270 Commits

Author SHA1 Message Date
Eric Dumazet
f01e02acc5 net, neigh: clear whole pneigh_entry at alloc time
commit e195e9b5dee6459d8c8e6a314cc71a644a0537fd upstream.

Commit 2c611ad97a82 ("net, neigh: Extend neigh->flags to 32 bit
to allow for extensions") enables a new KMSAM warning [1]

I think the bug is actually older, because the following intruction
only occurred if ndm->ndm_flags had NTF_PROXY set.

	pn->flags = ndm->ndm_flags;

Let's clear all pneigh_entry fields at alloc time.

[1]
BUG: KMSAN: uninit-value in pneigh_fill_info+0x986/0xb30 net/core/neighbour.c:2593
 pneigh_fill_info+0x986/0xb30 net/core/neighbour.c:2593
 pneigh_dump_table net/core/neighbour.c:2715 [inline]
 neigh_dump_info+0x1e3f/0x2c60 net/core/neighbour.c:2832
 netlink_dump+0xaca/0x16a0 net/netlink/af_netlink.c:2265
 __netlink_dump_start+0xd1c/0xee0 net/netlink/af_netlink.c:2370
 netlink_dump_start include/linux/netlink.h:254 [inline]
 rtnetlink_rcv_msg+0x181b/0x18c0 net/core/rtnetlink.c:5534
 netlink_rcv_skb+0x447/0x800 net/netlink/af_netlink.c:2491
 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:5589
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x1095/0x1360 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x16f3/0x1870 net/netlink/af_netlink.c:1916
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg net/socket.c:724 [inline]
 sock_write_iter+0x594/0x690 net/socket.c:1057
 call_write_iter include/linux/fs.h:2162 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0x1318/0x2030 fs/read_write.c:590
 ksys_write+0x28c/0x520 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0xdb/0x120 fs/read_write.c:652
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Uninit was created at:
 slab_post_alloc_hook mm/slab.h:524 [inline]
 slab_alloc_node mm/slub.c:3251 [inline]
 slab_alloc mm/slub.c:3259 [inline]
 __kmalloc+0xc3c/0x12d0 mm/slub.c:4437
 kmalloc include/linux/slab.h:595 [inline]
 pneigh_lookup+0x60f/0xd70 net/core/neighbour.c:766
 arp_req_set_public net/ipv4/arp.c:1016 [inline]
 arp_req_set+0x430/0x10a0 net/ipv4/arp.c:1032
 arp_ioctl+0x8d4/0xb60 net/ipv4/arp.c:1232
 inet_ioctl+0x4ef/0x820 net/ipv4/af_inet.c:947
 sock_do_ioctl net/socket.c:1118 [inline]
 sock_ioctl+0xa3f/0x13e0 net/socket.c:1235
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0x2df/0x4a0 fs/ioctl.c:860
 __x64_sys_ioctl+0xd8/0x110 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x44/0xae

CPU: 1 PID: 20001 Comm: syz-executor.0 Not tainted 5.16.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: 62dd93181aaa ("[IPV6] NDISC: Set per-entry is_router flag in Proxy NA.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Roopa Prabhu <roopa@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20211206165329.1049835-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 10:04:49 +01:00
Tong Zhu
52d3add40f neighbour: Disregard DEAD dst in neigh_update
[ Upstream commit d47ec7a0a7271dda08932d6208e4ab65ab0c987c ]

After a short network outage, the dst_entry is timed out and put
in DST_OBSOLETE_DEAD. We are in this code because arp reply comes
from this neighbour after network recovers. There is a potential
race condition that dst_entry is still in DST_OBSOLETE_DEAD.
With that, another neighbour lookup causes more harm than good.

In best case all packets in arp_queue are lost. This is
counterproductive to the original goal of finding a better path
for those packets.

I observed a worst case with 4.x kernel where a dst_entry in
DST_OBSOLETE_DEAD state is associated with loopback net_device.
It leads to an ethernet header with all zero addresses.
A packet with all zero source MAC address is quite deadly with
mac80211, ath9k and 802.11 block ack.  It fails
ieee80211_find_sta_by_ifaddr in ath9k (xmit.c). Ath9k flushes tx
queue (ath_tx_complete_aggr). BAW (block ack window) is not
updated. BAW logic is damaged and ath9k transmission is disabled.

Signed-off-by: Tong Zhu <zhutong@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-28 12:07:15 +02:00
Vasily Averin
d2ce05d7a1 neigh_stat_seq_next() should increase position index
[ Upstream commit 1e3f9f073c47bee7c23e77316b07bc12338c5bba ]

if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 20:40:04 +02:00
Eric Dumazet
ce55641144 net: neigh: use long type to store jiffies delta
[ Upstream commit 9d027e3a83f39b819e908e4e09084277a2e45e95 ]

A difference of two unsigned long needs long storage.

Fixes: c7fb64db001f ("[NETLINK]: Neighbour table configuration and statistics via rtnetlink")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-29 10:24:35 +01:00
Eric Dumazet
36d6d826d5 net: add annotations on hh->hh_len lockless accesses
[ Upstream commit c305c6ae79e2ce20c22660ceda94f0d86d639a82 ]

KCSAN reported a data-race [1]

While we can use READ_ONCE() on the read sides,
we need to make sure hh->hh_len is written last.

