linux/include/net
Benjamin Poirier 0756384fb1 vxlan: Fix nexthop hash size
The nexthop code expects a 31 bit hash, such as what is returned by
fib_multipath_hash() and rt6_multipath_hash(). Passing the 32 bit hash
returned by skb_get_hash() can lead to problems related to the fact that
'int hash' is a negative number when the MSB is set.

In the case of hash threshold nexthop groups, nexthop_select_path_hthr()
will disproportionately select the first nexthop group entry. In the case
of resilient nexthop groups, nexthop_select_path_res() may do an out of
bounds access in nh_buckets[], for example:
    hash = -912054133
    num_nh_buckets = 2
    bucket_index = 65535

which leads to the following panic:

BUG: unable to handle page fault for address: ffffc900025910c8
PGD 100000067 P4D 100000067 PUD 10026b067 PMD 0
Oops: 0002 [#1] PREEMPT SMP KASAN NOPTI
CPU: 4 PID: 856 Comm: kworker/4:3 Not tainted 6.5.0-rc2+ #34
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:nexthop_select_path+0x197/0xbf0
Code: c1 e4 05 be 08 00 00 00 4c 8b 35 a4 14 7e 01 4e 8d 6c 25 00 4a 8d 7c 25 08 48 01 dd e8 c2 25 15 ff 49 8d 7d 08 e8 39 13 15 ff <4d> 89 75 08 48 89 ef e8 7d 12 15 ff 48 8b 5d 00 e8 14 55 2f 00 85
RSP: 0018:ffff88810c36f260 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000000002000c0 RCX: ffffffffaf02dd77
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffc900025910c8
RBP: ffffc900025910c0 R08: 0000000000000001 R09: fffff520004b2219
R10: ffffc900025910cf R11: 31392d2068736168 R12: 00000000002000c0
R13: ffffc900025910c0 R14: 00000000fffef608 R15: ffff88811840e900
FS:  0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc900025910c8 CR3: 0000000129d00000 CR4: 0000000000750ee0
PKRU: 55555554
Call Trace:
 <TASK>
 ? __die+0x23/0x70
 ? page_fault_oops+0x1ee/0x5c0
 ? __pfx_is_prefetch.constprop.0+0x10/0x10
 ? __pfx_page_fault_oops+0x10/0x10
 ? search_bpf_extables+0xfe/0x1c0
 ? fixup_exception+0x3b/0x470
 ? exc_page_fault+0xf6/0x110
 ? asm_exc_page_fault+0x26/0x30
 ? nexthop_select_path+0x197/0xbf0
 ? nexthop_select_path+0x197/0xbf0
 ? lock_is_held_type+0xe7/0x140
 vxlan_xmit+0x5b2/0x2340
 ? __lock_acquire+0x92b/0x3370
 ? __pfx_vxlan_xmit+0x10/0x10
 ? __pfx___lock_acquire+0x10/0x10
 ? __pfx_register_lock_class+0x10/0x10
 ? skb_network_protocol+0xce/0x2d0
 ? dev_hard_start_xmit+0xca/0x350
 ? __pfx_vxlan_xmit+0x10/0x10
 dev_hard_start_xmit+0xca/0x350
 __dev_queue_xmit+0x513/0x1e20
 ? __pfx___dev_queue_xmit+0x10/0x10
 ? __pfx_lock_release+0x10/0x10
