loop via a raw socket triggers an issue where a
route is cloned by ip6_rt_cache_alloc() for each packet sent. This quickly
consumes the Ipv6 max_size threshold which defaults to 4096 resulting in
these warnings:

[1]   99.187805] dst_alloc: 7728 callbacks suppressed
[2] Route cache is full: consider increasing sysctl net.ipv6.route.max_size.
.
.
[300] Route cache is full: consider increasing sysctl net.ipv6.route.max_size.

When this happens the packet is dropped and sendto() gets a network is
unreachable error:

remaining pkt 200557 errno 101
remaining pkt 196462 errno 101
.
.
remaining pkt 126821 errno 101

Implement David Aherns suggestion to remove max_size check seeing that Ipv6
has a GC to manage memory usage. Ipv4 already does not check max_size.

Here are some memory comparisons for Ipv4 vs Ipv6 with the patch:

Test by running 5 instances of a program that sends UDP packets to a raw
socket 5000000 times. Compare Ipv4 and Ipv6 performance with a similar
program.

Ipv4:

Before test:

MemFree:        29427108 kB
Slab:             237612 kB

ip6_dst_cache       1912   2528    256   32    2 : tunables    0    0    0
xfrm_dst_cache         0      0    320   25    2 : tunables    0    0    0
ip_dst_cache        2881   3990    192   42    2 : tunables    0    0    0

During test:

MemFree:        29417608 kB
Slab:             247712 kB

ip6_dst_cache       1912   2528    256   32    2 : tunables    0    0    0
xfrm_dst_cache         0      0    320   25    2 : tunables    0    0    0
ip_dst_cache       44394  44394    192   42    2 : tunables    0    0    0

After test:

MemFree:        29422308 kB
Slab:             238104 kB

ip6_dst_cache       1912   2528    256   32    2 : tunables    0    0    0
xfrm_dst_cache         0      0    320   25    2 : tunables    0    0    0
ip_dst_cache        3048   4116    192   42    2 : tunables    0    0    0

Ipv6 with patch:

Errno 101 errors are not observed anymore with the patch.

Before test:

MemFree:        29422308 kB
Slab:             238104 kB

ip6_dst_cache       1912   2528    256   32    2 : tunables    0    0    0
xfrm_dst_cache         0      0    320   25    2 : tunables    0    0    0
ip_dst_cache        3048   4116    192   42    2 : tunables    0    0    0

During Test:

MemFree:        29431516 kB
Slab:             240940 kB

ip6_dst_cache      11980  12064    256   32    2 : tunables    0    0    0
xfrm_dst_cache         0      0    320   25    2 : tunables    0    0    0
ip_dst_cache        3048   4116    192   42    2 : tunables    0    0    0

After Test:

MemFree:        29441816 kB
Slab:             238132 kB

ip6_dst_cache       1902   2432    256   32    2 : tunables    0    0    0
xfrm_dst_cache         0      0    320   25    2 : tunables    0    0    0
ip_dst_cache        3048   4116    192   42    2 : tunables    0    0    0

Tested-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230112012532.311021-1-jmaxwell37@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Cc: "Jitindar Singh, Suraj" <surajjs@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-15 18:48:07 +01:00
Lu Wei
da26369377 ipv6: Add lwtunnel encap size of all siblings in nexthop calculation
[ Upstream commit 4cc59f386991ec9374cb4bc83dbe1c0b5a95033f ]

In function rt6_nlmsg_size(), the length of nexthop is calculated
by multipling the nexthop length of fib6_info and the number of
siblings. However if the fib6_info has no lwtunnel but the siblings
have lwtunnels, the nexthop length is less than it should be, and
it will trigger a warning in inet6_rt_notify() as follows:

WARNING: CPU: 0 PID: 6082 at net/ipv6/route.c:6180 inet6_rt_notify+0x120/0x130
......
Call Trace:
 <TASK>
 fib6_add_rt2node+0x685/0xa30
 fib6_add+0x96/0x1b0
 ip6_route_add+0x50/0xd0
 inet6_rtm_newroute+0x97/0xa0
 rtnetlink_rcv_msg+0x156/0x3d0
 netlink_rcv_skb+0x5a/0x110
 netlink_unicast+0x246/0x350
 netlink_sendmsg+0x250/0x4c0
 sock_sendmsg+0x66/0x70
 ___sys_sendmsg+0x7c/0xd0
 __sys_sendmsg+0x5d/0xb0
 do_syscall_64+0x3f/0x90
 entry_SYSCALL_64_after_hwframe+0x72/0xdc