[1]

BUG: KCSAN: data-race in eth_header_cache / neigh_resolve_output

write to 0xffff8880b9dedcb8 of 4 bytes by task 29760 on cpu 0:
 eth_header_cache+0xa9/0xd0 net/ethernet/eth.c:247
 neigh_hh_init net/core/neighbour.c:1463 [inline]
 neigh_resolve_output net/core/neighbour.c:1480 [inline]
 neigh_resolve_output+0x415/0x470 net/core/neighbour.c:1470
 neigh_output include/net/neighbour.h:511 [inline]
 ip6_finish_output2+0x7a2/0xec0 net/ipv6/ip6_output.c:116
 __ip6_finish_output net/ipv6/ip6_output.c:142 [inline]
 __ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127
 ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ndisc_send_skb+0x459/0x5f0 net/ipv6/ndisc.c:505
 ndisc_send_ns+0x207/0x430 net/ipv6/ndisc.c:647
 rt6_probe_deferred+0x98/0xf0 net/ipv6/route.c:615
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

read to 0xffff8880b9dedcb8 of 4 bytes by task 29572 on cpu 1:
 neigh_resolve_output net/core/neighbour.c:1479 [inline]
 neigh_resolve_output+0x113/0x470 net/core/neighbour.c:1470
 neigh_output include/net/neighbour.h:511 [inline]
 ip6_finish_output2+0x7a2/0xec0 net/ipv6/ip6_output.c:116
 __ip6_finish_output net/ipv6/ip6_output.c:142 [inline]
 __ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127
 ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ndisc_send_skb+0x459/0x5f0 net/ipv6/ndisc.c:505
 ndisc_send_ns+0x207/0x430 net/ipv6/ndisc.c:647
 rt6_probe_deferred+0x98/0xf0 net/ipv6/route.c:615
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 29572 Comm: kworker/1:4 Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events rt6_probe_deferred

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-12 11:24:19 +01:00
Konstantin Khlebnikov
41feb09d50 net/core/neighbour: fix kmemleak minimal reference count for hash tables
[ Upstream commit 01b833ab44c9e484060aad72267fc7e71beb559b ]

This should be 1 for normal allocations, 0 disables leak reporting.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reported-by: Cong Wang <xiyou.wangcong@gmail.com>
Fixes: 85704cb8dcfd ("net/core/neighbour: tell kmemleak about hash tables")
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-05 15:35:09 +01:00
Konstantin Khlebnikov
4f4594adee net/core/neighbour: tell kmemleak about hash tables
[ Upstream commit 85704cb8dcfd88d351bfc87faaeba1c8214f3177 ]

This fixes false-positive kmemleak reports about leaked neighbour entries:

unreferenced object 0xffff8885c6e4d0a8 (size 1024):
  comm "softirq", pid 0, jiffies 4294922664 (age 167640.804s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 20 2c f3 83 ff ff ff ff  ........ ,......
    08 c0 ef 5f 84 88 ff ff 01 8c 7d 02 01 00 00 00  ..._......}.....
  backtrace:
    [<00000000748509fe>] ip6_finish_output2+0x887/0x1e40
    [<0000000036d7a0d8>] ip6_output+0x1ba/0x600
    [<0000000027ea7dba>] ip6_send_skb+0x92/0x2f0
    [<00000000d6e2111d>] udp_v6_send_skb.isra.24+0x680/0x15e0
    [<000000000668a8be>] udpv6_sendmsg+0x18c9/0x27a0
    [<000000004bd5fa90>] sock_sendmsg+0xb3/0xf0
    [<000000008227b29f>] ___sys_sendmsg+0x745/0x8f0
    [<000000008698009d>] __sys_sendmsg+0xde/0x170
    [<00000000889dacf1>] do_syscall_64+0x9b/0x400
    [<0000000081cdb353>] entry_SYSCALL_64_after_hwframe+0x49/0xbe
    [<000000005767ed39>] 0xffffffffffffffff

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-05 15:35:07 +01:00
Lorenzo Bianconi
4ebefd396d net: neigh: fix multiple neigh timer scheduling
[ Upstream commit 071c37983d99da07797294ea78e9da1a6e287144 ]

Neigh timer can be scheduled multiple times from userspace adding
multiple neigh entries and forcing the neigh timer scheduling passing
NTF_USE in the netlink requests.
This will result in a refcount leak and in the following dump stack:

[   32.465295] NEIGH: BUG, double timer add, state is 8
[   32.465308] CPU: 0 PID: 416 Comm: double_timer_ad Not tainted 5.2.0+ #65
[   32.465311] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.12.0-2.fc30 04/01/2014
[   32.465313] Call Trace:
[   32.465318]  dump_stack+0x7c/0xc0
[   32.465323]  __neigh_event_send+0x20c/0x880
[   32.465326]  ? ___neigh_create+0x846/0xfb0
[   32.465329]  ? neigh_lookup+0x2a9/0x410
[   32.465332]  ? neightbl_fill_info.constprop.0+0x800/0x800
[   32.465334]  neigh_add+0x4f8/0x5e0
[   32.465337]  ? neigh_xmit+0x620/0x620
[   32.465341]  ? find_held_lock+0x85/0xa0
[   32.465345]  rtnetlink_rcv_msg+0x204/0x570
[   32.465348]  ? rtnl_dellink+0x450/0x450
[   32.465351]  ? mark_held_locks+0x90/0x90
[   32.465354]  ? match_held_lock+0x1b/0x230
[   32.465357]  netlink_rcv_skb+0xc4/0x1d0
[   32.465360]  ? rtnl_dellink+0x450/0x450
[   32.465363]  ? netlink_ack+0x420/0x420
[   32.465366]  ? netlink_deliver_tap+0x115/0x560
[   32.465369]  ? __alloc_skb+0xc9/0x2f0
[   32.465372]  netlink_unicast+0x270/0x330
[   32.465375]  ? netlink_attachskb+0x2f0/0x2f0
[   32.465378]  netlink_sendmsg+0x34f/0x5a0
[   32.465381]  ? netlink_unicast+0x330/0x330
[   32.465385]  ? move_addr_to_kernel.part.0+0x20/0x20
[   32.465388]  ? netlink_unicast+0x330/0x330
[   32.465391]  sock_sendmsg+0x91/0xa0
[   32.465394]  ___sys_sendmsg+0x407/0x480
[   32.465397]  ? copy_msghdr_from_user+0x200/0x200
[   32.465401]  ? _raw_spin_unlock_irqrestore+0x37/0x40
[   32.465404]  ? lockdep_hardirqs_on+0x17d/0x250
[   32.465407]  ? __wake_up_common_lock+0xcb/0x110
[   32.465410]  ? __wake_up_common+0x230/0x230
[   32.465413]  ? netlink_bind+0x3e1/0x490
[   32.465416]  ? netlink_setsockopt+0x540/0x540
[   32.465420]  ? __fget_light+0x9c/0xf0
[   32.465423]  ? sockfd_lookup_light+0x8c/0xb0
[   32.465426]  __sys_sendmsg+0xa5/0x110
[   32.465429]  ? __ia32_sys_shutdown+0x30/0x30
[   32.465432]  ? __fd_install+0xe1/0x2c0
[   32.465435]  ? lockdep_hardirqs_off+0xb5/0x100
[   32.465438]  ? mark_held_locks+0x24/0x90
[   32.465441]  ? do_syscall_64+0xf/0x270
[   32.465444]  do_syscall_64+0x63/0x270
[   32.465448]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fix the issue unscheduling neigh_timer if selected entry is in 'IN_TIMER'
receiving a netlink request with NTF_USE flag set

