mirror_ubuntu-kernels/net/ipv4
Nicolas Dichtel 5b4bd1d800 ip: fix triggering of 'icmp redirect'
BugLink: https://bugs.launchpad.net/bugs/1990124
BugLink: https://bugs.launchpad.net/bugs/1988809

commit eb55dc09b5 upstream.

__mkroute_input() uses fib_validate_source() to trigger an icmp redirect.
My understanding is that fib_validate_source() is used to know if the src
address and the gateway address are on the same link. For that,
fib_validate_source() returns 1 (same link) or 0 (not the same network).
__mkroute_input() is the only user of these positive values, all other
callers only look if the returned value is negative.

Since the below patch, fib_validate_source() didn't return anymore 1 when
both addresses are on the same network, because the route lookup returns
RT_SCOPE_LINK instead of RT_SCOPE_HOST. But this is, in fact, right.
Let's adapat the test to return 1 again when both addresses are on the same
link.

CC: stable@vger.kernel.org
Fixes: 747c143072 ("ip: fix dflt addr selection for connected nexthop")
Reported-by: kernel test robot <yujie.liu@intel.com>
Reported-by: Heng Qi <hengqi@linux.alibaba.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220829100121.3821-1-nicolas.dichtel@6wind.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

(cherry picked from commit 57f1407ca1662288d41c509103f2a1462d1c4dd4 linux-5.15.y)
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
2022-09-20 10:53:40 +02:00
..
bpfilter
netfilter
af_inet.c
ah4.c
arp.c
bpf_tcp_ca.c
cipso_ipv4.c
datagram.c
devinet.c
esp4_offload.c
esp4.c
fib_frontend.c
fib_lookup.h
fib_notifier.c
fib_rules.c
fib_semantics.c
fib_trie.c
fou.c
gre_demux.c
gre_offload.c
icmp.c
igmp.c
inet_connection_sock.c
inet_diag.c
inet_fragment.c
inet_hashtables.c
inet_timewait_sock.c
inetpeer.c
ip_forward.c
ip_fragment.c
ip_gre.c
ip_input.c
ip_options.c
ip_output.c
ip_sockglue.c
ip_tunnel_core.c
ip_tunnel.c
ip_vti.c
ipcomp.c
ipconfig.c
ipip.c
ipmr_base.c
ipmr.c
Kconfig
Makefile
metrics.c
netfilter.c
netlink.c
nexthop.c
ping.c
proc.c
protocol.c
raw_diag.c
raw.c
route.c
syncookies.c
sysctl_net_ipv4.c
tcp_bbr.c
tcp_bic.c
tcp_bpf.c
tcp_cdg.c
tcp_cong.c
tcp_cubic.c
tcp_dctcp.c
tcp_dctcp.h
tcp_diag.c
tcp_fastopen.c
tcp_highspeed.c
tcp_htcp.c
tcp_hybla.c
tcp_illinois.c
tcp_input.c
tcp_ipv4.c
tcp_lp.c
tcp_metrics.c
tcp_minisocks.c
tcp_nv.c
tcp_offload.c
tcp_output.c
tcp_rate.c
tcp_recovery.c
tcp_scalable.c
tcp_timer.c
tcp_ulp.c
tcp_vegas.c
tcp_vegas.h
tcp_veno.c
tcp_westwood.c
tcp_yeah.c
tcp.c
tunnel4.c
udp_bpf.c
udp_diag.c
udp_impl.h
udp_offload.c
udp_tunnel_core.c
udp_tunnel_nic.c
udp_tunnel_stub.c
udp.c
udplite.c
xfrm4_input.c
xfrm4_output.c
xfrm4_policy.c
xfrm4_protocol.c
xfrm4_state.c
xfrm4_tunnel.c