linux/net/ipv6
Taehee Yoo 4b4b84468a mld: change lockdep annotation for ip6_sf_socklist and ipv6_mc_socklist
struct ip6_sf_socklist and ipv6_mc_socklist are per-socket MLD data.
These data are protected by rtnl lock, socket lock, and RCU.
So, when these are used, it verifies whether rtnl lock is acquired or not.

ip6_mc_msfget() is called by do_ipv6_getsockopt().
But caller doesn't acquire rtnl lock.
So, when these data are used in the ip6_mc_msfget() lockdep warns about it.
But accessing these is actually safe because socket lock was acquired by
do_ipv6_getsockopt().

So, it changes lockdep annotation from rtnl lock to socket lock.
(rtnl_dereference -> sock_dereference)

Locking graph for mld data is like below:

When writing mld data:
do_ipv6_setsockopt()
    rtnl_lock
    lock_sock
    (mld functions)
        idev->mc_lock(if per-interface mld data is modified)

When reading mld data:
do_ipv6_getsockopt()
    lock_sock
    ip6_mc_msfget()

Splat looks like:
=============================
WARNING: suspicious RCU usage
5.12.0-rc4+ #503 Not tainted
-----------------------------
net/ipv6/mcast.c:610 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
1 lock held by mcast-listener-/923:
 #0: ffff888007958a70 (sk_lock-AF_INET6){+.+.}-{0:0}, at:
ipv6_get_msfilter+0xaf/0x190

stack backtrace:
CPU: 1 PID: 923 Comm: mcast-listener- Not tainted 5.12.0-rc4+ #503
Call Trace:
 dump_stack+0xa4/0xe5
 ip6_mc_msfget+0x553/0x6c0
 ? ipv6_sock_mc_join_ssm+0x10/0x10
 ? lockdep_hardirqs_on_prepare+0x3e0/0x3e0
 ? mark_held_locks+0xb7/0x120
 ? lockdep_hardirqs_on_prepare+0x27c/0x3e0
 ? __local_bh_enable_ip+0xa5/0xf0
 ? lock_sock_nested+0x82/0xf0
 ipv6_get_msfilter+0xc3/0x190
 ? compat_ipv6_get_msfilter+0x300/0x300
 ? lock_downgrade+0x690/0x690
 do_ipv6_getsockopt.isra.6.constprop.13+0x1809/0x29e0
 ? do_ipv6_mcast_group_source+0x150/0x150
 ? register_lock_class+0x1750/0x1750
 ? kvm_sched_clock_read+0x14/0x30
 ? sched_clock+0x5/0x10
 ? sched_clock_cpu+0x18/0x170
 ? find_held_lock+0x3a/0x1c0
 ? lock_downgrade+0x690/0x690
 ? ipv6_getsockopt+0xdb/0x1b0
 ipv6_getsockopt+0xdb/0x1b0
[ ... ]

