linux/net/ipv6
Eric Dumazet b357a364c5 inet: fix possible panic in reqsk_queue_unlink()
[ 3897.923145] BUG: unable to handle kernel NULL pointer dereference at
 0000000000000080
[ 3897.931025] IP: [<ffffffffa9f27686>] reqsk_timer_handler+0x1a6/0x243

There is a race when reqsk_timer_handler() and tcp_check_req() call
inet_csk_reqsk_queue_unlink() on the same req at the same time.

Before commit fa76ce7328 ("inet: get rid of central tcp/dccp listener
timer"), listener spinlock was held and race could not happen.

To solve this bug, we change reqsk_queue_unlink() to not assume req
must be found, and we return a status, to conditionally release a
refcount on the request sock.

This also means tcp_check_req() in non fastopen case might or not
consume req refcount, so tcp_v6_hnd_req() & tcp_v4_hnd_req() have
to properly handle this.

(Same remark for dccp_check_req() and its callers)

inet_csk_reqsk_queue_drop() is now too big to be inlined, as it is
called 4 times in tcp and 3 times in dccp.

Fixes: fa76ce7328 ("inet: get rid of central tcp/dccp listener timer")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-24 11:39:15 -04:00
..
netfilter netfilter: nf_tables: switch registers to 32 bit addressing 2015-04-13 17:17:29 +02:00
addrconf_core.c ipv6: coding style: comparison for inequality with NULL 2015-03-31 13:51:54 -04:00
addrconf.c dev: introduce dev_get_iflink() 2015-04-02 14:04:59 -04:00
addrlabel.c netlink: implement nla_put_in_addr and nla_put_in6_addr 2015-03-31 13:58:35 -04:00
af_inet6.c ipv6: coding style: comparison for inequality with NULL 2015-03-31 13:51:54 -04:00
ah6.c ipv6: coding style: comparison for equality with NULL 2015-03-31 13:51:54 -04:00
anycast.c ipv6: coding style: comparison for equality with NULL 2015-03-31 13:51:54 -04:00
datagram.c ipv6: coding style: comparison for equality with NULL 2015-03-31 13:51:54 -04:00
esp6.c ipv6: coding style: comparison for equality with NULL 2015-03-31 13:51:54 -04:00
exthdrs_core.c ipv6: coding style: comparison for equality with NULL 2015-03-31 13:51:54 -04:00
exthdrs_offload.c ipv6: Fix exthdrs offload registration. 2014-03-06 16:35:55 -05:00
exthdrs.c net: Convert LIMIT_NETDEBUG to net_dbg_ratelimited 2014-11-11 14:10:31 -05:00
fib6_rules.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-04-06 22:34:15 -04:00
icmp.c ipv6: coding style: comparison for equality with NULL 2015-03-31 13:51:54 -04:00
inet6_connection_sock.c net: convert syn_wait_lock to a spinlock 2015-03-23 16:52:26 -04:00
inet6_hashtables.c tcp/dccp: get rid of central timewait timer 2015-04-13 16:40:05 -04:00
ip6_checksum.c udp: Generic functions to set checksum 2014-06-04 22:46:38 -07:00
ip6_fib.c ipv6: coding style: comparison for inequality with NULL 2015-03-31 13:51:54 -04:00
ip6_flowlabel.c ipv6: coding style: comparison for inequality with NULL 2015-03-31 13:51:54 -04:00
ip6_gre.c ip6_gre: use netdev_alloc_pcpu_stats() 2015-04-22 15:39:05 -04:00
ip6_icmp.c ipv6: White-space cleansing : Line Layouts 2014-08-24 22:37:52 -07:00
ip6_input.c netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
ip6_offload.c ipv6: coding style: comparison for inequality with NULL 2015-03-31 13:51:54 -04:00
ip6_offload.h ipv6: Pull IPv6 GSO registration out of the module 2012-11-15 17:39:24 -05:00
ip6_output.c netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
