6.5-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
commit f5f80e32de12fad2813d37270e8364a03e6d3ef0 upstream.
IPv6 inet sockets are supposed to have a "struct ipv6_pinfo" field at the end of their definition, so that inet6_sk_generic() can derive from socket size the offset of the "struct ipv6_pinfo".
This is very fragile, and prevents adding bigger alignment in sockets, because inet6_sk_generic() does not work if the compiler adds padding after the ipv6_pinfo component.
We are currently working on a patch series to reorganize TCP structures for better data locality and found issues similar to the one fixed in commit f5d547676ca0 ("tcp: fix tcp_inet6_sk() for 32bit kernels")
Alternative would be to force an alignment on "struct ipv6_pinfo", greater or equal to __alignof__(any ipv6 sock) to ensure there is no padding. This does not look great.
v2: fix typo in mptcp_proto_v6_init() (Paolo)
Signed-off-by: Eric Dumazet edumazet@google.com Cc: Chao Wu wwchao@google.com Cc: Wei Wang weiwan@google.com Cc: Coco Li lixiaoyan@google.com Cc: YiFei Zhu zhuyifei@google.com Reviewed-by: Simon Horman simon.horman@corigine.com Signed-off-by: David S. Miller davem@davemloft.net Cc: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/linux/ipv6.h | 15 ++++----------- include/net/sock.h | 1 + net/dccp/ipv6.c | 1 + net/dccp/ipv6.h | 4 ---- net/ipv6/af_inet6.c | 4 ++-- net/ipv6/ping.c | 1 + net/ipv6/raw.c | 1 + net/ipv6/tcp_ipv6.c | 1 + net/ipv6/udp.c | 1 + net/ipv6/udplite.c | 1 + net/l2tp/l2tp_ip6.c | 4 +--- net/mptcp/protocol.c | 1 + net/sctp/socket.c | 1 + 13 files changed, 16 insertions(+), 20 deletions(-)
--- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -199,14 +199,7 @@ struct inet6_cork { u8 tclass; };
-/** - * struct ipv6_pinfo - ipv6 private area - * - * In the struct sock hierarchy (tcp6_sock, upd6_sock, etc) - * this _must_ be the last member, so that inet6_sk_generic - * is able to calculate its offset from the base struct sock - * by using the struct proto->slab_obj_size member. -acme - */ +/* struct ipv6_pinfo - ipv6 private area */ struct ipv6_pinfo { struct in6_addr saddr; struct in6_pktinfo sticky_pktinfo; @@ -306,19 +299,19 @@ struct raw6_sock { __u32 offset; /* checksum offset */ struct icmp6_filter filter; __u32 ip6mr_table; - /* ipv6_pinfo has to be the last member of raw6_sock, see inet6_sk_generic */ + struct ipv6_pinfo inet6; };
struct udp6_sock { struct udp_sock udp; - /* ipv6_pinfo has to be the last member of udp6_sock, see inet6_sk_generic */ + struct ipv6_pinfo inet6; };
struct tcp6_sock { struct tcp_sock tcp; - /* ipv6_pinfo has to be the last member of tcp6_sock, see inet6_sk_generic */ + struct ipv6_pinfo inet6; };
--- a/include/net/sock.h +++ b/include/net/sock.h @@ -1340,6 +1340,7 @@ struct proto {
struct kmem_cache *slab; unsigned int obj_size; + unsigned int ipv6_pinfo_offset; slab_flags_t slab_flags; unsigned int useroffset; /* Usercopy region offset */ unsigned int usersize; /* Usercopy region size */ --- a/net/dccp/ipv6.c +++ b/net/dccp/ipv6.c @@ -1056,6 +1056,7 @@ static struct proto dccp_v6_prot = { .orphan_count = &dccp_orphan_count, .max_header = MAX_DCCP_HEADER, .obj_size = sizeof(struct dccp6_sock), + .ipv6_pinfo_offset = offsetof(struct dccp6_sock, inet6), .slab_flags = SLAB_TYPESAFE_BY_RCU, .rsk_prot = &dccp6_request_sock_ops, .twsk_prot = &dccp6_timewait_sock_ops, --- a/net/dccp/ipv6.h +++ b/net/dccp/ipv6.h @@ -13,10 +13,6 @@
struct dccp6_sock { struct dccp_sock dccp; - /* - * ipv6_pinfo has to be the last member of dccp6_sock, - * see inet6_sk_generic. - */ struct ipv6_pinfo inet6; };
--- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -102,9 +102,9 @@ bool ipv6_mod_enabled(void) } EXPORT_SYMBOL_GPL(ipv6_mod_enabled);
-static __inline__ struct ipv6_pinfo *inet6_sk_generic(struct sock *sk) +static struct ipv6_pinfo *inet6_sk_generic(struct sock *sk) { - const int offset = sk->sk_prot->obj_size - sizeof(struct ipv6_pinfo); + const int offset = sk->sk_prot->ipv6_pinfo_offset;
return (struct ipv6_pinfo *)(((u8 *)sk) + offset); } --- a/net/ipv6/ping.c +++ b/net/ipv6/ping.c @@ -215,6 +215,7 @@ struct proto pingv6_prot = { .get_port = ping_get_port, .put_port = ping_unhash, .obj_size = sizeof(struct raw6_sock), + .ipv6_pinfo_offset = offsetof(struct raw6_sock, inet6), }; EXPORT_SYMBOL_GPL(pingv6_prot);
--- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -1216,6 +1216,7 @@ struct proto rawv6_prot = { .hash = raw_hash_sk, .unhash = raw_unhash_sk, .obj_size = sizeof(struct raw6_sock), + .ipv6_pinfo_offset = offsetof(struct raw6_sock, inet6), .useroffset = offsetof(struct raw6_sock, filter), .usersize = sizeof_field(struct raw6_sock, filter), .h.raw_hash = &raw_v6_hashinfo, --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -2176,6 +2176,7 @@ struct proto tcpv6_prot = { .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem), .max_header = MAX_TCP_HEADER, .obj_size = sizeof(struct tcp6_sock), + .ipv6_pinfo_offset = offsetof(struct tcp6_sock, inet6), .slab_flags = SLAB_TYPESAFE_BY_RCU, .twsk_prot = &tcp6_timewait_sock_ops, .rsk_prot = &tcp6_request_sock_ops, --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1802,6 +1802,7 @@ struct proto udpv6_prot = { .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min), .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min), .obj_size = sizeof(struct udp6_sock), + .ipv6_pinfo_offset = offsetof(struct udp6_sock, inet6), .h.udp_table = NULL, .diag_destroy = udp_abort, }; --- a/net/ipv6/udplite.c +++ b/net/ipv6/udplite.c @@ -67,6 +67,7 @@ struct proto udplitev6_prot = { .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min), .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min), .obj_size = sizeof(struct udp6_sock), + .ipv6_pinfo_offset = offsetof(struct udp6_sock, inet6), .h.udp_table = &udplite_table, };
--- a/net/l2tp/l2tp_ip6.c +++ b/net/l2tp/l2tp_ip6.c @@ -36,9 +36,6 @@ struct l2tp_ip6_sock { u32 conn_id; u32 peer_conn_id;
- /* ipv6_pinfo has to be the last member of l2tp_ip6_sock, see - * inet6_sk_generic - */ struct ipv6_pinfo inet6; };
@@ -730,6 +727,7 @@ static struct proto l2tp_ip6_prot = { .hash = l2tp_ip6_hash, .unhash = l2tp_ip6_unhash, .obj_size = sizeof(struct l2tp_ip6_sock), + .ipv6_pinfo_offset = offsetof(struct l2tp_ip6_sock, inet6), };
static const struct proto_ops l2tp_ip6_ops = { --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -3987,6 +3987,7 @@ int __init mptcp_proto_v6_init(void) strcpy(mptcp_v6_prot.name, "MPTCPv6"); mptcp_v6_prot.slab = NULL; mptcp_v6_prot.obj_size = sizeof(struct mptcp6_sock); + mptcp_v6_prot.ipv6_pinfo_offset = offsetof(struct mptcp6_sock, np);
err = proto_register(&mptcp_v6_prot, 1); if (err) --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -9732,6 +9732,7 @@ struct proto sctpv6_prot = { .unhash = sctp_unhash, .no_autobind = true, .obj_size = sizeof(struct sctp6_sock), + .ipv6_pinfo_offset = offsetof(struct sctp6_sock, inet6), .useroffset = offsetof(struct sctp6_sock, sctp.subscribe), .usersize = offsetof(struct sctp6_sock, sctp.initmsg) - offsetof(struct sctp6_sock, sctp.subscribe) +