Fixes: 88e2ca3080 ("mld: convert ifmcaddr6 to RCU")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-05 12:50:04 -07:00
..
ila net: Add MODULE_DESCRIPTION entries to network modules 2020-06-20 21:33:57 -07:00
netfilter Revert "netfilter: x_tables: Switch synchronization to RCU" 2021-03-15 18:42:01 +01:00
addrconf_core.c ipv6: add ipv6_dev_find to stubs 2021-03-30 13:29:39 -07:00
addrconf.c ipv6: addrconf.c: Fix a typo 2021-03-28 17:31:13 -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 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-04-02 11:03:07 -07:00
ah6.c ah6: fix error return code in ah6_input() 2020-11-18 10:53:16 -08:00
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: Add MODULE_DESCRIPTION entries to network modules 2020-06-20 21:33:57 -07:00
esp6.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2021-02-09 11:23:41 -08:00
exthdrs_core.c
exthdrs_offload.c
exthdrs.c seg6: add support for IPv4 decapsulation in ipv6_srh_rcv() 2021-03-11 16:09:21 -08:00
fib6_notifier.c
fib6_rules.c fib: use indirect call wrappers in the most common fib_rules_ops 2020-07-28 17:42:31 -07:00
fou6.c net: Add MODULE_DESCRIPTION entries to network modules 2020-06-20 21:33:57 -07:00
icmp.c ipv6: convert elligible sysctls to u8 2021-03-31 14:48:20 -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: ipv6: remove unused arg exact_dif in compute_score 2020-08-31 13:08:10 -07:00
ip6_checksum.c
ip6_fib.c ipv6: fix suspecious RCU usage warning 2021-03-10 12:35:23 -08:00
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 ipv6: remove extra dev_hold() for fallback tunnels 2021-03-31 14:53:11 -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 net/core: move gro function declarations to separate header 2021-02-04 18:37:57 -08:00
ip6_offload.h
ip6_output.c net: use indirect call helpers for dst_output 2021-02-03 14:51:39 -08:00
ip6_tunnel.c ipv6: remove extra dev_hold() for fallback tunnels 2021-03-31 14:53:11 -07:00
ip6_udp_tunnel.c net: Make locking in sock_bindtoindex optional 2020-06-01 14:57:14 -07:00
ip6_vti.c ipv6: remove extra dev_hold() for fallback tunnels 2021-03-31 14:53:11 -07:00
ip6mr.c net/ipv6: switch ip6_mroute_setsockopt to sockptr_t 2020-07-24 15:41:54 -07:00
ipcomp6.c ipcomp: assign if_id to child tunnel from parent tunnel 2020-07-09 12:55:37 +02:00
ipv6_sockglue.c net/ipv6: propagate user pointer annotation 2020-12-01 11:42:33 -08:00
Kconfig net: ipv6: fix kconfig dependency warning for IPV6_SEG6_HMAC 2020-09-18 17:45:04 -07:00
Makefile
mcast_snoop.c
mcast.c mld: change lockdep annotation for ip6_sf_socklist and ipv6_mc_socklist 2021-04-05 12:50:04 -07:00
mip6.c
ndisc.c net: allow user to set metric on default route learned via Router Advertisement 2021-01-26 18:39:45 -08:00
netfilter.c netfilter: use actual socket sk rather than skb sk when routing harder 2020-10-30 12:57:39 +01:00
output_core.c
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 lsm,selinux: pass flowi_common instead of flowi to the LSM hooks 2020-11-23 18:36:21 -05:00
reassembly.c ipv6: Remove dependency of ipv6_frag_thdr_truncated on ipv6 module 2020-11-19 10:49:50 -08:00
route.c net: ipv6: Refactor in rt6_age_examine_exception 2021-04-01 15:45:26 -07:00
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 crypto: sha - split sha.h into sha1.h and sha2.h 2020-11-20 14:45:33 +11:00
seg6_iptunnel.c seg6_iptunnel: Refactor seg6_lwt_headroom out of uapi header 2020-08-03 17:57:40 -07:00
seg6_local.c seg6: ignore routing header with segments left equal to 0 2021-03-11 16:09:21 -08:00
seg6.c seg6: fix seg6_validate_srh() to avoid slab-out-of-bounds 2020-06-04 15:39:32 -07:00
sit.c ipv6: remove extra dev_hold() for fallback tunnels 2021-03-31 14:53:11 -07:00
syncookies.c selinux/stable-5.11 PR 20201214 2020-12-16 11:01:04 -08:00
sysctl_net_ipv6.c ipv6: convert elligible sysctls to u8 2021-03-31 14:48:20 -07:00
tcp_ipv6.c mptcp: add mptcp reset option support 2021-04-02 14:21:50 -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 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-04-02 11:03:07 -07:00
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 xfrm: remove output_finish indirection from xfrm_state_afinfo 2020-05-06 09:40:08 +02:00
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: interface: fix the priorities for ipip and ipv6 tunnels 2020-10-09 12:29:48 +02:00