linux/net/ipv4
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
..
bpfilter net: Revert "net: optimize the sockptr_t for unified kernel/user address spaces" 2020-08-10 12:06:44 -07:00
netfilter netfilter: x_tables: handle xt_register_template() returning an error value 2021-08-25 13:06:48 +02:00
af_inet.c bpf: Migrate cgroup_bpf to internal cgroup_bpf_attach_type enum 2021-08-23 17:50:24 -07:00
ah4.c Networking changes for 5.14. 2021-06-30 15:51:09 -07:00
arp.c net: Exempt multicast addresses from five-second neighbor lifetime 2020-11-13 14:24:39 -08:00
bpf_tcp_ca.c bpf: tcp: Allow bpf-tcp-cc to call bpf_(get|set)sockopt 2021-08-25 17:40:35 -07:00
cipso_ipv4.c net: remove the unnecessary check in cipso_v4_doi_free 2021-09-03 13:52:29 +01:00
datagram.c
devinet.c net: add extack arg for link ops 2021-08-04 10:01:26 +01:00
esp4_offload.c xfrm: remove description from xfrm_type struct 2021-06-09 09:38:52 +02:00
esp4.c ipsec: Remove unneeded extra variable in esp4 esp_ssg_unref() 2021-07-20 16:14:23 +02:00
fib_frontend.c net: Use nlmsg_unicast() instead of netlink_unicast() 2021-07-13 09:28:29 -07:00
fib_lookup.h ipv4: Fix spelling mistakes 2021-06-07 14:08:30 -07:00
fib_notifier.c
fib_rules.c fib: use indirect call wrappers in the most common fib_rules_ops 2020-07-28 17:42:31 -07:00
fib_semantics.c net: Remove redundant if statements 2021-08-05 13:27:50 +01:00
fib_trie.c memcg: enable accounting for IP address and routing-related objects 2021-07-20 06:00:38 -07:00
fou.c fou: remove sparse errors 2021-08-31 12:03:33 +01:00
gre_demux.c net: Remove the member netns_ok 2021-05-17 15:29:35 -07:00
gre_offload.c ip_gre: add csum offload support for gre header 2021-01-29 20:39:14 -08:00
icmp.c net: Remove redundant if statements 2021-08-05 13:27:50 +01:00
igmp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-08-13 06:41:22 -07:00
inet_connection_sock.c net-memcg: pass in gfp_t mask to mem_cgroup_charge_skmem() 2021-08-18 11:39:44 +01:00
inet_diag.c net: Use nlmsg_unicast() instead of netlink_unicast() 2021-07-13 09:28:29 -07:00
inet_fragment.c inet: frags: batch fqdir destroy works 2020-12-12 15:08:54 -08:00
inet_hashtables.c tcp: Keep TCP_CLOSE sockets in the reuseport group. 2021-06-15 18:01:05 +02:00
inet_timewait_sock.c net: Use generic ns_common::count 2020-08-19 14:06:36 +02:00
inetpeer.c inetpeer: use div64_ul() and clamp_val() calculate inet_peer_threshold 2021-03-01 13:32:12 -08:00
ip_forward.c
ip_fragment.c
ip_gre.c ip_gre: validate csum_start only on pull 2021-09-05 18:59:32 +01:00
ip_input.c net: use indirect call helpers for dst_input 2021-02-03 14:51:39 -08:00
ip_options.c net: clean up codestyle for net/ipv4 2020-08-25 06:28:02 -07:00
ip_output.c net: ipv4: Fix the warning for dereference 2021-08-30 12:47:09 +01:00
ip_sockglue.c Revert "Revert "ipv4: fix memory leaks in ip_cmsg_send() callers"" 2021-09-14 14:24:31 +01:00
ip_tunnel_core.c net: ip_tunnel: clean up endianness conversions 2021-01-08 19:25:35 -08:00
ip_tunnel.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-07-31 09:14:46 -07:00
ip_vti.c ip_tunnel: use ndo_siocdevprivate 2021-07-27 20:11:44 +01:00
ipcomp.c Networking changes for 5.14. 2021-06-30 15:51:09 -07:00
ipconfig.c net: ipconfig: Don't override command-line hostnames or domains 2021-06-02 13:27:03 -07:00
ipip.c ip_tunnel: use ndo_siocdevprivate 2021-07-27 20:11:44 +01:00
ipmr_base.c
ipmr.c ipmr: Fix indentation issue 2021-07-07 20:52:25 -07:00
Kconfig net: ipv4: remove duplicate "the the" phrase in Kconfig text 2020-08-18 16:02:16 -07:00
Makefile bpf: Clean up sockmap related Kconfigs 2021-02-26 12:28:03 -08:00
metrics.c treewide: rename nla_strlcpy to nla_strscpy. 2020-11-16 08:08:54 -08:00
netfilter.c netfilter: Dissect flow after packet mangling 2021-04-18 22:04:16 +02:00
netlink.c