 ? mark_held_locks+0x44/0x90
 ? skb_push+0x4c/0x80
 ? eth_header+0x81/0xe0
 ? __pfx_eth_header+0x10/0x10
 ? neigh_resolve_output+0x215/0x310
 ? ip6_finish_output2+0x2ba/0xc90
 ip6_finish_output2+0x2ba/0xc90
 ? lock_release+0x236/0x3e0
 ? ip6_mtu+0xbb/0x240
 ? __pfx_ip6_finish_output2+0x10/0x10
 ? find_held_lock+0x83/0xa0
 ? lock_is_held_type+0xe7/0x140
 ip6_finish_output+0x1ee/0x780
 ip6_output+0x138/0x460
 ? __pfx_ip6_output+0x10/0x10
 ? __pfx___lock_acquire+0x10/0x10
 ? __pfx_ip6_finish_output+0x10/0x10
 NF_HOOK.constprop.0+0xc0/0x420
 ? __pfx_NF_HOOK.constprop.0+0x10/0x10
 ? ndisc_send_skb+0x2c0/0x960
 ? __pfx_lock_release+0x10/0x10
 ? __local_bh_enable_ip+0x93/0x110
 ? lock_is_held_type+0xe7/0x140
 ndisc_send_skb+0x4be/0x960
 ? __pfx_ndisc_send_skb+0x10/0x10
 ? mark_held_locks+0x65/0x90
 ? find_held_lock+0x83/0xa0
 ndisc_send_ns+0xb0/0x110
 ? __pfx_ndisc_send_ns+0x10/0x10
 addrconf_dad_work+0x631/0x8e0
 ? lock_acquire+0x180/0x3f0
 ? __pfx_addrconf_dad_work+0x10/0x10
 ? mark_held_locks+0x24/0x90
 process_one_work+0x582/0x9c0
 ? __pfx_process_one_work+0x10/0x10
 ? __pfx_do_raw_spin_lock+0x10/0x10
 ? mark_held_locks+0x24/0x90
 worker_thread+0x93/0x630
 ? __kthread_parkme+0xdc/0x100
 ? __pfx_worker_thread+0x10/0x10
 kthread+0x1a5/0x1e0
 ? __pfx_kthread+0x10/0x10
 ret_from_fork+0x34/0x60
 ? __pfx_kthread+0x10/0x10
 ret_from_fork_asm+0x1b/0x30
RIP: 0000:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0000:0000000000000000 EFLAGS: 00000000 ORIG_RAX: 0000000000000000
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Modules linked in:
CR2: ffffc900025910c8
---[ end trace 0000000000000000 ]---
RIP: 0010:nexthop_select_path+0x197/0xbf0
Code: c1 e4 05 be 08 00 00 00 4c 8b 35 a4 14 7e 01 4e 8d 6c 25 00 4a 8d 7c 25 08 48 01 dd e8 c2 25 15 ff 49 8d 7d 08 e8 39 13 15 ff <4d> 89 75 08 48 89 ef e8 7d 12 15 ff 48 8b 5d 00 e8 14 55 2f 00 85
RSP: 0018:ffff88810c36f260 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000000002000c0 RCX: ffffffffaf02dd77
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffc900025910c8
RBP: ffffc900025910c0 R08: 0000000000000001 R09: fffff520004b2219
R10: ffffc900025910cf R11: 31392d2068736168 R12: 00000000002000c0
R13: ffffc900025910c0 R14: 00000000fffef608 R15: ffff88811840e900
FS:  0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000129d00000 CR4: 0000000000750ee0
PKRU: 55555554
Kernel panic - not syncing: Fatal exception in interrupt
Kernel Offset: 0x2ca00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