This bug can be reproduced by script:

ip -6 addr add 2002::2/64 dev ens2
ip -6 route add 100::/64 via 2002::1 dev ens2 metric 100

for i in 10 20 30 40 50 60 70;
do
	ip link add link ens2 name ipv_$i type ipvlan
	ip -6 addr add 2002::$i/64 dev ipv_$i
	ifconfig ipv_$i up
done

for i in 10 20 30 40 50 60;
do
	ip -6 route append 100::/64 encap ip6 dst 2002::$i via 2002::1
dev ipv_$i metric 100
done

ip -6 route append 100::/64 via 2002::1 dev ipv_70 metric 100

This patch fixes it by adding nexthop_len of every siblings using
rt6_nh_nlmsg_size().

Fixes: beb1afac51 ("net: ipv6: Add support to dump multipath routes via RTA_MULTIPATH attribute")
Signed-off-by: Lu Wei <luwei32@huawei.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230222083629.335683-2-luwei32@huawei.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 16:40:12 +01:00
Zhengchao Shao
5dbb47ee89 ipv6: fix WARNING in ip6_route_net_exit_late()
[ Upstream commit 768b3c745fe5789f2430bdab02f35a9ad1148d97 ]

During the initialization of ip6_route_net_init_late(), if file
ipv6_route or rt6_stats fails to be created, the initialization is
successful by default. Therefore, the ipv6_route or rt6_stats file
doesn't be found during the remove in ip6_route_net_exit_late(). It
will cause WRNING.

The following is the stack information:
name 'rt6_stats'
WARNING: CPU: 0 PID: 9 at fs/proc/generic.c:712 remove_proc_entry+0x389/0x460
Modules linked in:
Workqueue: netns cleanup_net
RIP: 0010:remove_proc_entry+0x389/0x460
PKRU: 55555554
Call Trace:
<TASK>
ops_exit_list+0xb0/0x170
cleanup_net+0x4ea/0xb00
process_one_work+0x9bf/0x1710
worker_thread+0x665/0x1080
kthread+0x2e4/0x3a0
ret_from_fork+0x1f/0x30
</TASK>

Fixes: cdb1876192 ("[NETNS][IPV6] route6 - create route6 proc files for the namespace")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20221102020610.351330-1-shaozhengchao@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-10 18:14:20 +01:00
Kuniyuki Iwashima
a51040d4b1 nexthop: Fix data-races around nexthop_compat_mode.
[ Upstream commit bdf00bf24bef9be1ca641a6390fd5487873e0d2e ]

While reading nexthop_compat_mode, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

Fixes: 4f80116d3d ("net: ipv4: add sysctl for nexthop api compatibility mode")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-21 21:20:10 +02:00
Nicolas Dichtel
e77804158b ipv6: take care of disable_policy when restoring routes
commit 3b0dc529f56b5f2328244130683210be98f16f7f upstream.

When routes corresponding to addresses are restored by
fixup_permanent_addr(), the dst_nopolicy parameter was not set.
The typical use case is a user that configures an address on a down
interface and then put this interface up.

Let's take care of this flag in addrconf_f6i_alloc(), so that every callers
benefit ont it.

CC: stable@kernel.org
CC: David Forster <dforster@brocade.com>
Fixes: df789fe752 ("ipv6: Provide ipv6 version of "disable_policy" sysctl")
Reported-by: Siwar Zitouni <siwar.zitouni@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220623120015.32640-1-nicolas.dichtel@6wind.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-07 17:52:15 +02:00
Eric Dumazet
49516e6ed9 ipv6: make ip6_rt_gc_expire an atomic_t
[ Upstream commit 9cb7c013420f98fa6fd12fc6a5dc055170c108db ]

Reads and Writes to ip6_rt_gc_expire always have been racy,
as syzbot reported lately [1]

There is a possible risk of under-flow, leading
to unexpected high value passed to fib6_run_gc(),
although I have not observed this in the field.

Hosts hitting ip6_dst_gc() very hard are under pretty bad
state anyway.

