linux/net/ipv6
Eric Dumazet 086d49058c ipv6: annotate some data-races around sk->sk_prot
IPv6 has this hack changing sk->sk_prot when an IPv6 socket
is 'converted' to an IPv4 one with IPV6_ADDRFORM option.

This operation is only performed for TCP and UDP, knowing
their 'struct proto' for the two network families are populated
in the same way, and can not disappear while a reader
might use and dereference sk->sk_prot.

If we think about it all reads of sk->sk_prot while
either socket lock or RTNL is not acquired should be using READ_ONCE().

Also note that other layers like MPTCP, XFRM, CHELSIO_TLS also
write over sk->sk_prot.

BUG: KCSAN: data-race in inet6_recvmsg / ipv6_setsockopt

write to 0xffff8881386f7aa8 of 8 bytes by task 26932 on cpu 0:
 do_ipv6_setsockopt net/ipv6/ipv6_sockglue.c:492 [inline]
 ipv6_setsockopt+0x3758/0x3910 net/ipv6/ipv6_sockglue.c:1019
 udpv6_setsockopt+0x85/0x90 net/ipv6/udp.c:1649
 sock_common_setsockopt+0x5d/0x70 net/core/sock.c:3489
 __sys_setsockopt+0x209/0x2a0 net/socket.c:2180
 __do_sys_setsockopt net/socket.c:2191 [inline]
 __se_sys_setsockopt net/socket.c:2188 [inline]
 __x64_sys_setsockopt+0x62/0x70 net/socket.c:2188
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881386f7aa8 of 8 bytes by task 26911 on cpu 1:
 inet6_recvmsg+0x7a/0x210 net/ipv6/af_inet6.c:659
 ____sys_recvmsg+0x16c/0x320
 ___sys_recvmsg net/socket.c:2674 [inline]
 do_recvmmsg+0x3f5/0xae0 net/socket.c:2768
 __sys_recvmmsg net/socket.c:2847 [inline]
 __do_sys_recvmmsg net/socket.c:2870 [inline]
 __se_sys_recvmmsg net/socket.c:2863 [inline]
 __x64_sys_recvmmsg+0xde/0x160 net/socket.c:2863
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xffffffff85e0e980 -> 0xffffffff85e01580

