android_kernel_samsung_msm8976/net/ipv6/udplite.c
Eric Dumazet f77d602124 ipv6: do not clear pinet6 field
We have seen multiple NULL dereferences in __inet6_lookup_established()

After analysis, I found that inet6_sk() could be NULL while the
check for sk_family == AF_INET6 was true.

Bug was added in linux-2.6.29 when RCU lookups were introduced in UDP
and TCP stacks.

Once an IPv6 socket, using SLAB_DESTROY_BY_RCU is inserted in a hash
table, we no longer can clear pinet6 field.

This patch extends logic used in commit fcbdf09d96
("net: fix nulls list corruptions in sk_prot_alloc")

TCP/UDP/UDPLite IPv6 protocols provide their own .clear_sk() method
to make sure we do not clear pinet6 field.

At socket clone phase, we do not really care, as cloning the parent (non
NULL) pinet6 is not adding a fatal race.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-11 16:26:38 -07:00

140 lines
3.4 KiB
C

/*
* UDPLITEv6 An implementation of the UDP-Lite protocol over IPv6.
* See also net/ipv4/udplite.c
*
* Authors: Gerrit Renker <gerrit@erg.abdn.ac.uk>
*
* Changes:
* Fixes:
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/export.h>
#include "udp_impl.h"
static int udplitev6_rcv(struct sk_buff *skb)
{
return __udp6_lib_rcv(skb, &udplite_table, IPPROTO_UDPLITE);
}
static void udplitev6_err(struct sk_buff *skb,
struct inet6_skb_parm *opt,
u8 type, u8 code, int offset, __be32 info)
{
__udp6_lib_err(skb, opt, type, code, offset, info, &udplite_table);
}
static const struct inet6_protocol udplitev6_protocol = {
.handler = udplitev6_rcv,
.err_handler = udplitev6_err,
.flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
};
struct proto udplitev6_prot = {
.name = "UDPLITEv6",
.owner = THIS_MODULE,
.close = udp_lib_close,
.connect = ip6_datagram_connect,
.disconnect = udp_disconnect,
.ioctl = udp_ioctl,
.init = udplite_sk_init,
.destroy = udpv6_destroy_sock,
.setsockopt = udpv6_setsockopt,
.getsockopt = udpv6_getsockopt,
.sendmsg = udpv6_sendmsg,
.recvmsg = udpv6_recvmsg,
.backlog_rcv = udpv6_queue_rcv_skb,
.hash = udp_lib_hash,
.unhash = udp_lib_unhash,
.get_port = udp_v6_get_port,
.obj_size = sizeof(struct udp6_sock),
.slab_flags = SLAB_DESTROY_BY_RCU,
.h.udp_table = &udplite_table,
#ifdef CONFIG_COMPAT
.compat_setsockopt = compat_udpv6_setsockopt,
.compat_getsockopt = compat_udpv6_getsockopt,
#endif
.clear_sk = udp_v6_clear_sk,
};
static struct inet_protosw udplite6_protosw = {
.type = SOCK_DGRAM,
.protocol = IPPROTO_UDPLITE,
.prot = &udplitev6_prot,
.ops = &inet6_dgram_ops,
.no_check = 0,
.flags = INET_PROTOSW_PERMANENT,
};
int __init udplitev6_init(void)
{
int ret;
ret = inet6_add_protocol(&udplitev6_protocol, IPPROTO_UDPLITE);
if (ret)
goto out;
ret = inet6_register_protosw(&udplite6_protosw);
if (ret)
goto out_udplitev6_protocol;
out:
return ret;
out_udplitev6_protocol:
inet6_del_protocol(&udplitev6_protocol, IPPROTO_UDPLITE);
goto out;
}
void udplitev6_exit(void)
{
inet6_unregister_protosw(&udplite6_protosw);
inet6_del_protocol(&udplitev6_protocol, IPPROTO_UDPLITE);
}
#ifdef CONFIG_PROC_FS
static const struct file_operations udplite6_afinfo_seq_fops = {
.owner = THIS_MODULE,
.open = udp_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_net
};
static struct udp_seq_afinfo udplite6_seq_afinfo = {
.name = "udplite6",
.family = AF_INET6,
.udp_table = &udplite_table,
.seq_fops = &udplite6_afinfo_seq_fops,
.seq_ops = {
.show = udp6_seq_show,
},
};
static int __net_init udplite6_proc_init_net(struct net *net)
{
return udp_proc_register(net, &udplite6_seq_afinfo);
}
static void __net_exit udplite6_proc_exit_net(struct net *net)
{
udp_proc_unregister(net, &udplite6_seq_afinfo);
}
static struct pernet_operations udplite6_net_ops = {
.init = udplite6_proc_init_net,
.exit = udplite6_proc_exit_net,
};
int __init udplite6_proc_init(void)
{
return register_pernet_subsys(&udplite6_net_ops);
}
void udplite6_proc_exit(void)
{
unregister_pernet_subsys(&udplite6_net_ops);
}
#endif