Reported-by: Marek Majkowski <marek@cloudflare.com>
Fixes: 0c5c2d308906 ("neigh: Allow for user space users of the neighbour table")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
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>
2019-08-04 09:33:33 +02:00
Eric Dumazet
c55ce1da3d neigh: fix use-after-free read in pneigh_get_next
[ Upstream commit f3e92cb8e2eb8c27d109e6fd73d3a69a8c09e288 ]

Nine years ago, I added RCU handling to neighbours, not pneighbours.
(pneigh are not commonly used)

Unfortunately I missed that /proc dump operations would use a
common entry and exit point : neigh_seq_start() and neigh_seq_stop()

We need to read_lock(tbl->lock) or risk use-after-free while
iterating the pneigh structures.

We might later convert pneigh to RCU and revert this patch.

sysbot reported :

BUG: KASAN: use-after-free in pneigh_get_next.isra.0+0x24b/0x280 net/core/neighbour.c:3158
Read of size 8 at addr ffff888097f2a700 by task syz-executor.0/9825

CPU: 1 PID: 9825 Comm: syz-executor.0 Not tainted 5.2.0-rc4+ #32
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
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:188
 __kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 kasan_report+0x12/0x20 mm/kasan/common.c:614
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132
 pneigh_get_next.isra.0+0x24b/0x280 net/core/neighbour.c:3158
 neigh_seq_next+0xdb/0x210 net/core/neighbour.c:3240
 seq_read+0x9cf/0x1110 fs/seq_file.c:258
 proc_reg_read+0x1fc/0x2c0 fs/proc/inode.c:221
 do_loop_readv_writev fs/read_write.c:714 [inline]
 do_loop_readv_writev fs/read_write.c:701 [inline]
 do_iter_read+0x4a4/0x660 fs/read_write.c:935
 vfs_readv+0xf0/0x160 fs/read_write.c:997
 kernel_readv fs/splice.c:359 [inline]
 default_file_splice_read+0x475/0x890 fs/splice.c:414
 do_splice_to+0x127/0x180 fs/splice.c:877
 splice_direct_to_actor+0x2d2/0x970 fs/splice.c:954
 do_splice_direct+0x1da/0x2a0 fs/splice.c:1063
 do_sendfile+0x597/0xd00 fs/read_write.c:1464
 __do_sys_sendfile64 fs/read_write.c:1525 [inline]
 __se_sys_sendfile64 fs/read_write.c:1511 [inline]
 __x64_sys_sendfile64+0x1dd/0x220 fs/read_write.c:1511
 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4592c9
Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f4aab51dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000004592c9
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000246 R12: 00007f4aab51e6d4
R13: 00000000004c689d R14: 00000000004db828 R15: 00000000ffffffff

Allocated by task 9827:
 save_stack+0x23/0x90 mm/kasan/common.c:71
 set_track mm/kasan/common.c:79 [inline]
 __kasan_kmalloc mm/kasan/common.c:489 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:503
 __do_kmalloc mm/slab.c:3660 [inline]
 __kmalloc+0x15c/0x740 mm/slab.c:3669
 kmalloc include/linux/slab.h:552 [inline]
 pneigh_lookup+0x19c/0x4a0 net/core/neighbour.c:731
 arp_req_set_public net/ipv4/arp.c:1010 [inline]
 arp_req_set+0x613/0x720 net/ipv4/arp.c:1026
 arp_ioctl+0x652/0x7f0 net/ipv4/arp.c:1226
 inet_ioctl+0x2a0/0x340 net/ipv4/af_inet.c:926
 sock_do_ioctl+0xd8/0x2f0 net/socket.c:1043
 sock_ioctl+0x3ed/0x780 net/socket.c:1194
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:696
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 9824:
 save_stack+0x23/0x90 mm/kasan/common.c:71
 set_track mm/kasan/common.c:79 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459
 __cache_free mm/slab.c:3432 [inline]
 kfree+0xcf/0x220 mm/slab.c:3755
 pneigh_ifdown_and_unlock net/core/neighbour.c:812 [inline]
 __neigh_ifdown+0x236/0x2f0 net/core/neighbour.c:356
 neigh_ifdown+0x20/0x30 net/core/neighbour.c:372
 arp_ifdown+0x1d/0x21 net/ipv4/arp.c:1274
 inetdev_destroy net/ipv4/devinet.c:319 [inline]
 inetdev_event+0xa14/0x11f0 net/ipv4/devinet.c:1544
 notifier_call_chain+0xc2/0x230 kernel/notifier.c:95
 __raw_notifier_call_chain kernel/notifier.c:396 [inline]
 raw_notifier_call_chain+0x2e/0x40 kernel/notifier.c:403
 call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1749
 call_netdevice_notifiers_extack net/core/dev.c:1761 [inline]
 call_netdevice_notifiers net/core/dev.c:1775 [inline]
 rollback_registered_many+0x9b9/0xfc0 net/core/dev.c:8178
 rollback_registered+0x109/0x1d0 net/core/dev.c:8220
 unregister_netdevice_queue net/core/dev.c:9267 [inline]
 unregister_netdevice_queue+0x1ee/0x2c0 net/core/dev.c:9260
 unregister_netdevice include/linux/netdevice.h:2631 [inline]
 __tun_detach+0xd8a/0x1040 drivers/net/tun.c:724
 tun_detach drivers/net/tun.c:741 [inline]
 tun_chr_close+0xe0/0x180 drivers/net/tun.c:3451
 __fput+0x2ff/0x890 fs/file_table.c:280
 ____fput+0x16/0x20 fs/file_table.c:313
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:185 [inline]
 exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:168
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:279 [inline]
 do_syscall_64+0x58e/0x680 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff888097f2a700
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 0 bytes inside of
 64-byte region [ffff888097f2a700, ffff888097f2a740)
The buggy address belongs to the page:
page:ffffea00025fca80 refcount:1 mapcount:0 mapping:ffff8880aa400340 index:0x0
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea000250d548 ffffea00025726c8 ffff8880aa400340
raw: 0000000000000000 ffff888097f2a000 0000000100000020 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888097f2a600: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
 ffff888097f2a680: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff888097f2a700: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                   ^
 ffff888097f2a780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888097f2a800: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc

