linux/net
Ido Schimmel 563f23b002 nexthop: Fix division by zero while replacing a resilient group
The resilient nexthop group torture tests in fib_nexthop.sh exposed a
possible division by zero while replacing a resilient group [1]. The
division by zero occurs when the data path sees a resilient nexthop
group with zero buckets.

The tests replace a resilient nexthop group in a loop while traffic is
forwarded through it. The tests do not specify the number of buckets
while performing the replacement, resulting in the kernel allocating a
stub resilient table (i.e, 'struct nh_res_table') with zero buckets.

This table should never be visible to the data path, but the old nexthop
group (i.e., 'oldg') might still be used by the data path when the stub
table is assigned to it.

Fix this by only assigning the stub table to the old nexthop group after
making sure the group is no longer used by the data path.

Tested with fib_nexthops.sh:

Tests passed: 222
Tests failed:   0

[1]
 divide error: 0000 [#1] PREEMPT SMP KASAN
 CPU: 0 PID: 1850 Comm: ping Not tainted 5.14.0-custom-10271-ga86eb53057fe #1107
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 04/01/2014
 RIP: 0010:nexthop_select_path+0x2d2/0x1a80
[...]
 Call Trace:
  fib_select_multipath+0x79b/0x1530
  fib_select_path+0x8fb/0x1c10
  ip_route_output_key_hash_rcu+0x1198/0x2da0
  ip_route_output_key_hash+0x190/0x340
  ip_route_output_flow+0x21/0x120
  raw_sendmsg+0x91d/0x2e10
  inet_sendmsg+0x9e/0xe0
  __sys_sendto+0x23d/0x360
  __x64_sys_sendto+0xe1/0x1b0
  do_syscall_64+0x35/0x80
  entry_SYSCALL_64_after_hwframe+0x44/0xae