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 26911 Comm: syz-executor.3 Not tainted 5.17.0-rc2-syzkaller-00316-g0457e5153e0e-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-18 11:53:28 +00:00
..
ila net: ipv6: check return value of rhashtable_init 2021-09-28 12:59:24 +01:00
netfilter netfilter: Remove flowtable relics 2022-01-27 00:00:20 +01:00
addrconf_core.c ipv6: add net device refcount tracker to struct inet6_dev 2021-12-06 16:05:11 -08:00
addrconf.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-02-17 11:44:20 -08:00
addrlabel.c ipv6: addrlabel: fix possible memory leak in ip6addrlbl_net_init 2020-11-25 11:20:16 -08:00
af_inet6.c ipv6: annotate some data-races around sk->sk_prot 2022-02-18 11:53:28 +00:00
ah6.c ipv6: ah6: use swap() to make code cleaner 2021-11-18 12:00:15 +00:00
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 net: move gro definitions to include/net/gro.h 2021-11-16 13:16:54 +00:00
esp6.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2022-01-06 11:54:20 +00:00
exthdrs_core.c
exthdrs_offload.c
exthdrs.c ipv6: partially inline ipv6_fixup_options 2022-01-27 19:46:11 -08:00
fib6_notifier.c
fib6_rules.c ipv6: change fib6_rules_net_exit() to batch mode 2022-02-08 20:41:34 -08:00
fou6.c
icmp.c ipv6: do not use per netns icmp sockets 2022-01-25 11:25:21 +00:00
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 tcp: Don't acquire inet_listen_hashbucket::lock with disabled BH. 2022-02-09 21:28:36 -08:00
ioam6_iptunnel.c ipv6: ioam: Insertion frequency in lwtunnel output 2022-02-04 20:24:45 -08:00
ioam6.c ipv6: ioam: Support for Queue depth data field 2022-01-02 12:15:13 +00:00
ip6_checksum.c
ip6_fib.c ipv6: annotate accesses to fn->fn_sernum 2022-01-20 20:18:37 -08:00
ip6_flowlabel.c ipv6: per-netns exclusive flowlabel checks 2022-02-16 20:37:47 -08:00
ip6_gre.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-01-09 17:00:17 -08:00
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: make mc_forwarding atomic 2022-02-05 15:20:34 +00:00
ip6_offload.c ipv6: gro: flush instead of assuming different flows on hop_limit mismatch 2022-01-25 13:05:11 +00:00
ip6_offload.h
ip6_output.c net: ping6: support setting basic SOL_IPV6 options via cmsg 2022-02-17 14:22:09 +00:00
ip6_tunnel.c ip6_tunnel: fix possible NULL deref in ip6_tnl_xmit 2022-02-09 11:56:19 +00:00
ip6_udp_tunnel.c
ip6_vti.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-12-30 12:12:12 -08:00
ip6mr.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-02-10 17:29:56 -08:00
ipcomp6.c xfrm: remove hdr_offset indirection 2021-06-11 14:48:50 +02:00
ipv6_sockglue.c ipv6: annotate some data-races around sk->sk_prot 2022-02-18 11:53:28 +00:00
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: mcast: use rcu-safe version of ipv6_get_lladdr() 2022-02-14 13:30:37 +00:00
mip6.c xfrm: ipv6: move mip6_rthdr_offset into xfrm core 2021-06-11 14:48:50 +02:00
ndisc.c Generate netlink notification when default IPv6 route preference changes 2022-02-14 11:15:37 +00:00
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 net: ping6: support setting basic SOL_IPV6 options via cmsg 2022-02-17 14:22:09 +00:00
proc.c net: udp: introduce UDP_MIB_MEMERRORS for udp_mem 2020-11-09 15:34:44 -08:00
protocol.c
raw.c ipv6: raw: check passed optlen before reading 2021-12-29 12:32:56 -08:00
reassembly.c ipv6: record frag_max_size in atomic fragments in input path 2021-05-21 15:02:25 -07:00
route.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-02-17 11:44:20 -08:00
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 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-01-05 14:36:10 -08:00
seg6.c icmp: ICMPV6: Examine invoking packet for Segment Route Headers. 2022-01-04 12:17:35 +00:00
sit.c sit: allow encapsulated IPv6 traffic to be delivered locally 2022-01-12 13:56:07 -08:00
syncookies.c net: align static siphash keys 2021-11-16 19:07:54 -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 tcp: allocate tcp_death_row outside of struct netns_ipv4 2022-01-26 19:00:31 -08:00
tcpv6_offload.c net: move gro definitions to include/net/gro.h 2021-11-16 13:16:54 +00:00
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 gro: remove rcu_read_lock/rcu_read_unlock from gro_receive handlers 2021-11-24 17:21:42 -08:00
udp.c ipv6: Add reasons for skb drops to __udp6_lib_rcv 2022-02-14 11:24:39 +00:00
udplite.c net/ipv6: remove compat_ipv6_{get,set}sockopt 2020-07-19 18:16:41 -07:00
xfrm6_input.c
xfrm6_output.c net: ipv6: fix return value of ip6_skb_dst_mtu 2021-07-02 11:57:01 -07:00
xfrm6_policy.c ipv6: get rid of net->ipv6.rt6_stats->fib_rt_uncache 2022-02-11 11:44:27 +00:00
xfrm6_protocol.c
xfrm6_state.c
xfrm6_tunnel.c xfrm: remove description from xfrm_type struct 2021-06-09 09:38:52 +02:00