Fixes: 767e97e1e0db ("neigh: RCU conversion of struct neighbour")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-22 08:17:22 +02:00
David Ahern
86e00b7405 neighbor: Call __ipv4_neigh_lookup_noref in neigh_xmit
[ Upstream commit 4b2a2bfeb3f056461a90bd621e8bd7d03fa47f60 ]

Commit cd9ff4de0107 changed the key for IFF_POINTOPOINT devices to
INADDR_ANY but neigh_xmit which is used for MPLS encapsulations was not
updated to use the altered key. The result is that every packet Tx does
a lookup on the gateway address which does not find an entry, a new one
is created only to find the existing one in the table right before the
insert since arp_constructor was updated to reset the primary key. This
is seen in the allocs and destroys counters:
    ip -s -4 ntable show | head -10 | grep alloc

which increase for each packet showing the unnecessary overhread.

Fix by having neigh_xmit use __ipv4_neigh_lookup_noref for NEIGH_ARP_TABLE.

Fixes: cd9ff4de0107 ("ipv4: Make neigh lookup keys for loopback/point-to-point devices be INADDR_ANY")
Reported-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-11 12:22:46 +02:00
Vasily Khoruzhick
e68a49c769 neighbour: confirm neigh entries when ARP packet is received
[ Upstream commit f0e0d04413fcce9bc76388839099aee93cd0d33b ]

Update 'confirmed' timestamp when ARP packet is received. It shouldn't
affect locktime logic and anyway entry can be confirmed by any higher-layer
protocol. Thus it makes sense to confirm it when ARP packet is received.

Fixes: 77d7123342dc ("neighbour: update neigh timestamps iff update is effective")
Signed-off-by: Vasily Khoruzhick <vasilykh@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-29 03:07:33 -07:00
Wolfgang Bumiller
581cb195c5 net: fix deadlock while clearing neighbor proxy table
[ Upstream commit 53b76cdf7e8fecec1d09e38aad2f8579882591a8 ]

When coming from ndisc_netdev_event() in net/ipv6/ndisc.c,
neigh_ifdown() is called with &nd_tbl, locking this while
clearing the proxy neighbor entries when eg. deleting an
interface. Calling the table's pndisc_destructor() with the
lock still held, however, can cause a deadlock: When a
multicast listener is available an IGMP packet of type
ICMPV6_MGM_REDUCTION may be sent out. When reaching
ip6_finish_output2(), if no neighbor entry for the target
address is found, __neigh_create() is called with &nd_tbl,
which it'll want to lock.

Move the elements into their own list, then unlock the table
and perform the destruction.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199289
Fixes: 6fd6ce2056de ("ipv6: Do not depend on rt->n in ip6_finish_output2().")
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29 11:32:02 +02:00
Eric Dumazet
0e770d2927 net: validate attribute sizes in neigh_dump_table()
[ Upstream commit 7dd07c143a4b54d050e748bee4b4b9e94a7b1744 ]

Since neigh_dump_table() calls nlmsg_parse() without giving policy
constraints, attributes can have arbirary size that we must validate

Reported by syzbot/KMSAN :

BUG: KMSAN: uninit-value in neigh_master_filtered net/core/neighbour.c:2292 [inline]
BUG: KMSAN: uninit-value in neigh_dump_table net/core/neighbour.c:2348 [inline]
BUG: KMSAN: uninit-value in neigh_dump_info+0x1af0/0x2250 net/core/neighbour.c:2438
CPU: 1 PID: 3575 Comm: syzkaller268891 Not tainted 4.16.0+ #83
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:53
 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676
 neigh_master_filtered net/core/neighbour.c:2292 [inline]
 neigh_dump_table net/core/neighbour.c:2348 [inline]
 neigh_dump_info+0x1af0/0x2250 net/core/neighbour.c:2438
 netlink_dump+0x9ad/0x1540 net/netlink/af_netlink.c:2225
 __netlink_dump_start+0x1167/0x12a0 net/netlink/af_netlink.c:2322
 netlink_dump_start include/linux/netlink.h:214 [inline]
 rtnetlink_rcv_msg+0x1435/0x1560 net/core/rtnetlink.c:4598
 netlink_rcv_skb+0x355/0x5f0 net/netlink/af_netlink.c:2447
 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4653
 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
 netlink_unicast+0x1672/0x1750 net/netlink/af_netlink.c:1337
 netlink_sendmsg+0x1048/0x1310 net/netlink/af_netlink.c:1900
 sock_sendmsg_nosec net/socket.c:630 [inline]
 sock_sendmsg net/socket.c:640 [inline]
 ___sys_sendmsg+0xec0/0x1310 net/socket.c:2046
 __sys_sendmsg net/socket.c:2080 [inline]
 SYSC_sendmsg+0x2a3/0x3d0 net/socket.c:2091
 SyS_sendmsg+0x54/0x80 net/socket.c:2087
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x43fed9
RSP: 002b:00007ffddbee2798 EFLAGS: 00000213 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fed9
RDX: 0000000000000000 RSI: 0000000020005000 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000213 R12: 0000000000401800
R13: 0000000000401890 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188
 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314
 kmsan_slab_alloc+0x11/0x20 mm/kmsan/kmsan.c:321
 slab_post_alloc_hook mm/slab.h:445 [inline]
 slab_alloc_node mm/slub.c:2737 [inline]
 __kmalloc_node_track_caller+0xaed/0x11c0 mm/slub.c:4369
 __kmalloc_reserve net/core/skbuff.c:138 [inline]
 __alloc_skb+0x2cf/0x9f0 net/core/skbuff.c:206
 alloc_skb include/linux/skbuff.h:984 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1183 [inline]
 netlink_sendmsg+0x9a6/0x1310 net/netlink/af_netlink.c:1875
 sock_sendmsg_nosec net/socket.c:630 [inline]
 sock_sendmsg net/socket.c:640 [inline]
 ___sys_sendmsg+0xec0/0x1310 net/socket.c:2046
 __sys_sendmsg net/socket.c:2080 [inline]
 SYSC_sendmsg+0x2a3/0x3d0 net/socket.c:2091
 SyS_sendmsg+0x54/0x80 net/socket.c:2087
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2