[1]
BUG: KCSAN: data-race in ip6_dst_gc / ip6_dst_gc

read-write to 0xffff888102110744 of 4 bytes by task 13165 on cpu 1:
 ip6_dst_gc+0x1f3/0x220 net/ipv6/route.c:3311
 dst_alloc+0x9b/0x160 net/core/dst.c:86
 ip6_dst_alloc net/ipv6/route.c:344 [inline]
 icmp6_dst_alloc+0xb2/0x360 net/ipv6/route.c:3261
 mld_sendpack+0x2b9/0x580 net/ipv6/mcast.c:1807
 mld_send_cr net/ipv6/mcast.c:2119 [inline]
 mld_ifc_work+0x576/0x800 net/ipv6/mcast.c:2651
 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289
 worker_thread+0x618/0xa70 kernel/workqueue.c:2436
 kthread+0x1a9/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30

read-write to 0xffff888102110744 of 4 bytes by task 11607 on cpu 0:
 ip6_dst_gc+0x1f3/0x220 net/ipv6/route.c:3311
 dst_alloc+0x9b/0x160 net/core/dst.c:86
 ip6_dst_alloc net/ipv6/route.c:344 [inline]
 icmp6_dst_alloc+0xb2/0x360 net/ipv6/route.c:3261
 mld_sendpack+0x2b9/0x580 net/ipv6/mcast.c:1807
 mld_send_cr net/ipv6/mcast.c:2119 [inline]
 mld_ifc_work+0x576/0x800 net/ipv6/mcast.c:2651
 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289
 worker_thread+0x618/0xa70 kernel/workqueue.c:2436
 kthread+0x1a9/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30

value changed: 0x00000bb3 -> 0x00000ba9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 11607 Comm: kworker/0:21 Not tainted 5.18.0-rc1-syzkaller-00037-g42e7a03d3bad-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: mld mld_ifc_work

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220413181333.649424-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-27 13:53:51 +02:00
David Ahern
e3dd1202ab ipv6: Fix stats accounting in ip6_pkt_drop
[ Upstream commit 1158f79f82d437093aeed87d57df0548bdd68146 ]

VRF devices are the loopbacks for VRFs, and a loopback can not be
assigned to a VRF. Accordingly, the condition in ip6_pkt_drop should
be '||' not '&&'.

Fixes: 1d3fd8a10b ("vrf: Use orig netdev to count Ip6InNoRoutes and a fresh route lookup when sending dest unreach")
Reported-by: Pudak, Filip <Filip.Pudak@windriver.com>
Reported-by: Xiao, Jiguang <Jiguang.Xiao@windriver.com>
Signed-off-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220404150908.2937-1-dsahern@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-13 21:01:05 +02:00
Eric Dumazet
4cd0ef6215 ipv6: annotate accesses to fn->fn_sernum
commit aafc2e3285c2d7a79b7ee15221c19fbeca7b1509 upstream.

struct fib6_node's fn_sernum field can be
read while other threads change it.

Add READ_ONCE()/WRITE_ONCE() annotations.

Do not change existing smp barriers in fib6_get_cookie_safe()
and __fib6_update_sernum_upto_root()

syzbot reported:

BUG: KCSAN: data-race in fib6_clean_node / inet6_csk_route_socket

write to 0xffff88813df62e2c of 4 bytes by task 1920 on cpu 1:
 fib6_clean_node+0xc2/0x260 net/ipv6/ip6_fib.c:2178
 fib6_walk_continue+0x38e/0x430 net/ipv6/ip6_fib.c:2112
 fib6_walk net/ipv6/ip6_fib.c:2160 [inline]
 fib6_clean_tree net/ipv6/ip6_fib.c:2240 [inline]
 __fib6_clean_all+0x1a9/0x2e0 net/ipv6/ip6_fib.c:2256
 fib6_flush_trees+0x6c/0x80 net/ipv6/ip6_fib.c:2281
 rt_genid_bump_ipv6 include/net/net_namespace.h:488 [inline]
 addrconf_dad_completed+0x57f/0x870 net/ipv6/addrconf.c:4230
 addrconf_dad_work+0x908/0x1170
 process_one_work+0x3f6/0x960 kernel/workqueue.c:2307
 worker_thread+0x616/0xa70 kernel/workqueue.c:2454
 kthread+0x1bf/0x1e0 kernel/kthread.c:359
 ret_from_fork+0x1f/0x30

