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d38afeec26
Originally, inet6_sk(sk)->XXX were changed under lock_sock(), so we were able to clean them up by calling inet6_destroy_sock() during the IPv6 -> IPv4 conversion by IPV6_ADDRFORM. However, commit03485f2adc("udpv6: Add lockless sendmsg() support") added a lockless memory allocation path, which could cause a memory leak: setsockopt(IPV6_ADDRFORM) sendmsg() +-----------------------+ +-------+ - do_ipv6_setsockopt(sk, ...) - udpv6_sendmsg(sk, ...) - sockopt_lock_sock(sk) ^._ called via udpv6_prot - lock_sock(sk) before WRITE_ONCE() - WRITE_ONCE(sk->sk_prot, &tcp_prot) - inet6_destroy_sock() - if (!corkreq) - sockopt_release_sock(sk) - ip6_make_skb(sk, ...) - release_sock(sk) ^._ lockless fast path for the non-corking case - __ip6_append_data(sk, ...) - ipv6_local_rxpmtu(sk, ...) - xchg(&np->rxpmtu, skb) ^._ rxpmtu is never freed. - goto out_no_dst; - lock_sock(sk) For now, rxpmtu is only the case, but not to miss the future change and a similar bug fixed in commite27326009a("net: ping6: Fix memleak in ipv6_renew_options()."), let's set a new function to IPv6 sk->sk_destruct() and call inet6_cleanup_sock() there. Since the conversion does not change sk->sk_destruct(), we can guarantee that we can clean up IPv6 resources finally. We can now remove all inet6_destroy_sock() calls from IPv6 protocol specific ->destroy() functions, but such changes are invasive to backport. So they can be posted as a follow-up later for net-next. Fixes:03485f2adc("udpv6: Add lockless sendmsg() support") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
135 lines
3.1 KiB
C
135 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* UDPLITE An implementation of the UDP-Lite protocol (RFC 3828).
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*
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* Authors: Gerrit Renker <gerrit@erg.abdn.ac.uk>
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*
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* Changes:
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* Fixes:
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*/
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#define pr_fmt(fmt) "UDPLite: " fmt
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#include <linux/export.h>
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#include <linux/proc_fs.h>
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#include "udp_impl.h"
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struct udp_table udplite_table __read_mostly;
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EXPORT_SYMBOL(udplite_table);
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/* Designate sk as UDP-Lite socket */
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static int udplite_sk_init(struct sock *sk)
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{
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udp_init_sock(sk);
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udp_sk(sk)->pcflag = UDPLITE_BIT;
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return 0;
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}
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static int udplite_rcv(struct sk_buff *skb)
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{
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return __udp4_lib_rcv(skb, &udplite_table, IPPROTO_UDPLITE);
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}
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static int udplite_err(struct sk_buff *skb, u32 info)
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{
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return __udp4_lib_err(skb, info, &udplite_table);
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}
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static const struct net_protocol udplite_protocol = {
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.handler = udplite_rcv,
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.err_handler = udplite_err,
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.no_policy = 1,
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};
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struct proto udplite_prot = {
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.name = "UDP-Lite",
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.owner = THIS_MODULE,
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.close = udp_lib_close,
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.connect = ip4_datagram_connect,
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.disconnect = udp_disconnect,
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.ioctl = udp_ioctl,
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.init = udplite_sk_init,
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.destroy = udp_destroy_sock,
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.setsockopt = udp_setsockopt,
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.getsockopt = udp_getsockopt,
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.sendmsg = udp_sendmsg,
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.recvmsg = udp_recvmsg,
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.sendpage = udp_sendpage,
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.hash = udp_lib_hash,
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.unhash = udp_lib_unhash,
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.rehash = udp_v4_rehash,
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.get_port = udp_v4_get_port,
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.memory_allocated = &udp_memory_allocated,
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.per_cpu_fw_alloc = &udp_memory_per_cpu_fw_alloc,
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.sysctl_mem = sysctl_udp_mem,
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.obj_size = sizeof(struct udp_sock),
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.h.udp_table = &udplite_table,
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};
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EXPORT_SYMBOL(udplite_prot);
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static struct inet_protosw udplite4_protosw = {
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.type = SOCK_DGRAM,
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.protocol = IPPROTO_UDPLITE,
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.prot = &udplite_prot,
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.ops = &inet_dgram_ops,
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.flags = INET_PROTOSW_PERMANENT,
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};
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#ifdef CONFIG_PROC_FS
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static struct udp_seq_afinfo udplite4_seq_afinfo = {
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.family = AF_INET,
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.udp_table = &udplite_table,
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};
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static int __net_init udplite4_proc_init_net(struct net *net)
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{
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if (!proc_create_net_data("udplite", 0444, net->proc_net, &udp_seq_ops,
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sizeof(struct udp_iter_state), &udplite4_seq_afinfo))
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return -ENOMEM;
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return 0;
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}
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static void __net_exit udplite4_proc_exit_net(struct net *net)
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{
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remove_proc_entry("udplite", net->proc_net);
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}
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static struct pernet_operations udplite4_net_ops = {
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.init = udplite4_proc_init_net,
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.exit = udplite4_proc_exit_net,
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};
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static __init int udplite4_proc_init(void)
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{
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return register_pernet_subsys(&udplite4_net_ops);
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}
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#else
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static inline int udplite4_proc_init(void)
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{
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return 0;
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}
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#endif
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void __init udplite4_register(void)
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{
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udp_table_init(&udplite_table, "UDP-Lite");
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if (proto_register(&udplite_prot, 1))
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goto out_register_err;
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if (inet_add_protocol(&udplite_protocol, IPPROTO_UDPLITE) < 0)
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goto out_unregister_proto;
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inet_register_protosw(&udplite4_protosw);
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if (udplite4_proc_init())
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pr_err("%s: Cannot register /proc!\n", __func__);
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return;
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out_unregister_proto:
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proto_unregister(&udplite_prot);
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out_register_err:
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pr_crit("%s: Cannot add UDP-Lite protocol\n", __func__);
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}
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