Fixes: 21fdd092acc7 ("net: Add support for filtering neigh dump by master device")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: David Ahern <dsa@cumulusnetworks.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-29 11:32:00 +02:00
Ihar Hrachyshka
2c2605209a neighbour: update neigh timestamps iff update is effective
[ Upstream commit 77d7123342dcf6442341b67816321d71da8b2b16 ]

It's a common practice to send gratuitous ARPs after moving an
IP address to another device to speed up healing of a service. To
fulfill service availability constraints, the timing of network peers
updating their caches to point to a new location of an IP address can be
particularly important.

Sometimes neigh_update calls won't touch neither lladdr nor state, for
example if an update arrives in locktime interval. The neigh->updated
value is tested by the protocol specific neigh code, which in turn
will influence whether NEIGH_UPDATE_F_OVERRIDE gets set in the
call to neigh_update() or not. As a result, we may effectively ignore
the update request, bailing out of touching the neigh entry, except that
we still bump its timestamps inside neigh_update.

This may be a problem for updates arriving in quick succession. For
example, consider the following scenario:

A service is moved to another device with its IP address. The new device
sends three gratuitous ARP requests into the network with ~1 seconds
interval between them. Just before the first request arrives to one of
network peer nodes, its neigh entry for the IP address transitions from
STALE to DELAY.  This transition, among other things, updates
neigh->updated. Once the kernel receives the first gratuitous ARP, it
ignores it because its arrival time is inside the locktime interval. The
kernel still bumps neigh->updated. Then the second gratuitous ARP
request arrives, and it's also ignored because it's still in the (new)
locktime interval. Same happens for the third request. The node
eventually heals itself (after delay_first_probe_time seconds since the
initial transition to DELAY state), but it just wasted some time and
require a new ARP request/reply round trip. This unfortunate behaviour
both puts more load on the network, as well as reduces service
availability.

This patch changes neigh_update so that it bumps neigh->updated (as well
as neigh->confirmed) only once we are sure that either lladdr or entry
state will change). In the scenario described above, it means that the
second gratuitous ARP request will actually update the entry lladdr.

Ideally, we would update the neigh entry on the very first gratuitous
ARP request. The locktime mechanism is designed to ignore ARP updates in
a short timeframe after a previous ARP update was honoured by the kernel
layer. This would require tracking timestamps for state transitions
separately from timestamps when actual updates are received. This would
probably involve changes in neighbour struct. Therefore, the patch
doesn't tackle the issue of the first gratuitous APR ignored, leaving
it for a follow-up.

Signed-off-by: Ihar Hrachyshka <ihrachys@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-13 19:47:59 +02:00
Jim Westfall
014510b117 net: Allow neigh contructor functions ability to modify the primary_key
[ Upstream commit 096b9854c04df86f03b38a97d40b6506e5730919 ]

Use n->primary_key instead of pkey to account for the possibility that a neigh
constructor function may have modified the primary_key value.

Signed-off-by: Jim Westfall <jwestfall@surrealistic.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-31 12:55:55 +01:00
Eric Dumazet
4f99161f2e net: neigh: guard against NULL solicit() method
[ Upstream commit 48481c8fa16410ffa45939b13b6c53c2ca609e5f ]

Dmitry posted a nice reproducer of a bug triggering in neigh_probe()
when dereferencing a NULL neigh->ops->solicit method.

This can happen for arp_direct_ops/ndisc_direct_ops and similar,
which can be used for NUD_NOARP neighbours (created when dev->header_ops
is NULL). Admin can then force changing nud_state to some other state
that would fire neigh timer.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-03 08:36:34 -07:00
Marcus Huewe
6c854afc53 net: neigh: Fix netevent NETEVENT_DELAY_PROBE_TIME_UPDATE notification
[ Upstream commit 7627ae6030f56a9a91a5b3867b21f35d79c16e64 ]

When setting a neigh related sysctl parameter, we always send a
NETEVENT_DELAY_PROBE_TIME_UPDATE netevent. For instance, when
executing

	sysctl net.ipv6.neigh.wlp3s0.retrans_time_ms=2000

a NETEVENT_DELAY_PROBE_TIME_UPDATE netevent is generated.

This is caused by commit 2a4501ae18b5 ("neigh: Send a
notification when DELAY_PROBE_TIME changes"). According to the
commit's description, it was intended to generate such an event
when setting the "delay_first_probe_time" sysctl parameter.

In order to fix this, only generate this event when actually
setting the "delay_first_probe_time" sysctl parameter. This fix
should not have any unintended side-effects, because all but one
registered netevent callbacks check for other netevent event
types (the registered callbacks were obtained by grepping for
"register_netevent_notifier"). The only callback that uses the
NETEVENT_DELAY_PROBE_TIME_UPDATE event is
mlxsw_sp_router_netevent_event() (in
drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c): in case
of this event, it only accesses the DELAY_PROBE_TIME of the
passed neigh_parms.

Fixes: 2a4501ae18b5 ("neigh: Send a notification when DELAY_PROBE_TIME changes")
Signed-off-by: Marcus Huewe <suse-tux@gmx.de>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-26 11:10:50 +01:00
Julian Anastasov
0e7bbcc104 neigh: allow admin to set NUD_STALE
Admin should be able to set any state. Currently, this fails
when lladdr is not changed and state is changed from
NUD_CONNECTED to NUD_STALE:

ip neigh add 192.168.8.1 lladdr 00:11:22:33:44:55 nud perm dev wlan0
ip neigh show to 192.168.8.1
192.168.8.1 dev wlan0 lladdr 00:11:22:33:44:55 PERMANENT
ip neigh change 192.168.8.1 lladdr 00:11:22:33:44:55 nud stale dev wlan0
ip neigh show to 192.168.8.1
192.168.8.1 dev wlan0 lladdr 00:11:22:33:44:55 PERMANENT

Problem may be from 2.1.X days.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Reviewed-by: Chunhui He <hchunhui@mail.ustc.edu.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-08 15:36:38 -07:00
He Chunhui
d1c2b5010d net: neigh: disallow transition to NUD_STALE if lladdr is unchanged in neigh_update()
NUD_STALE is used when the caller(e.g. arp_process()) can't guarantee
neighbour reachability. If the entry was NUD_VALID and lladdr is unchanged,
the entry state should not be changed.