Cc: stable@vger.kernel.org
Fixes: 283a72a559 ("nexthop: Add implementation of resilient next-hop groups")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-20 09:45:14 +01:00
..
6lowpan 6lowpan: iphc: Fix an off-by-one check of array index 2021-07-22 16:19:03 +02:00
9p net/9p: increase default msize to 128k 2021-09-05 08:36:44 +09:00
802 net: 802: remove dead leftover after ipx driver removal 2021-08-13 16:30:35 -07:00
8021q dev_ioctl: split out ndo_eth_ioctl 2021-07-27 20:11:45 +01:00
appletalk net: socket: rework compat_ifreq_ioctl() 2021-07-23 14:20:25 +01:00
atm
ax25 ax25: use skb_expand_head 2021-08-03 11:21:39 +01:00
batman-adv Kbuild updates for v5.15 2021-09-03 15:33:47 -07:00
bluetooth TTY / Serial patches for 5.15-rc1 2021-09-01 09:51:16 -07:00
bpf bpf: Refactor BPF_PROG_RUN into a function 2021-08-17 00:45:07 +02:00
bpfilter bpfilter: Specify the log level for the kmsg message 2021-06-25 13:13:50 +02:00
bridge net: bridge: mcast: fix vlan port router deadlock 2021-09-03 13:43:19 +01:00
caif net-caif: avoid user-triggerable WARN_ON(1) 2021-09-14 12:51:15 +01:00
can net: Remove redundant if statements 2021-08-05 13:27:50 +01:00
ceph Networking changes for 5.14. 2021-06-30 15:51:09 -07:00
core napi: fix race inside napi_enable 2021-09-20 09:41:29 +01:00
dcb
dccp dccp: don't duplicate ccid when cloning dccp sock 2021-09-08 11:28:35 +01:00
decnet net: Remove redundant if statements 2021-08-05 13:27:50 +01:00
dns_resolver
dsa net: dsa: tear down devlink port regions when tearing down the devlink port on error 2021-09-19 13:05:44 +01:00
ethernet move netdev_boot_setup into Space.c 2021-08-03 13:05:26 +01:00
ethtool ethtool: extend coalesce setting uAPI with CQE mode 2021-08-24 07:38:29 -07:00
hsr
ieee802154 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-08-13 06:41:22 -07:00
ife
ipv4 nexthop: Fix division by zero while replacing a resilient group 2021-09-20 09:45:14 +01:00
ipv6 ipv6: delay fib6_sernum increase in fib6_add 2021-09-13 13:00:53 +01:00
iucv net/iucv: Replace deprecated CPU-hotplug functions. 2021-08-09 10:13:32 +01:00
kcm net: sock: introduce sk_error_report 2021-06-29 11:28:21 -07:00
key
l2tp net/l2tp: Fix reference count leak in l2tp_udp_recv_core 2021-09-09 11:00:20 +01:00
l3mdev
lapb
llc net: Remove redundant if statements 2021-08-05 13:27:50 +01:00
mac80211 mac80211: parse transmit power envelope element 2021-08-26 10:18:56 +02:00
mac802154 ieee802154: Remove redundant initialization of variable ret 2021-09-07 14:06:08 +01:00
mctp mctp: perform route destruction under RCU read lock 2021-09-08 11:29:16 +01:00
mpls mpls: defer ttl decrement in mpls_forward() 2021-07-23 17:17:56 +01:00
mptcp mptcp: Only send extra TCP acks in eligible socket states 2021-09-03 11:49:30 +01:00
ncsi net/ncsi: add get MAC address command to get Intel i210 MAC address 2021-09-01 17:18:56 -07:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2021-09-03 16:20:37 -07:00
netlabel net: fix NULL pointer reference in cipso_v4_doi_free 2021-08-30 12:23:18 +01:00
netlink net: netlink: Remove unused function 2021-07-30 18:35:47 +02:00
netrom net: Remove redundant if statements 2021-08-05 13:27:50 +01:00
nfc net: in_irq() cleanup 2021-08-13 14:09:19 -07:00
nsh
openvswitch Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-08-19 18:09:18 -07:00
packet net/packet: clarify source of pr_*() messages 2021-09-10 10:00:59 +01:00
phonet net: Remove redundant if statements 2021-08-05 13:27:50 +01:00
psample
qrtr net: qrtr: revert check in qrtr_endpoint_post() 2021-09-02 11:37:02 +01:00
rds net/rds: dma_map_sg is entitled to merge entries 2021-08-18 15:35:50 -07:00
rfkill
rose
rxrpc net: RxRPC: make dependent Kconfig symbols be shown indented 2021-08-18 10:12:11 +01:00
sched fq_codel: reject silly quantum parameters 2021-09-04 10:49:46 +01:00
sctp sctp: move the active_key update after sh_keys is added 2021-08-03 11:43:43 +01:00
smc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-08-13 06:41:22 -07:00
strparser net: sock: introduce sk_error_report 2021-06-29 11:28:21 -07:00
sunrpc Critical bug fixes: 2021-09-08 15:55:42 -07:00
switchdev net: make switchdev_bridge_port_{,unoffload} loosely coupled with the bridge 2021-08-04 12:35:07 +01:00
tipc tipc: increase timeout in tipc_sk_enqueue() 2021-09-13 12:43:10 +01:00
tls Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-06-29 15:45:27 -07:00
unix net/af_unix: fix a data-race in unix_dgram_poll 2021-09-09 10:57:52 +01:00
vmw_vsock af_vsock: rename variables in receive loop 2021-09-06 02:25:16 -04:00
wireless cfg80211: use wiphy DFS domain if it is self-managed 2021-08-26 11:04:55 +02:00
x25
xdp Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-06-29 15:45:27 -07:00
xfrm Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ 2021-08-27 11:16:29 +01:00
compat.c
devres.c
Kconfig mctp: Add MCTP base 2021-07-29 15:06:49 +01:00
Makefile mctp: Add MCTP base 2021-07-29 15:06:49 +01:00
socket.c Core: 2021-08-31 16:43:06 -07:00
sysctl_net.c