linux/net/ipv6
Andrea Mayer ae68d93354 seg6: fix the iif in the IPv6 socket control block
When an IPv4 packet is received, the ip_rcv_core(...) sets the receiving
interface index into the IPv4 socket control block (v5.16-rc4,
net/ipv4/ip_input.c line 510):

    IPCB(skb)->iif = skb->skb_iif;

If that IPv4 packet is meant to be encapsulated in an outer IPv6+SRH
header, the seg6_do_srh_encap(...) performs the required encapsulation.
In this case, the seg6_do_srh_encap function clears the IPv6 socket control
block (v5.16-rc4 net/ipv6/seg6_iptunnel.c line 163):

    memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));

The memset(...) was introduced in commit ef489749aa ("ipv6: sr: clear
IP6CB(skb) on SRH ip4ip6 encapsulation") a long time ago (2019-01-29).

Since the IPv6 socket control block and the IPv4 socket control block share
the same memory area (skb->cb), the receiving interface index info is lost
(IP6CB(skb)->iif is set to zero).

As a side effect, that condition triggers a NULL pointer dereference if
commit 0857d6f8c7 ("ipv6: When forwarding count rx stats on the orig
netdev") is applied.

To fix that issue, we set the IP6CB(skb)->iif with the index of the
receiving interface once again.