Currently the code puts an extra "NUD_CONNECTED" condition. So if old state
was NUD_DELAY or NUD_PROBE (they are NUD_VALID but not NUD_CONNECTED), the
state can be changed to NUD_STALE.

This may cause problem. Because NUD_STALE lladdr doesn't guarantee
reachability, when we send traffic, the state will be changed to
NUD_DELAY. In normal case, if we get no confirmation (by dst_confirm()),
we will change the state to NUD_PROBE and send probe traffic. But now the
state may be reset to NUD_STALE again(e.g. by broadcast ARP packets),
so the probe traffic will not be sent. This situation may happen again and
again, and packets will be sent to an non-reachable lladdr forever.

The fix is to remove the "NUD_CONNECTED" condition. After that the
"NEIGH_UPDATE_F_WEAK_OVERRIDE" condition (used by IPv6) in that branch will
be redundant, so remove it.

This change may increase probe traffic, but it's essential since NUD_STALE
lladdr is unreliable. To ensure correctness, we prefer to resolve lladdr,
when we can't get confirmation, even while remote packets try to set
NUD_STALE state.

Signed-off-by: Chunhui He <hchunhui@mail.ustc.edu.cn>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-26 14:25:20 -07:00
Ido Schimmel
2a4501ae18 neigh: Send a notification when DELAY_PROBE_TIME changes
When the data plane is offloaded the traffic doesn't go through the
networking stack. Therefore, after first resolving a neighbour the NUD
state machine will transition it from REACHABLE to STALE until it's
finally deleted by the garbage collector.

To prevent such situations the offloading driver should notify the NUD
state machine on any neighbours that were recently used. The driver's
polling interval should be set so that the NUD state machine can
function as if the traffic wasn't offloaded.

Currently, there are no in-tree drivers that can report confirmation for
a neighbour, but only 'used' indication. Therefore, the polling interval
should be set according to DELAY_FIRST_PROBE_TIME, as a neighbour will
transition from REACHABLE state to DELAY (instead of STALE) if "a packet
was sent within the last DELAY_FIRST_PROBE_TIME seconds" (RFC 4861).

Send a netevent whenever the DELAY_FIRST_PROBE_TIME changes - either via
netlink or sysctl - so that offloading drivers can correctly set their
polling interval.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-05 09:06:29 -07:00
Jiri Pirko
503eebc265 net: add dev arg to ndo_neigh_construct/destroy
As the following patch will allow upper devices to follow the call down
lower devices, we need to add dev here and not rely on n->dev.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-05 09:06:28 -07:00
David Barroso
b560f03ddf neigh: Explicitly declare RCU-bh read side critical section in neigh_xmit()
neigh_xmit() expects to be called inside an RCU-bh read side critical
section, and while one of its two current callers gets this right, the
other one doesn't.

More specifically, neigh_xmit() has two callers, mpls_forward() and
mpls_output(), and while both callers call neigh_xmit() under
rcu_read_lock(), this provides sufficient protection for neigh_xmit()
only in the case of mpls_forward(), as that is always called from
softirq context and therefore doesn't need explicit BH protection,
while mpls_output() can be called from process context with softirqs
enabled.

When mpls_output() is called from process context, with softirqs
enabled, we can be preempted by a softirq at any time, and RCU-bh
considers the completion of a softirq as signaling the end of any
pending read-side critical sections, so if we do get a softirq
while we are in the part of neigh_xmit() that expects to be run inside
an RCU-bh read side critical section, we can end up with an unexpected
RCU grace period running right in the middle of that critical section,
making things go boom.

This patch fixes this impedance mismatch in the callee, by making
neigh_xmit() always take rcu_read_{,un}lock_bh() around the code that
expects to be treated as an RCU-bh read side critical section, as this
seems a safer option than fixing it in the callers.

Fixes: 4fd3d7d9e868f ("neigh: Add helper function neigh_xmit")
Signed-off-by: David Barroso <dbarroso@fastly.com>
Signed-off-by: Lennert Buytenhek <lbuytenhek@fastly.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-29 07:58:28 -04:00
Nicolas Dichtel
b676338fb3 neigh: align nlattr properly when needed
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-26 12:00:49 -04:00
Nicolas Dichtel
2175d87cc3 libnl: nla_put_msecs(): align on a 64-bit area
nla_data() is now aligned on a 64-bit area.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-23 20:13:24 -04:00
Konstantin Khlebnikov
6adc5fd6a1 net/neighbour: fix crash at dumping device-agnostic proxy entries
Proxy entries could have null pointer to net-device.

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Fixes: 84920c1420e2 ("net: Allow ipv6 proxies and arp proxies be shown with iproute2")
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-03 00:07:51 -05:00
Martin Zhang
19125c1a4f net: use skb_clone to avoid alloc_pages failure.
1. new skb only need dst and ip address(v4 or v6).
2. skb_copy may need high order pages, which is very rare on long running server.

Signed-off-by: Junwei Zhang <linggao.zjw@alibaba-inc.com>
Signed-off-by: Martin Zhang <martinbj2008@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-17 15:25:44 -05:00
David Ahern
16660f0bd9 net: Add support for filtering neigh dump by device index
Add support for filtering neighbor dumps by device by adding the
NDA_IFINDEX attribute to the dump request.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-07 04:12:02 -07:00
David Ahern
21fdd092ac net: Add support for filtering neigh dump by master device
Add support for filtering neighbor dumps by master device by adding
the NDA_MASTER attribute to the dump request. A new netlink flag,
NLM_F_DUMP_FILTERED, is added to indicate the kernel supports the
request and output is filtered as requested.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29 21:33:54 -07:00
Rick Jones
fb811395cd net: add explicit logging and stat for neighbour table overflow
Add an explicit neighbour table overflow message (ratelimited) and
statistic to make diagnosing neighbour table overflows tractable in
the wild.