read to 0xffff88813df62e2c of 4 bytes by task 15701 on cpu 0:
 fib6_get_cookie_safe include/net/ip6_fib.h:285 [inline]
 rt6_get_cookie include/net/ip6_fib.h:306 [inline]
 ip6_dst_store include/net/ip6_route.h:234 [inline]
 inet6_csk_route_socket+0x352/0x3c0 net/ipv6/inet6_connection_sock.c:109
 inet6_csk_xmit+0x91/0x1e0 net/ipv6/inet6_connection_sock.c:121
 __tcp_transmit_skb+0x1323/0x1840 net/ipv4/tcp_output.c:1402
 tcp_transmit_skb net/ipv4/tcp_output.c:1420 [inline]
 tcp_write_xmit+0x1450/0x4460 net/ipv4/tcp_output.c:2680
 __tcp_push_pending_frames+0x68/0x1c0 net/ipv4/tcp_output.c:2864
 tcp_push+0x2d9/0x2f0 net/ipv4/tcp.c:725
 mptcp_push_release net/mptcp/protocol.c:1491 [inline]
 __mptcp_push_pending+0x46c/0x490 net/mptcp/protocol.c:1578
 mptcp_sendmsg+0x9ec/0xa50 net/mptcp/protocol.c:1764
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:643
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg net/socket.c:725 [inline]
 kernel_sendmsg+0x97/0xd0 net/socket.c:745
 sock_no_sendpage+0x84/0xb0 net/core/sock.c:3086
 inet_sendpage+0x9d/0xc0 net/ipv4/af_inet.c:834
 kernel_sendpage+0x187/0x200 net/socket.c:3492
 sock_sendpage+0x5a/0x70 net/socket.c:1007
 pipe_to_sendpage+0x128/0x160 fs/splice.c:364
 splice_from_pipe_feed fs/splice.c:418 [inline]
 __splice_from_pipe+0x207/0x500 fs/splice.c:562
 splice_from_pipe fs/splice.c:597 [inline]
 generic_splice_sendpage+0x94/0xd0 fs/splice.c:746
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:936
 splice_direct_to_actor+0x345/0x650 fs/splice.c:891
 do_splice_direct+0x106/0x190 fs/splice.c:979
 do_sendfile+0x675/0xc40 fs/read_write.c:1245
 __do_sys_sendfile64 fs/read_write.c:1310 [inline]
 __se_sys_sendfile64 fs/read_write.c:1296 [inline]
 __x64_sys_sendfile64+0x102/0x140 fs/read_write.c:1296
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000026f -> 0x00000271

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 15701 Comm: syz-executor.2 Not tainted 5.16.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

The Fixes tag I chose is probably arbitrary, I do not think
we need to backport this patch to older kernels.

Fixes: c5cff8561d ("ipv6: add rcu grace period before freeing fib6_node")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Link: https://lore.kernel.org/r/20220120174112.1126644-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-01 17:25:44 +01:00
David Ahern
498d77fc5e ipv6: Do cleanup if attribute validation fails in multipath route
[ Upstream commit 95bdba23b5b4aa75fe3e6c84335e638641c707bb ]

As Nicolas noted, if gateway validation fails walking the multipath
attribute the code should jump to the cleanup to free previously
allocated memory.

Fixes: 1ff15a710a86 ("ipv6: Check attribute length for RTA_GATEWAY when deleting multipath route")
Signed-off-by: David Ahern <dsahern@kernel.org>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20220103170555.94638-1-dsahern@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-11 15:25:01 +01:00
David Ahern
72b0d14a0a ipv6: Continue processing multipath route even if gateway attribute is invalid
[ Upstream commit e30a845b0376eb51c9c94f56bbd53b2e08ba822f ]

ip6_route_multipath_del loop continues processing the multipath
attribute even if delete of a nexthop path fails. For consistency,
do the same if the gateway attribute is invalid.

Fixes: 1ff15a710a86 ("ipv6: Check attribute length for RTA_GATEWAY when deleting multipath route")
Signed-off-by: David Ahern <dsahern@kernel.org>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20220103171911.94739-1-dsahern@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-11 15:25:01 +01:00
David Ahern
f403b5f96e lwtunnel: Validate RTA_ENCAP_TYPE attribute length
commit 8bda81a4d400cf8a72e554012f0d8c45e07a3904 upstream.

lwtunnel_valid_encap_type_attr is used to validate encap attributes
within a multipath route. Add length validation checking to the type.

lwtunnel_valid_encap_type_attr is called converting attributes to
fib{6,}_config struct which means it is used before fib_get_nhs,
ip6_route_multipath_add, and ip6_route_multipath_del - other
locations that use rtnh_ok and then nla_get_u16 on RTA_ENCAP_TYPE
attribute.

Fixes: 9ed59592e3 ("lwtunnel: fix autoload of lwt modules")

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>
2022-01-11 15:25:00 +01:00
David Ahern
48d5adb08d ipv6: Check attribute length for RTA_GATEWAY when deleting multipath route
commit 1ff15a710a862db1101b97810af14aedc835a86a upstream.

