diff options
author | Eric Dumazet <edumazet@google.com> | 2013-05-09 14:28:16 +0400 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2013-05-12 03:26:38 +0400 |
commit | f77d602124d865c38705df7fa25c03de9c284ad2 (patch) | |
tree | 173c11c4c8bfe13a891dcee6bf546c2bc4c9ed76 /net | |
parent | 233c7df0821c4190e2d3f4be0f2ca0ab40a5ed8c (diff) | |
download | linux-f77d602124d865c38705df7fa25c03de9c284ad2.tar.xz |
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 fcbdf09d9652c891
("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>
Diffstat (limited to 'net')
-rw-r--r-- | net/core/sock.c | 12 | ||||
-rw-r--r-- | net/ipv6/tcp_ipv6.c | 12 | ||||
-rw-r--r-- | net/ipv6/udp.c | 13 | ||||
-rw-r--r-- | net/ipv6/udp_impl.h | 2 | ||||
-rw-r--r-- | net/ipv6/udplite.c | 2 |
5 files changed, 27 insertions, 14 deletions
diff --git a/net/core/sock.c b/net/core/sock.c index d4f4cea726e7..6ba327da79e1 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1217,18 +1217,6 @@ static void sock_copy(struct sock *nsk, const struct sock *osk) #endif } -/* - * caches using SLAB_DESTROY_BY_RCU should let .next pointer from nulls nodes - * un-modified. Special care is taken when initializing object to zero. - */ -static inline void sk_prot_clear_nulls(struct sock *sk, int size) -{ - if (offsetof(struct sock, sk_node.next) != 0) - memset(sk, 0, offsetof(struct sock, sk_node.next)); - memset(&sk->sk_node.pprev, 0, - size - offsetof(struct sock, sk_node.pprev)); -} - void sk_prot_clear_portaddr_nulls(struct sock *sk, int size) { unsigned long nulls1, nulls2; diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 71167069b394..0a17ed9eaf39 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1890,6 +1890,17 @@ void tcp6_proc_exit(struct net *net) } #endif +static void tcp_v6_clear_sk(struct sock *sk, int size) +{ + struct inet_sock *inet = inet_sk(sk); + + /* we do not want to clear pinet6 field, because of RCU lookups */ + sk_prot_clear_nulls(sk, offsetof(struct inet_sock, pinet6)); + + size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6); + memset(&inet->pinet6 + 1, 0, size); +} + struct proto tcpv6_prot = { .name = "TCPv6", .owner = THIS_MODULE, @@ -1933,6 +1944,7 @@ struct proto tcpv6_prot = { #ifdef CONFIG_MEMCG_KMEM .proto_cgroup = tcp_proto_cgroup, #endif + .clear_sk = tcp_v6_clear_sk, }; static const struct inet6_protocol tcpv6_protocol = { diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index d4defdd44937..42923b14dfa6 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1432,6 +1432,17 @@ void udp6_proc_exit(struct net *net) { } #endif /* CONFIG_PROC_FS */ +void udp_v6_clear_sk(struct sock *sk, int size) +{ + struct inet_sock *inet = inet_sk(sk); + + /* we do not want to clear pinet6 field, because of RCU lookups */ + sk_prot_clear_portaddr_nulls(sk, offsetof(struct inet_sock, pinet6)); + + size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6); + memset(&inet->pinet6 + 1, 0, size); +} + /* ------------------------------------------------------------------------ */ struct proto udpv6_prot = { @@ -1462,7 +1473,7 @@ struct proto udpv6_prot = { .compat_setsockopt = compat_udpv6_setsockopt, .compat_getsockopt = compat_udpv6_getsockopt, #endif - .clear_sk = sk_prot_clear_portaddr_nulls, + .clear_sk = udp_v6_clear_sk, }; static struct inet_protosw udpv6_protosw = { diff --git a/net/ipv6/udp_impl.h b/net/ipv6/udp_impl.h index d7571046bfc4..4691ed50a928 100644 --- a/net/ipv6/udp_impl.h +++ b/net/ipv6/udp_impl.h @@ -31,6 +31,8 @@ extern int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk, extern int udpv6_queue_rcv_skb(struct sock * sk, struct sk_buff *skb); extern void udpv6_destroy_sock(struct sock *sk); +extern void udp_v6_clear_sk(struct sock *sk, int size); + #ifdef CONFIG_PROC_FS extern int udp6_seq_show(struct seq_file *seq, void *v); #endif diff --git a/net/ipv6/udplite.c b/net/ipv6/udplite.c index 1d08e21d9f69..dfcc4be46898 100644 --- a/net/ipv6/udplite.c +++ b/net/ipv6/udplite.c @@ -56,7 +56,7 @@ struct proto udplitev6_prot = { .compat_setsockopt = compat_udpv6_setsockopt, .compat_getsockopt = compat_udpv6_getsockopt, #endif - .clear_sk = sk_prot_clear_portaddr_nulls, + .clear_sk = udp_v6_clear_sk, }; static struct inet_protosw udplite6_protosw = { |