Diagnosing a neighbour table overflow can be quite difficult in the wild
because there is no explicit dmesg logged.  Callers to neighbour code
seem to use net_dbg_ratelimit when the neighbour call fails which means
the "base message" is not emitted and the callback suppressed messages
from the ratelimiting can end-up juxtaposed with unrelated messages.
Further, a forced garbage collection will increment a stat on each call
whether it was successful in freeing-up a table entry or not, so that
statistic is only a hint.  So, add a net_info_ratelimited message and
explicit statistic to the neighbour code.

Signed-off-by: Rick Jones <rick.jones2@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-10 13:46:21 -07:00
David S. Miller
3a07bd6fea Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/mellanox/mlx4/main.c
	net/packet/af_packet.c

Both conflicts were cases of simple overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-24 02:58:51 -07:00
Julian Anastasov
2c51a97f76 neigh: do not modify unlinked entries
The lockless lookups can return entry that is unlinked.
Sometimes they get reference before last neigh_cleanup_and_release,
sometimes they do not need reference. Later, any
modification attempts may result in the following problems:

1. entry is not destroyed immediately because neigh_update
can start the timer for dead entry, eg. on change to NUD_REACHABLE
state. As result, entry lives for some time but is invisible
and out of control.

2. __neigh_event_send can run in parallel with neigh_destroy
while refcnt=0 but if timer is started and expired refcnt can
reach 0 for second time leading to second neigh_destroy and
possible crash.

Thanks to Eric Dumazet and Ying Xue for their work and analyze
on the __neigh_event_send change.

Fixes: 767e97e1e0db ("neigh: RCU conversion of struct neighbour")
Fixes: a263b3093641 ("ipv4: Make neigh lookups directly in output packet path.")
Fixes: 6fd6ce2056de ("ipv6: Do not depend on rt->n in ip6_finish_output2().")
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-21 09:43:40 -07:00
Erik Kline
765c9c639f neigh: Better handling of transition to NUD_PROBE state
[1] When entering NUD_PROBE state via neigh_update(), perhaps received
    from userspace, correctly (re)initialize the probes count to zero.

    This is useful for forcing revalidation of a neighbor (for example
    if the host is attempting to do DNA [IPv4 4436, IPv6 6059]).

[2] Notify listeners when a neighbor goes into NUD_PROBE state.

    By sending notifications on entry to NUD_PROBE state listeners get
    more timely warnings of imminent connectivity issues.

    The current notifications on entry to NUD_STALE have somewhat
    limited usefulness: NUD_STALE is a perfectly normal state, as is
    NUD_DELAY, whereas notifications on entry to NUD_FAILURE come after
    a neighbor reachability problem has been confirmed (typically after
    three probes).

Signed-off-by: Erik Kline <ek@google.com>
Acked-By: Lorenzo Colitti <lorenzo@google.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-21 16:52:17 -04:00
YOSHIFUJI Hideaki/吉藤英明
8da86466b8 net: neighbour: Add mcast_resolicit to configure the number of multicast resolicitations in PROBE state.
We send unicast neighbor (ARP or NDP) solicitations ucast_probes
times in PROBE state.  Zhu Yanjun reported that some implementation
does not reply against them and the entry will become FAILED, which
is undesirable.

We had been dealt with such nodes by sending multicast probes mcast_
solicit times after unicast probes in PROBE state.  In 2003, I made
a change not to send them to improve compatibility with IPv6 NDP.

Let's introduce per-protocol per-interface sysctl knob "mcast_
reprobe" to configure the number of multicast (re)solicitation for
reconfirmation in PROBE state.  The default is 0, since we have
been doing so for 10+ years.

Reported-by: Zhu Yanjun <Yanjun.Zhu@windriver.com>
CC: Ulf Samuelsson <ulf.samuelsson@ericsson.com>
Signed-off-by: YOSHIFUJI Hideaki <hideaki.yoshifuji@miraclelinux.com>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-20 21:47:40 -04:00
Eric W. Biederman
efd7ef1c19 net: Kill hold_net release_net
hold_net and release_net were an idea that turned out to be useless.
The code has been disabled since 2008.  Kill the code it is long past due.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-12 14:39:40 -04:00
Eric W. Biederman
b79bda3d38 neigh: Use neigh table index for neigh_packet_xmit
Remove a little bit of unnecessary work when transmitting a packet with
neigh_packet_xmit.  Use the neighbour table index not the address family
as a parameter.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-08 19:30:06 -04:00
Eric W. Biederman
4fd3d7d9e8 neigh: Add helper function neigh_xmit
For MPLS I am building the code so that either the neighbour mac
address can be specified or we can have a next hop in ipv4 or ipv6.

The kind of next hop we have is indicated by the neighbour table
pointer.  A neighbour table pointer of NULL is a link layer address.
A non-NULL neighbour table pointer indicates which neighbour table and
thus which address family the next hop address is in that we need to
look up.

The code either sends a packet directly or looks up the appropriate
neighbour table entry and sends the packet.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 00:23:23 -05:00
Eric W. Biederman
60395a20ff neigh: Factor out ___neigh_lookup_noref
While looking at the mpls code I found myself writing yet another
version of neigh_lookup_noref.  We currently have __ipv4_lookup_noref
and __ipv6_lookup_noref.

So to make my work a little easier and to make it a smidge easier to
verify/maintain the mpls code in the future I stopped and wrote
___neigh_lookup_noref.  Then I rewote __ipv4_lookup_noref and
__ipv6_lookup_noref in terms of this new function.  I tested my new
version by verifying that the same code is generated in
ip_finish_output2 and ip6_finish_output2 where these functions are
inlined.

To get to ___neigh_lookup_noref I added a new neighbour cache table
function key_eq.  So that the static size of the key would be
available.