Make sure RTA_GATEWAY for IPv6 multipath route has enough bytes to hold
an IPv6 address.

Fixes: 6b9ea5a64e ("ipv6: fix multipath route replace error recovery")
Signed-off-by: David Ahern <dsahern@kernel.org>
Cc: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-11 15:25:00 +01:00
David Ahern
173bfa2782 ipv6: Check attribute length for RTA_GATEWAY in multipath route
commit 4619bcf91399f00a40885100fb61d594d8454033 upstream.

Commit referenced in the Fixes tag used nla_memcpy for RTA_GATEWAY as
does the current nla_get_in6_addr. nla_memcpy protects against accessing
memory greater than what is in the attribute, but there is no check
requiring the attribute to have an IPv6 address. Add it.

Fixes: 51ebd31815 ("ipv6: add support of equal cost multipath (ECMP)")
Signed-off-by: David Ahern <dsahern@kernel.org>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-11 15:25:00 +01:00
Nikolay Aleksandrov
3c40584595 net: ipv6: add fib6_nh_release_dsts stub
[ Upstream commit 8837cbbf854246f5f4d565f21e6baa945d37aded ]

We need a way to release a fib6_nh's per-cpu dsts when replacing
nexthops otherwise we can end up with stale per-cpu dsts which hold net
device references, so add a new IPv6 stub called fib6_nh_release_dsts.
It must be used after an RCU grace period, so no new dsts can be created
through a group's nexthop entry.
Similar to fib6_nh_release it shouldn't be used if fib6_nh_init has failed
so it doesn't need a dummy stub when IPv6 is not enabled.

Fixes: 7bf4796dd0 ("nexthops: add support for replace")
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-01 09:19:05 +01:00
Xiao Liang
8de12ad916 net: ipv4: Fix rtnexthop len when RTA_FLOW is present
[ Upstream commit 597aa16c782496bf74c5dc3b45ff472ade6cee64 ]

Multipath RTA_FLOW is embedded in nexthop. Dump it in fib_add_nexthop()
to get the length of rtnexthop correct.

Fixes: b0f6019363 ("ipv4: Refactor nexthop attributes in fib_dump_info")
Signed-off-by: Xiao Liang <shaw.leon@gmail.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>
2021-10-06 15:55:53 +02:00
Eric Dumazet
8692f0bb29 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 09:50:45 +02:00
Eric Dumazet
dced8347a7 ipv6: use siphash in rt6_exception_hash()
[ Upstream commit 4785305c05b25a242e5314cc821f54ade4c18810 ]

A group of security researchers brought to our attention
the weakness of hash function used in rt6_exception_hash()

Lets use siphash instead of Jenkins Hash, to considerably
reduce security risks.

Following patch deals with 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>
Acked-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-03 10:09:24 +02:00
Paolo Abeni
ce8fafb680 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 14:35:40 +02:00
Coco Li
0987023582 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: 706ec91916 ("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 13:39:20 +02:00
Muhammad Usama Anjum
40375bc3d0 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 08:41:57 +02:00
Daniel Borkmann
0a245acbce net: Consolidate common blackhole dst ops
[ Upstream commit c4c877b2732466b4c63217baad05c96f775912c7 ]

Move generic blackhole dst ops to the core and use them from both
ipv4_dst_blackhole_ops and ip6_dst_blackhole_ops where possible. No
functional change otherwise. We need these also in other locations
and having to define them over and over again is not great.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:32:05 +02:00
Jakub Kicinski
2295cddf99 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Minor conflicts in net/mptcp/protocol.h and
tools/testing/selftests/net/Makefile.

In both cases code was added on both sides in the same place
so just keep both.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-15 12:43:21 -07:00
Georg Kohmann
4a65dff81a net: ipv6: Discard next-hop MTU less than minimum link MTU
When a ICMPV6_PKT_TOOBIG report a next-hop MTU that is less than the IPv6
minimum link MTU, the estimated path MTU is reduced to the minimum link
MTU. This behaviour breaks TAHI IPv6 Core Conformance Test v6LC4.1.6:
Packet Too Big Less than IPv6 MTU.

Referring to RFC 8201 section 4: "If a node receives a Packet Too Big
message reporting a next-hop MTU that is less than the IPv6 minimum link
MTU, it must discard it. A node must not reduce its estimate of the Path
MTU below the IPv6 minimum link MTU on receipt of a Packet Too Big
message."