Fixes: ef489749aa ("ipv6: sr: clear IP6CB(skb) on SRH ip4ip6 encapsulation")
Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20211208195409.12169-1-andrea.mayer@uniroma2.it
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-09 07:55:42 -08:00
..
ila net: ipv6: check return value of rhashtable_init 2021-09-28 12:59:24 +01:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-10-22 11:41:16 +01:00
addrconf_core.c ipv6: add ipv6_dev_find to stubs 2021-03-30 13:29:39 -07:00
addrconf.c net: ndisc: introduce ndisc_evict_nocarrier sysctl parameter 2021-11-01 19:57:14 -07:00
addrlabel.c ipv6: addrlabel: fix possible memory leak in ip6addrlbl_net_init 2020-11-25 11:20:16 -08:00
af_inet6.c net: ipv6: add fib6_nh_release_dsts stub 2021-11-22 15:44:49 +00:00
ah6.c xfrm: remove hdr_offset indirection 2021-06-11 14:48:50 +02:00
anycast.c ipv6: fix memory leaks on IPV6_ADDRFORM path 2020-07-30 16:30:55 -07:00
calipso.c cipso,calipso: resolve a number of problems with the DOI refcounts 2021-03-04 15:26:57 -08:00
datagram.c lsm,selinux: pass flowi_common instead of flowi to the LSM hooks 2020-11-23 18:36:21 -05:00
esp6_offload.c xfrm: remove description from xfrm_type struct 2021-06-09 09:38:52 +02:00
esp6.c ipv6: check return value of ipv6_skip_exthdr 2021-11-18 11:42:06 +00:00
exthdrs_core.c
exthdrs_offload.c
exthdrs.c ipv6: ioam: Distinguish input and output for hop-limit 2021-10-04 12:53:35 +01:00
fib6_notifier.c
fib6_rules.c ipv6: fix memory leak in fib6_rule_suppress 2021-11-29 14:43:35 +00:00
fou6.c net: Add MODULE_DESCRIPTION entries to network modules 2020-06-20 21:33:57 -07:00
icmp.c ipv6: ICMPV6: add response to ICMPV6 RFC 8335 PROBE messages 2021-06-28 14:29:45 -07:00
inet6_connection_sock.c lsm,selinux: pass flowi_common instead of flowi to the LSM hooks 2020-11-23 18:36:21 -05:00
inet6_hashtables.c net: prefer socket bound to interface when not in VRF 2021-10-07 07:27:55 -07:00
ioam6_iptunnel.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-10-14 16:50:14 -07:00
ioam6.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-10-14 16:50:14 -07:00
ip6_checksum.c
ip6_fib.c ipv6: delay fib6_sernum increase in fib6_add 2021-09-13 13:00:53 +01:00
ip6_flowlabel.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-08-05 20:13:21 -07:00
ip6_gre.c ip: use dev_addr_set() in tunnels 2021-10-13 09:41:37 -07:00
ip6_icmp.c net: icmp: pass zeroed opts from icmp{,v6}_ndo_send before sending 2021-02-23 11:29:52 -08:00
ip6_input.c ipv6: weaken the v4mapped source check 2021-03-18 11:19:23 -07:00
ip6_offload.c gro: Fix inconsistent indenting 2021-12-02 12:21:11 +00:00
ip6_offload.h
ip6_output.c ipv6: fix typos in __ip6_finish_output() 2021-11-22 12:42:07 +00:00
ip6_tunnel.c ip: use dev_addr_set() in tunnels 2021-10-13 09:41:37 -07:00
ip6_udp_tunnel.c net: Make locking in sock_bindtoindex optional 2020-06-01 14:57:14 -07:00
ip6_vti.c ip: use dev_addr_set() in tunnels 2021-10-13 09:41:37 -07:00
ip6mr.c net: Remove redundant if statements 2021-08-05 13:27:50 +01:00
ipcomp6.c xfrm: remove hdr_offset indirection 2021-06-11 14:48:50 +02:00
ipv6_sockglue.c ipv6: guard IPV6_MINHOPCOUNT with a static key 2021-10-25 18:02:13 -07:00
Kconfig ipv6: ioam: Add support for the ip6ip6 encapsulation 2021-10-04 12:53:35 +01:00
Makefile net: ipv6: use ipv6-y directly instead of ipv6-objs 2021-09-28 13:13:40 +01:00
mcast_snoop.c net: bridge: mcast: fix broken length + header check for MRDv6 Adv. 2021-04-27 14:02:06 -07:00
mcast.c ipv6: change return type from int to void for mld_process_v2 2021-09-02 11:29:55 +01:00
mip6.c xfrm: ipv6: move mip6_rthdr_offset into xfrm core 2021-06-11 14:48:50 +02:00
ndisc.c net: ndisc: introduce ndisc_evict_nocarrier sysctl parameter 2021-11-01 19:57:14 -07:00
netfilter.c netfilter: Dissect flow after packet mangling 2021-04-18 22:04:16 +02:00
output_core.c ipv6: use prandom_u32() for ID generation 2021-05-31 22:12:08 -07:00
ping.c lsm,selinux: pass flowi_common instead of flowi to the LSM hooks 2020-11-23 18:36:21 -05:00
proc.c net: udp: introduce UDP_MIB_MEMERRORS for udp_mem 2020-11-09 15:34:44 -08:00
protocol.c
raw.c net: sock: introduce sk_error_report 2021-06-29 11:28:21 -07:00
reassembly.c ipv6: record frag_max_size in atomic fragments in input path 2021-05-21 15:02:25 -07:00
route.c net: ipv6: add fib6_nh_release_dsts stub 2021-11-22 15:44:49 +00:00
rpl_iptunnel.c net: ipv6: rpl_iptunnel: simplify the return expression of rpl_do_srh() 2020-12-08 16:22:54 -08:00
rpl.c net: ipv6: rpl*: Fix strange kerneldoc warnings due to bad header 2020-10-30 12:12:52 -07:00
seg6_hmac.c net: ipv6: check return value of rhashtable_init 2021-09-28 12:59:24 +01:00
seg6_iptunnel.c seg6: fix the iif in the IPv6 socket control block 2021-12-09 07:55:42 -08:00
seg6_local.c ipv6: seg6: remove duplicated include 2021-08-31 12:41:47 +01:00
seg6.c net:ipv6:Remove unneeded semicolon 2021-11-03 11:18:46 +00:00
sit.c ip: use dev_addr_set() in tunnels 2021-10-13 09:41:37 -07:00
syncookies.c selinux/stable-5.11 PR 20201214 2020-12-16 11:01:04 -08:00
sysctl_net_ipv6.c ipv6: ioam: Data plane support for Pre-allocated Trace 2021-07-21 08:14:33 -07:00
tcp_ipv6.c ipv6: remove useless assignment to newinet in tcp_v6_syn_recv_sock() 2021-11-05 19:49:40 -07:00
tcpv6_offload.c
tunnel6.c tunnel6: add tunnel6_input_afinfo for ipip and ipv6 tunnels 2020-07-09 12:52:37 +02:00
udp_impl.h net: pass a sockptr_t into ->setsockopt 2020-07-24 15:41:54 -07:00
udp_offload.c udp: properly complete L4 GRO over UDP tunnel packet 2021-03-30 17:06:49 -07:00
udp.c net: udp6: replace __UDP_INC_STATS() with __UDP6_INC_STATS() 2021-11-03 14:00:23 +00:00
udplite.c net/ipv6: remove compat_ipv6_{get,set}sockopt 2020-07-19 18:16:41 -07:00
xfrm6_input.c xfrm: state: remove extract_input indirection from xfrm_state_afinfo 2020-05-06 09:40:08 +02:00
xfrm6_output.c net: ipv6: fix return value of ip6_skb_dst_mtu 2021-07-02 11:57:01 -07:00
xfrm6_policy.c
xfrm6_protocol.c xfrm: add support for UDPv6 encapsulation of ESP 2020-04-28 11:28:36 +02:00
xfrm6_state.c xfrm: remove output_finish indirection from xfrm_state_afinfo 2020-05-06 09:40:08 +02:00
xfrm6_tunnel.c xfrm: remove description from xfrm_type struct 2021-06-09 09:38:52 +02:00