nexthop.c nexthop: Fix division by zero while replacing a resilient group 2021-09-20 09:45:14 +01:00
ping.c Revert "Revert "ipv4: fix memory leaks in ip_cmsg_send() callers"" 2021-09-14 14:24:31 +01:00
proc.c tcp: Add stats for socket migration. 2021-06-23 12:56:08 -07:00
protocol.c net: Remove the member netns_ok 2021-05-17 15:29:35 -07:00
raw_diag.c net: Use nlmsg_unicast() instead of netlink_unicast() 2021-07-13 09:28:29 -07:00
raw.c Revert "Revert "ipv4: fix memory leaks in ip_cmsg_send() callers"" 2021-09-14 14:24:31 +01:00
route.c ipv4: fix endianness issue in inet_rtm_getroute_build_skb() 2021-08-31 12:03:03 +01:00
syncookies.c selinux/stable-5.11 PR 20201214 2020-12-16 11:01:04 -08:00
sysctl_net_ipv4.c net: Introduce net.ipv4.tcp_migrate_req. 2021-06-15 18:01:05 +02:00
tcp_bbr.c tcp_bbr: fix u32 wrap bug in round logic if bbr_init() called after 2B packets 2021-08-11 15:00:15 -07:00
tcp_bic.c
tcp_bpf.c bpf, sockmap, tcp: sk_prot needs inuse_idx set for proc stats 2021-07-15 19:54:22 +02:00
tcp_cdg.c
tcp_cong.c net: Only allow init netns to set default tcp cong to a restricted algo 2021-05-04 11:58:28 -07:00
tcp_cubic.c tcp: Rename bictcp function prefix to cubictcp 2021-03-26 20:41:51 -07:00
tcp_dctcp.c
tcp_dctcp.h
tcp_diag.c
tcp_fastopen.c tcp: enable data-less, empty-cookie SYN with TFO_SERVER_COOKIE_NOT_REQD 2021-08-16 17:25:49 -07:00
tcp_highspeed.c Replace HTTP links with HTTPS ones: IPv* 2020-07-06 13:23:03 -07:00
tcp_htcp.c Replace HTTP links with HTTPS ones: IPv* 2020-07-06 13:23:03 -07:00
tcp_hybla.c
tcp_illinois.c
tcp_input.c tcp: fix tp->undo_retrans accounting in tcp_sacktag_one() 2021-09-14 14:23:09 +01:00
tcp_ipv4.c Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-07-31 11:23:26 -07:00
tcp_lp.c ipv4: tcp_lp.c: Couple of typo fixes 2021-03-28 17:31:13 -07:00
tcp_metrics.c fixes-v5.11 2020-12-14 16:40:27 -08:00
tcp_minisocks.c tcp: Add stats for socket migration. 2021-06-23 12:56:08 -07:00
tcp_nv.c
tcp_offload.c net, gro: Set inner transport header offset in tcp/udp GRO hook 2021-08-02 10:20:56 +01:00
tcp_output.c net-memcg: pass in gfp_t mask to mem_cgroup_charge_skmem() 2021-08-18 11:39:44 +01:00
tcp_rate.c
tcp_recovery.c tcp: more accurately check DSACKs to grow RACK reordering window 2021-07-27 20:07:21 +01:00
tcp_scalable.c net: ipv4: delete repeated words 2020-08-24 17:31:20 -07:00
tcp_timer.c net: sock: introduce sk_error_report 2021-06-29 11:28:21 -07:00
tcp_ulp.c
tcp_vegas.c tcp: use semicolons rather than commas to separate statements 2020-10-13 17:11:52 -07:00
tcp_vegas.h
tcp_veno.c Replace HTTP links with HTTPS ones: IPv* 2020-07-06 13:23:03 -07:00
tcp_westwood.c
tcp_yeah.c tcp_yeah: check struct yeah size at compile time 2021-06-29 11:54:36 -07:00
tcp.c tcp: enable mid stream window clamp 2021-08-26 18:00:40 -07:00
tunnel4.c net: Remove the member netns_ok 2021-05-17 15:29:35 -07:00
udp_bpf.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-07-23 16:13:06 +01:00
udp_diag.c net: Use nlmsg_unicast() instead of netlink_unicast() 2021-07-13 09:28:29 -07:00
udp_impl.h net: pass a sockptr_t into ->setsockopt 2020-07-24 15:41:54 -07:00
udp_offload.c fou: remove sparse errors 2021-08-31 12:03:33 +01:00
udp_tunnel_core.c udp_tunnel: reshuffle NETIF_F_RX_UDP_TUNNEL_PORT checks 2021-01-07 12:53:29 -08:00
udp_tunnel_nic.c udp_tunnel: Fix udp_tunnel_nic work-queue type 2021-09-13 12:38:45 +01:00
udp_tunnel_stub.c udp_tunnel: add central NIC RX port offload infrastructure 2020-07-10 13:54:00 -07:00
udp.c Revert "Revert "ipv4: fix memory leaks in ip_cmsg_send() callers"" 2021-09-14 14:24:31 +01:00
udplite.c net: Remove the member netns_ok 2021-05-17 15:29:35 -07:00
xfrm4_input.c
xfrm4_output.c
xfrm4_policy.c
xfrm4_protocol.c net: Remove the member netns_ok 2021-05-17 15:29:35 -07:00
xfrm4_state.c
xfrm4_tunnel.c xfrm: remove description from xfrm_type struct 2021-06-09 09:38:52 +02:00