Drop the path MTU update if reported MTU is less than the minimum link MTU.

Signed-off-by: Georg Kohmann <geokohma@cisco.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-09 16:22:59 -07:00
David S. Miller
3ab0a7a0c3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Two minor conflicts:

1) net/ipv4/route.c, adding a new local variable while
   moving another local variable and removing it's
   initial assignment.

2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes.
   One pretty prints the port mode differently, whilst another
   changes the driver to try and obtain the port mode from
   the port node rather than the switch node.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-22 16:45:34 -07:00
Xu Wang
91b2c9a0fd ipv6: route: convert comma to semicolon
Replace a comma between expression statements by a semicolon.

Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-21 14:52:18 -07:00
Colin Ian King
2291267e48 ipv6: remove redundant assignment to variable err
The variable err is being initialized with a value that is never read and
it is being updated later with a new value. The initialization is redundant
and can be removed.  Also re-order variable declarations in reverse
Christmas tree ordering.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-11 14:48:25 -07:00
David S. Miller
2e7199bd77 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2020-08-04

The following pull-request contains BPF updates for your *net-next* tree.

We've added 73 non-merge commits during the last 9 day(s) which contain
a total of 135 files changed, 4603 insertions(+), 1013 deletions(-).

The main changes are:

1) Implement bpf_link support for XDP. Also add LINK_DETACH operation for the BPF
   syscall allowing processes with BPF link FD to force-detach, from Andrii Nakryiko.

2) Add BPF iterator for map elements and to iterate all BPF programs for efficient
   in-kernel inspection, from Yonghong Song and Alexei Starovoitov.

3) Separate bpf_get_{stack,stackid}() helpers for perf events in BPF to avoid
   unwinder errors, from Song Liu.

4) Allow cgroup local storage map to be shared between programs on the same
   cgroup. Also extend BPF selftests with coverage, from YiFei Zhu.

5) Add BPF exception tables to ARM64 JIT in order to be able to JIT BPF_PROBE_MEM
   load instructions, from Jean-Philippe Brucker.

6) Follow-up fixes on BPF socket lookup in combination with reuseport group
   handling. Also add related BPF selftests, from Jakub Sitnicki.

7) Allow to use socket storage in BPF_PROG_TYPE_CGROUP_SOCK-typed programs for
   socket create/release as well as bind functions, from Stanislav Fomichev.

8) Fix an info leak in xsk_getsockopt() when retrieving XDP stats via old struct
   xdp_statistics, from Peilin Ye.

9) Fix PT_REGS_RC{,_CORE}() macros in libbpf for MIPS arch, from Jerry Crunchtime.

10) Extend BPF kernel test infra with skb->family and skb->{local,remote}_ip{4,6}
    fields and allow user space to specify skb->dev via ifindex, from Dmitry Yakunin.

11) Fix a bpftool segfault due to missing program type name and make it more robust
    to prevent them in future gaps, from Quentin Monnet.

12) Consolidate cgroup helper functions across selftests and fix a v6 localhost
    resolver issue, from John Fastabend.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-03 18:27:40 -07:00
David S. Miller
bd0b33b248 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Resolved kernel/bpf/btf.c using instructions from merge commit
69138b34a7

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-02 01:02:12 -07:00
Xiyu Yang
706ec91916 ipv6: Fix nexthop refcnt leak when creating ipv6 route info
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>
2020-07-28 17:24:08 -07:00
Yonghong Song
14fc6bd6b7 bpf: Refactor bpf_iter_reg to have separate seq_info member
There is no functionality change for this patch.
Struct bpf_iter_reg is used to register a bpf_iter target,
which includes information for both prog_load, link_create
and seq_file creation.

This patch puts fields related seq_file creation into
a different structure. This will be useful for map
elements iterator where one iterator covers different
map types and different map types may have different
seq_ops, init/fini private_data function and
private_data size.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723184109.590030-1-yhs@fb.com
2020-07-25 20:16:32 -07:00
Yonghong Song
951cf368bc bpf: net: Use precomputed btf_id for bpf iterators
One additional field btf_id is added to struct
bpf_ctx_arg_aux to store the precomputed btf_ids.
The btf_id is computed at build time with
BTF_ID_LIST or BTF_ID_LIST_GLOBAL macro definitions.
All existing bpf iterators are changed to used
pre-compute btf_ids.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200720163403.1393551-1-yhs@fb.com
2020-07-21 13:26:26 -07:00
David S. Miller
71930d6102 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
All conflicts seemed rather trivial, with some guidance from
Saeed Mameed on the tc_ct.c one.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-11 00:46:00 -07:00
David Ahern
aea23c323d ipv6: Fix use of anycast address with loopback
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>
2020-07-07 13:04:16 -07:00
David Ahern
34fe5a1cf9 ipv6: fib6_select_path can not use out path for nexthop objects
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>
2020-07-06 13:24:16 -07:00
Brian Vazquez
55cced4f81 ipv6: fib6: avoid indirect calls from fib6_rule_lookup
It was reported that a considerable amount of cycles were spent on the
expensive indirect calls on fib6_rule_lookup. This patch introduces an
inline helper called pol_route_func that uses the indirect_call_wrappers
to avoid the indirect calls.

