linux/net/ipv4
Eric Dumazet 686a7e32ca inetpeer: fix race in unused_list manipulations
Several crashes in cleanup_once() were reported in recent kernels.

Commit d6cc1d642d (inetpeer: various changes) added a race in
unlink_from_unused().

One way to avoid taking unused_peers.lock before doing the list_empty()
test is to catch 0->1 refcnt transitions, using full barrier atomic
operations variants (atomic_cmpxchg() and atomic_inc_return()) instead
of previous atomic_inc() and atomic_add_unless() variants.

We then call unlink_from_unused() only for the owner of the 0->1
transition.

Add a new atomic_add_unless_return() static helper

With help from Arun Sharma.

Refs: https://bugzilla.kernel.org/show_bug.cgi?id=32772

Reported-by: Arun Sharma <asharma@fb.com>
Reported-by: Maximilian Engelhardt <maxi@daemonizer.de>
Reported-by: Yann Dupont <Yann.Dupont@univ-nantes.fr>
Reported-by: Denys Fedoryshchenko <denys@visp.net.lb>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-27 13:39:11 -04:00
..
netfilter inet: constify ip headers and in6_addr 2011-04-22 11:04:14 -07:00
af_inet.c net: ipv4: add IPPROTO_ICMP socket kind 2011-05-13 16:08:13 -04:00
ah4.c inet: constify ip headers and in6_addr 2011-04-22 11:04:14 -07:00
arp.c net: gre: provide multicast mappings for ipv4 and ipv6 2011-03-30 00:10:47 -07:00
cipso_ipv4.c inet: add RCU protection to inet->opt 2011-04-28 13:16:35 -07:00
datagram.c ipv4: Lock socket and use cork flow in ip4_datagram_connect(). 2011-05-08 13:48:57 -07:00
devinet.c net: fix two lockdep splats 2011-05-10 15:03:01 -07:00
esp4.c inet: constify ip headers and in6_addr 2011-04-22 11:04:14 -07:00
fib_frontend.c Disable rp_filter for IPsec packets 2011-04-10 18:50:59 -07:00
fib_lookup.h ipv4: Fix nexthop caching wrt. scoping. 2011-03-24 18:06:47 -07:00
fib_rules.c
fib_semantics.c net,rcu: convert call_rcu(fc_rport_free_rcu) to kfree_rcu() 2011-05-07 22:50:55 -07:00
fib_trie.c Add appropriate <linux/prefetch.h> include for prefetch users 2011-05-22 21:41:57 -07:00
gre.c
icmp.c ipv4: Pass explicit destination address to rt_bind_peer(). 2011-05-18 18:42:43 -04:00
igmp.c igmp: call ip_mc_clear_src() only when we have no users of ip_mc_list 2011-05-24 13:26:12 -04:00
inet_connection_sock.c ipv4: Make caller provide flowi4 key to inet_csk_route_req(). 2011-05-18 18:32:03 -04:00
inet_diag.c inet: constify ip headers and in6_addr 2011-04-22 11:04:14 -07:00
inet_fragment.c
inet_hashtables.c
inet_lro.c inet: constify ip headers and in6_addr 2011-04-22 11:04:14 -07:00
inet_timewait_sock.c
inetpeer.c inetpeer: fix race in unused_list manipulations 2011-05-27 13:39:11 -04:00
ip_forward.c ipv4: Fix 'iph' use before set. 2011-05-12 23:03:46 -04:00
ip_fragment.c ipv4: Don't use enums as bitmasks in ip_fragment.c 2011-05-17 17:28:02 -04:00
ip_gre.c net: call dev_alloc_name from register_netdevice 2011-05-05 10:57:45 -07:00
ip_input.c inet: constify ip headers and in6_addr 2011-04-22 11:04:14 -07:00
ip_options.c ipv4: Remove rt->rt_dst reference from ip_forward_options(). 2011-05-13 17:31:02 -04:00
ip_output.c ipv4: Always call ip_options_build() after rest of IP header is filled in. 2011-05-13 17:21:27 -04:00
ip_sockglue.c inet: add RCU protection to inet->opt 2011-04-28 13:16:35 -07:00
ipcomp.c inet: constify ip headers and in6_addr 2011-04-22 11:04:14 -07:00
ipconfig.c ipconfig wait for carrier 2011-05-19 17:13:04 -04:00
ipip.c net: call dev_alloc_name from register_netdevice 2011-05-05 10:57:45 -07:00
ipmr.c ipv4: Pass explicit saddr/daddr args to ipmr_get_route(). 2011-05-04 12:18:54 -07:00
Kconfig
Makefile net: ipv4: add IPPROTO_ICMP socket kind 2011-05-13 16:08:13 -04:00
netfilter.c netfilter: af_info: add 'strict' parameter to limit lookup to .oif 2011-04-04 17:00:54 +02:00
ping.c net: ping: cleanups ping_v4_unhash() 2011-05-23 16:29:24 -04:00
proc.c
protocol.c
raw.c net: convert %p usage to %pK 2011-05-24 01:13:12 -04:00
route.c ipv4: Give backtrace in ip_rt_bug(). 2011-05-22 21:01:20 -04:00
syncookies.c inet: add RCU protection to inet->opt 2011-04-28 13:16:35 -07:00
sysctl_net_ipv4.c net: ping: fix build failure 2011-05-17 14:16:58 -04:00
tcp_bic.c
tcp_cong.c
tcp_cubic.c tcp_cubic: limit delayed_ack ratio to prevent divide error 2011-05-08 15:51:57 -07:00
tcp_diag.c
tcp_highspeed.c
tcp_htcp.c
tcp_hybla.c
tcp_illinois.c
tcp_input.c tcp: Make undo_ssthresh arg to tcp_undo_cwr() a bool. 2011-03-22 19:37:11 -07:00
tcp_ipv4.c net: convert %p usage to %pK 2011-05-24 01:13:12 -04:00
tcp_lp.c Fix common misspellings 2011-03-31 11:26:23 -03:00
tcp_minisocks.c
tcp_output.c inet: Pass flowi to ->queue_xmit(). 2011-05-08 15:28:28 -07:00
tcp_probe.c
tcp_scalable.c
tcp_timer.c
tcp_vegas.c
tcp_vegas.h
tcp_veno.c
tcp_westwood.c
tcp_yeah.c Fix common misspellings 2011-03-31 11:26:23 -03:00
tcp.c net: Allow no-cache copy from user on transmit 2011-04-04 22:30:30 -07:00
tunnel4.c
udp_impl.h
udp.c net: convert %p usage to %pK 2011-05-24 01:13:12 -04:00
udplite.c
xfrm4_input.c
xfrm4_mode_beet.c
xfrm4_mode_transport.c
xfrm4_mode_tunnel.c
xfrm4_output.c xfrm: Assign the inner mode output function to the dst entry 2011-05-10 15:03:34 -07:00
xfrm4_policy.c ipv4: xfrm: Eliminate ->rt_src reference in policy code. 2011-05-10 13:32:48 -07:00
xfrm4_state.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-3.6 2011-05-11 14:26:58 -04:00
xfrm4_tunnel.c