I also added __neigh_lookup_noref for people who want to to lookup
a neighbour table entry quickly but don't know which neibhgour table
they are going to look up.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 00:23:23 -05:00
Eric W. Biederman
435e8eb27e neigh: Don't require a dst in neigh_resolve_output
Having a dst helps a little bit for teql but is fundamentally
unnecessary and there are code paths where a dst is not available that
it would be nice to use the neighbour cache.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-02 16:43:41 -05:00
Eric W. Biederman
bdf53c5849 neigh: Don't require dst in neigh_hh_init
- Add protocol to neigh_tbl so that dst->ops->protocol is not needed
- Acquire the device from neigh->dev

This results in a neigh_hh_init that will cache the samve values
regardless of the packets flowing through it.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-02 16:43:41 -05:00
Eric W. Biederman
def6775369 neigh: Move neigh_compat_output into ax25_ip.c
The only caller is now is ax25_neigh_construct so move
neigh_compat_output into ax25_ip.c make it static and rename it
ax25_neigh_output.

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-hams@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-02 16:43:40 -05:00
David S. Miller
7b46a644a4 netlink: Fix bugs in nlmsg_end() conversions.
Commit 053c095a82cf ("netlink: make nlmsg_end() and genlmsg_end()
void") didn't catch all of the cases where callers were breaking out
on the return value being equal to zero, which they no longer should
when zero means success.

Fix all such cases.

Reported-by: Marcel Holtmann <marcel@holtmann.org>
Reported-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-18 23:36:08 -05:00
Johannes Berg
053c095a82 netlink: make nlmsg_end() and genlmsg_end() void
Contrary to common expectations for an "int" return, these functions
return only a positive value -- if used correctly they cannot even
return 0 because the message header will necessarily be in the skb.

This makes the very common pattern of

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

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

  return nlmsg_end(...);

and the caller is expected to deal with it.

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

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

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

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

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

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

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

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

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-18 01:03:45 -05:00
Jean-Francois Remy
4bf6980dd0 neighbour: fix base_reachable_time(_ms) not effective immediatly when changed
When setting base_reachable_time or base_reachable_time_ms on a
specific interface through sysctl or netlink, the reachable_time
value is not updated.

This means that neighbour entries will continue to be updated using the
old value until it is recomputed in neigh_period_work (which
    recomputes the value every 300*HZ).
On systems with HZ equal to 1000 for instance, it means 5mins before
the change is effective.

This patch changes this behavior by recomputing reachable_time after
each set on base_reachable_time or base_reachable_time_ms.
The new value will become effective the next time the neighbour's timer
is triggered.

Changes are made in two places: the netlink code for set and the sysctl
handling code. For sysctl, I use a proc_handler. The ipv6 network
code does provide its own handler but it already refreshes
reachable_time correctly so it's not an issue.
Any other user of neighbour which provide its own handlers must
refresh reachable_time.

Signed-off-by: Jean-Francois Remy <jeff@melix.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-14 00:28:00 -05:00
WANG Cong
d7480fd3b1 neigh: remove dynamic neigh table registration support
Currently there are only three neigh tables in the whole kernel:
arp table, ndisc table and decnet neigh table. What's more,
we don't support registering multiple tables per family.
Therefore we can just make these tables statically built-in.

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-11 15:23:54 -05:00
Nicolas Dichtel
75fbfd3323 neigh: optimize neigh_parms_release()
In neigh_parms_release() we loop over all entries to find the entry given in
argument and being able to remove it from the list. By using a double linked
list, we can avoid this loop.

Here are some numbers with 30 000 dummy interfaces configured:

Before the patch:
$ time rmmod dummy
real	2m0.118s
user	0m0.000s
sys	1m50.048s

After the patch:
$ time rmmod dummy
real	1m9.970s
user	0m0.000s
sys	0m47.976s

Suggested-by: Thierry Herbelot <thierry.herbelot@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-29 16:11:50 -04:00
Jun Zhao
545469f7a5 neighbour : fix ndm_type type error issue
ndm_type means L3 address type, in neighbour proxy and vxlan, it's RTN_UNICAST.
NDA_DST is for netlink TLV type, hence it's not right value in this context.

Signed-off-by: Jun Zhao <mypopydev@gmail.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-28 17:52:17 -07:00
Mathias Krause
9ecf07a1d8 neigh: sysctl - simplify address calculation of gc_* variables
The code in neigh_sysctl_register() relies on a specific layout of
struct neigh_table, namely that the 'gc_*' variables are directly
following the 'parms' member in a specific order. The code, though,
expresses this in the most ugly way.

Get rid of the ugly casts and use the 'tbl' pointer to get a handle to
the table. This way we can refer to the 'gc_*' variables directly.

Similarly seen in the grsecurity patch, written by Brad Spengler.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Brad Spengler <spender@grsecurity.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-14 14:32:51 -07:00
Duan Jiong
2176d5d418 neigh: set nud_state to NUD_INCOMPLETE when probing router reachability
Since commit 7e98056964("ipv6: router reachability probing"), a router falls
into NUD_FAILED will be probed.

Now if function rt6_select() selects a router which neighbour state is NUD_FAILED,
and at the same time function rt6_probe() changes the neighbour state to NUD_PROBE,
then function dst_neigh_output() can directly send packets, but actually the
neighbour still is unreachable. If we set nud_state to NUD_INCOMPLETE instead
NUD_PROBE, packets will not be sent out until the neihbour is reachable.

In addition, because the route should be probes with a single NS, so we must
set neigh->probes to neigh_max_probes(), then the neigh timer timeout and function
neigh_timer_handler() will not send other NS Messages.

Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 12:43:05 -04:00
David S. Miller
67ddc87f16 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/wireless/ath/ath9k/recv.c
	drivers/net/wireless/mwifiex/pcie.c
	net/ipv6/sit.c

The SIT driver conflict consists of a bug fix being done by hand
in 'net' (missing u64_stats_init()) whilst in 'net-next' a helper
was created (netdev_alloc_pcpu_stats()) which takes care of this.

The two wireless conflicts were overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-05 20:32:02 -05:00
Duan Jiong
feff9ab2e7 neigh: recompute reachabletime before returning from neigh_periodic_work()
If the neigh table's entries is less than gc_thresh1, the function
will return directly, and the reachabletime will not be recompute,
so the reachabletime can be guessed.

Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-27 18:21:17 -05:00