This patch saves around 50ns per call.

Performance was measured on the receiver by checking the amount of
syncookies that server was able to generate under a synflood load.

Traffic was generated using trafgen[1] which was pushing around 1Mpps on
a single queue. Receiver was using only one rx queue which help to
create a bottle neck and make the experiment rx-bounded.

These are the syncookies generated over 10s from the different runs:

Whithout the patch:
TcpExtSyncookiesSent            3553749            0.0
TcpExtSyncookiesSent            3550895            0.0
TcpExtSyncookiesSent            3553845            0.0
TcpExtSyncookiesSent            3541050            0.0
TcpExtSyncookiesSent            3539921            0.0
TcpExtSyncookiesSent            3557659            0.0
TcpExtSyncookiesSent            3526812            0.0
TcpExtSyncookiesSent            3536121            0.0
TcpExtSyncookiesSent            3529963            0.0
TcpExtSyncookiesSent            3536319            0.0

With the patch:
TcpExtSyncookiesSent            3611786            0.0
TcpExtSyncookiesSent            3596682            0.0
TcpExtSyncookiesSent            3606878            0.0
TcpExtSyncookiesSent            3599564            0.0
TcpExtSyncookiesSent            3601304            0.0
TcpExtSyncookiesSent            3609249            0.0
TcpExtSyncookiesSent            3617437            0.0
TcpExtSyncookiesSent            3608765            0.0
TcpExtSyncookiesSent            3620205            0.0
TcpExtSyncookiesSent            3601895            0.0

Without the patch the average is 354263 pkt/s or 2822 ns/pkt and with
the patch the average is 360738 pkt/s or 2772 ns/pkt which gives an
estimate of 50 ns per packet.

[1] http://netsniff-ng.org/

Changelog since v1:
 - Change ordering in the ICW (Paolo Abeni)

Cc: Luigi Rizzo <lrizzo@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Brian Vazquez <brianvv@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-23 15:11:19 -07:00
Roopa Prabhu
38428d6871 nexthop: support for fdb ecmp nexthops
This patch introduces ecmp nexthops and nexthop groups
for mac fdb entries. In subsequent patches this is used
by the vxlan driver fdb entries. The use case is
E-VPN multihoming [1,2,3] which requires bridged vxlan traffic
to be load balanced to remote switches (vteps) belonging to
the same multi-homed ethernet segment (This is analogous to
a multi-homed LAG but over vxlan).

Changes include new nexthop flag NHA_FDB for nexthops
referenced by fdb entries. These nexthops only have ip.
This patch includes appropriate checks to avoid routes
referencing such nexthops.

example:
$ip nexthop add id 12 via 172.16.1.2 fdb
$ip nexthop add id 13 via 172.16.1.3 fdb
$ip nexthop add id 102 group 12/13 fdb

$bridge fdb add 02:02:00:00:00:13 dev vxlan1000 nhid 101 self

[1] E-VPN https://tools.ietf.org/html/rfc7432
[2] E-VPN VxLAN: https://tools.ietf.org/html/rfc8365
[3] LPC talk with mention of nexthop groups for L2 ecmp
http://vger.kernel.org/lpc_net2018_talks/scaling_bridge_fdb_database_slidesV3.pdf

v4 - fixed uninitialized variable reported by kernel test robot
Reported-by: kernel test robot <rong.a.chen@intel.com>

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-22 14:00:38 -07:00
Christoph Hellwig
7c1552da90 ipv6: lift copy_from_user out of ipv6_route_ioctl
Prepare for better compat ioctl handling by moving the user copy out
of ipv6_route_ioctl.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-18 17:35:02 -07:00
David S. Miller
da07f52d3c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Move the bpf verifier trace check into the new switch statement in
HEAD.