ip6_tunnel.c udp_tunnel: Pass UDP socket down through udp_tunnel{, 6}_xmit_skb(). 2015-04-07 15:29:08 -04:00
ip6_udp_tunnel.c udp_tunnel: Pass UDP socket down through udp_tunnel{, 6}_xmit_skb(). 2015-04-07 15:29:08 -04:00
ip6_vti.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-04-14 15:44:14 -04:00
ip6mr.c netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
ipcomp6.c ipv6: White-space cleansing : Structure layouts 2014-08-24 22:37:52 -07:00
ipv6_sockglue.c ipv6: coding style: comparison for equality with NULL 2015-03-31 13:51:54 -04:00
Kconfig ip6_vti: Fix build when NET_IP_TUNNEL is not set. 2014-02-20 14:29:49 +01:00
Makefile udp_tunnel: Only build ip6_udp_tunnel.c when IPV6 is selected 2014-09-19 22:05:28 -04:00
mcast.c netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
mip6.c net: Convert LIMIT_NETDEBUG to net_dbg_ratelimited 2014-11-11 14:10:31 -05:00
ndisc.c netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
netfilter.c netfilter: Use nf_hook_state in nf_queue_entry. 2015-04-04 12:25:22 -04:00
output_core.c udp_tunnel: Pass UDP socket down through udp_tunnel{, 6}_xmit_skb(). 2015-04-07 15:29:08 -04:00
ping.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-03-09 23:38:02 -04:00
proc.c udp: Increment UDP_MIB_IGNOREDMULTI for arriving unmatched multicasts 2014-11-07 15:45:50 -05:00
protocol.c net: Export inet_offloads and inet6_offloads 2014-09-19 17:15:31 -04:00
raw.c netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
reassembly.c ipv6: coding style: comparison for inequality with NULL 2015-03-31 13:51:54 -04:00
route.c netlink: implement nla_get_in_addr and nla_get_in6_addr 2015-03-31 13:58:35 -04:00
sit.c ipv6: call iptunnel_xmit with NULL sock pointer if no tunnel sock is available 2015-04-08 12:09:43 -04:00
syncookies.c tcp: fix ipv4 mapped request socks 2015-03-25 00:57:48 -04:00
sysctl_net_ipv6.c ipv6: coding style: comparison for equality with NULL 2015-03-31 13:51:54 -04:00
tcp_ipv6.c inet: fix possible panic in reqsk_queue_unlink() 2015-04-24 11:39:15 -04:00
tcpv6_offload.c tcp: cleanup static functions 2015-02-28 16:56:51 -05:00
tunnel6.c ipv6: White-space cleansing : gaps between function and symbol export 2014-08-24 22:37:52 -07:00
udp_impl.h net: Remove iocb argument from sendmsg and recvmsg 2015-03-02 13:06:31 -05:00
udp_offload.c ipv6: hash net ptr into fragmentation bucket selection 2015-03-25 14:07:04 -04:00
udp.c net: remove extra newlines 2015-04-07 22:24:37 -04:00
udplite.c net: Eliminate no_check from protosw 2014-05-23 16:28:53 -04:00
xfrm6_input.c netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
xfrm6_mode_beet.c xfrm: simplify xfrm_address_t use 2015-03-31 13:58:35 -04:00
xfrm6_mode_ro.c ipv4/ipv6: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
xfrm6_mode_transport.c
xfrm6_mode_tunnel.c xfrm6: Remove xfrm_tunnel_notifier 2014-03-14 07:28:08 +01:00
xfrm6_output.c netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
xfrm6_policy.c xfrm: simplify xfrm_address_t use 2015-03-31 13:58:35 -04:00
xfrm6_protocol.c xfrm6: Properly handle unsupported protocols 2014-05-06 07:08:38 +02:00
xfrm6_state.c ipv6: White-space cleansing : Line Layouts 2014-08-24 22:37:52 -07:00
xfrm6_tunnel.c ipv6: White-space cleansing : gaps between function and symbol export 2014-08-24 22:37:52 -07:00