Fix this problem by ensuring the MSB of hash is 0 using a right shift - the
same approach used in fib_multipath_hash() and rt6_multipath_hash().

Fixes: 1274e1cc42 ("vxlan: ecmp support for mac fdb entries")
Signed-off-by: Benjamin Poirier <bpoirier@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-02 10:58:26 +01:00
..
9p
bluetooth Bluetooth: coredump: fix building with coredump disabled 2023-07-20 11:25:24 -07:00
caif
iucv
mana
netfilter
netns
nfc
phonet
sctp
tc_act
6lowpan.h
Space.h
act_api.h
addrconf.h
af_ieee802154.h
af_rxrpc.h
af_unix.h
af_vsock.h
ah.h
amt.h
arp.h
atmclip.h
ax25.h
ax88796.h
bareudp.h
bond_3ad.h
bond_alb.h
bond_options.h
bonding.h net: bonding: remove kernel-doc comment marker 2023-07-14 20:39:29 -07:00
bpf_sk_storage.h
busy_poll.h
calipso.h
cfg80211-wext.h
cfg80211.h
cfg802154.h net: cfg802154: fix kernel-doc notation warnings 2023-07-14 20:39:29 -07:00
checksum.h
cipso_ipv4.h
cls_cgroup.h
codel.h codel: fix kernel-doc notation warnings 2023-07-14 20:39:29 -07:00
codel_impl.h
codel_qdisc.h
compat.h
datalink.h
dcbevent.h
dcbnl.h
devlink.h devlink: fix kernel-doc notation warnings 2023-07-14 20:39:29 -07:00
dropreason-core.h
dropreason.h
dsa.h
dsa_stubs.h
dsfield.h
dst.h
dst_cache.h
dst_metadata.h
dst_ops.h
erspan.h
esp.h
espintcp.h
ethoc.h
failover.h
fib_notifier.h
fib_rules.h
firewire.h
flow.h
flow_dissector.h
flow_offload.h
fou.h
fq.h
fq_impl.h
garp.h
gen_stats.h
genetlink.h
geneve.h
gre.h
gro.h net: gro: fix misuse of CB in udp socket lookup 2023-07-29 17:10:27 +01:00
gro_cells.h
gso.h
gtp.h
gue.h
handshake.h
hwbm.h
icmp.h
ieee80211_radiotap.h
ieee802154_netdev.h
if_inet6.h
ife.h
ila.h
inet6_connection_sock.h
inet6_hashtables.h
inet_common.h
inet_connection_sock.h
inet_dscp.h
inet_ecn.h
inet_frag.h inet: frags: eliminate kernel-doc warning 2023-07-14 20:39:29 -07:00
inet_hashtables.h
inet_sock.h net: annotate data-races around sk->sk_mark 2023-07-29 18:13:41 +01:00
inet_timewait_sock.h
inetpeer.h
ioam6.h
ip.h net: annotate data-races around sk->sk_mark 2023-07-29 18:13:41 +01:00
ip6_checksum.h
ip6_fib.h
ip6_route.h
ip6_tunnel.h
ip_fib.h
ip_tunnels.h
ip_vs.h
ipcomp.h
ipconfig.h
ipv6.h tcp: Reduce chance of collisions in inet6_hashfn(). 2023-07-24 16:52:37 -07:00
ipv6_frag.h
ipv6_stubs.h
iw_handler.h
kcm.h
l3mdev.h
lag.h
lapb.h
lib80211.h
llc.h
llc_c_ac.h
llc_c_ev.h
llc_c_st.h
llc_conn.h llc: Check netns in llc_estab_match() and llc_listener_match(). 2023-07-20 10:46:28 +02:00
llc_if.h
llc_pdu.h net: llc: fix kernel-doc notation warnings 2023-07-14 20:39:29 -07:00
llc_s_ac.h
llc_s_ev.h
llc_s_st.h
llc_sap.h
lwtunnel.h
mac80211.h
mac802154.h
macsec.h
mctp.h
mctpdevice.h
mip6.h
mld.h
mpls.h
mpls_iptunnel.h
mptcp.h
mrp.h
ncsi.h
ndisc.h
neighbour.h
net_debug.h
net_failover.h
net_namespace.h
net_ratelimit.h
net_trackers.h
netdev_queues.h
netevent.h
netlabel.h
netlink.h
netprio_cgroup.h
netrom.h
nexthop.h
nl802154.h
nsh.h net: NSH: fix kernel-doc notation warning 2023-07-14 20:39:29 -07:00
p8022.h
page_pool.h
pie.h pie: fix kernel-doc notation warning 2023-07-14 20:39:30 -07:00
ping.h
pkt_cls.h
pkt_sched.h net/sched: make psched_mtu() RTNL-less safe 2023-07-12 15:59:33 -07:00
pptp.h
protocol.h
psample.h
psnap.h
raw.h
rawv6.h
red.h
regulatory.h
request_sock.h
rose.h
route.h net: annotate data-races around sk->sk_mark 2023-07-29 18:13:41 +01:00
rpl.h
rsi_91x.h rsi: remove kernel-doc comment marker 2023-07-14 20:39:30 -07:00
rtnetlink.h
rtnh.h
sch_generic.h
scm.h
secure_seq.h
seg6.h
seg6_hmac.h
seg6_local.h
selftests.h
slhc_vj.h
smc.h
snmp.h
sock.h
sock_reuseport.h
stp.h
strparser.h
switchdev.h
tc_wrapper.h
tcp.h tcp: annotate data-races around tp->notsent_lowat 2023-07-20 12:34:18 -07:00
tcp_states.h
timewait_sock.h
tipc.h
tls.h
tls_toe.h
transp_v6.h
tso.h
tun_proto.h
udp.h
udp_tunnel.h
udplite.h
vsock_addr.h
vxlan.h vxlan: Fix nexthop hash size 2023-08-02 10:58:26 +01:00
wext.h
x25.h
x25device.h
xdp.h
xdp_priv.h
xdp_sock.h
xdp_sock_drv.h
xfrm.h
xsk_buff_pool.h