Resolve the overlapping changes in hinic, where bug fixes overlap
the addition of VF support.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-15 13:48:59 -07:00
David S. Miller
d00f26b623 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2020-05-14

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Merged tag 'perf-for-bpf-2020-05-06' from tip tree that includes CAP_PERFMON.

2) support for narrow loads in bpf_sock_addr progs and additional
   helpers in cg-skb progs, from Andrey.

3) bpf benchmark runner, from Andrii.

4) arm and riscv JIT optimizations, from Luke.

5) bpf iterator infrastructure, from Yonghong.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-14 20:31:21 -07:00
Yonghong Song
3c32cc1bce bpf: Enable bpf_iter targets registering ctx argument types
Commit b121b341e5 ("bpf: Add PTR_TO_BTF_ID_OR_NULL
support") adds a field btf_id_or_null_non0_off to
bpf_prog->aux structure to indicate that the
first ctx argument is PTR_TO_BTF_ID reg_type and
all others are PTR_TO_BTF_ID_OR_NULL.
This approach does not really scale if we have
other different reg types in the future, e.g.,
a pointer to a buffer.

This patch enables bpf_iter targets registering ctx argument
reg types which may be different from the default one.
For example, for pointers to structures, the default reg_type
is PTR_TO_BTF_ID for tracing program. The target can register
a particular pointer type as PTR_TO_BTF_ID_OR_NULL which can
be used by the verifier to enforce accesses.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200513180221.2949882-1-yhs@fb.com
2020-05-13 12:30:50 -07:00
Yonghong Song
ab2ee4fcb9 bpf: Change func bpf_iter_unreg_target() signature
Change func bpf_iter_unreg_target() parameter from target
name to target reg_info, similar to bpf_iter_reg_target().

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200513180220.2949737-1-yhs@fb.com
2020-05-13 12:30:50 -07:00
Yonghong Song
15172a46fa bpf: net: Refactor bpf_iter target registration
Currently bpf_iter_reg_target takes parameters from target
and allocates memory to save them. This is really not
necessary, esp. in the future we may grow information
passed from targets to bpf_iter manager.

The patch refactors the code so target reg_info
becomes static and bpf_iter manager can just take
a reference to it.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200513180219.2949605-1-yhs@fb.com
2020-05-13 12:30:50 -07:00
Yonghong Song
138d0be35b net: bpf: Add netlink and ipv6_route bpf_iter targets
This patch added netlink and ipv6_route targets, using
the same seq_ops (except show() and minor changes for stop())
for /proc/net/{netlink,ipv6_route}.

The net namespace for these targets are the current net
namespace at file open stage, similar to
/proc/net/{netlink,ipv6_route} reference counting
the net namespace at seq_file open stage.

Since module is not supported for now, ipv6_route is
supported only if the IPV6 is built-in, i.e., not compiled
as a module. The restriction can be lifted once module
is properly supported for bpf_iter.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175910.2476329-1-yhs@fb.com
2020-05-09 17:05:26 -07:00
Eric Dumazet
d8882935fc ipv6: use DST_NOCOUNT in ip6_rt_pcpu_alloc()
We currently have to adjust ipv6 route gc_thresh/max_size depending
on number of cpus on a server, this makes very little sense.

If the kernels sets /proc/sys/net/ipv6/route/gc_thresh to 1024
and /proc/sys/net/ipv6/route/max_size to 4096, then we better
not track the percpu dst that our implementation uses.

Only routes not added (directly or indirectly) by the admin
should be tracked and limited.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: David Ahern <dsahern@kernel.org>
Cc: Maciej Żenczykowski <maze@google.com>
Acked-by: Wei Wang <weiwan@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-05-08 22:34:17 -07:00
Eric Dumazet
cf86a086a1 net/dst: use a smaller percpu_counter batch for dst entries accounting
percpu_counter_add() uses a default batch size which is quite big
on platforms with 256 cpus. (2*256 -> 512)

This means dst_entries_get_fast() can be off by +/- 2*(nr_cpus^2)
(131072 on servers with 256 cpus)

Reduce the batch size to something more reasonable, and
add logic to ip6_dst_gc() to call dst_entries_get_slow()
before calling the _very_ expensive fib6_run_gc() function.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-05-08 21:33:33 -07:00
Maciej Żenczykowski
09454fd0a4 Revert "ipv6: add mtu lock check in __ip6_rt_update_pmtu"
This reverts commit 19bda36c42:

| 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>
2020-05-07 17:29:12 -07:00