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| author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-04-21 09:45:37 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-04-28 13:16:35 -0700 |
| commit | f6d8bd051c391c1c0458a30b2a7abcd939329259 (patch) | |
| tree | 1dc4daecdeb0b42c2c6b59d7d6b41e091c11db5f /net/ipv4/inet_connection_sock.c | |
| parent | 0a14842f5a3c0e88a1e59fac5c3025db39721f74 (diff) | |
| download | linux-stable-f6d8bd051c391c1c0458a30b2a7abcd939329259.tar.gz linux-stable-f6d8bd051c391c1c0458a30b2a7abcd939329259.tar.bz2 linux-stable-f6d8bd051c391c1c0458a30b2a7abcd939329259.zip | |
inet: add RCU protection to inet->opt
We lack proper synchronization to manipulate inet->opt ip_options
Problem is ip_make_skb() calls ip_setup_cork() and
ip_setup_cork() possibly makes a copy of ipc->opt (struct ip_options),
without any protection against another thread manipulating inet->opt.
Another thread can change inet->opt pointer and free old one under us.
Use RCU to protect inet->opt (changed to inet->inet_opt).
Instead of handling atomic refcounts, just copy ip_options when
necessary, to avoid cache line dirtying.
We cant insert an rcu_head in struct ip_options since its included in
skb->cb[], so this patch is large because I had to introduce a new
ip_options_rcu structure.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/inet_connection_sock.c')
| -rw-r--r-- | net/ipv4/inet_connection_sock.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 8514db54a7f4..3282cb2de393 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -354,20 +354,20 @@ struct dst_entry *inet_csk_route_req(struct sock *sk, { struct rtable *rt; const struct inet_request_sock *ireq = inet_rsk(req); - struct ip_options *opt = inet_rsk(req)->opt; + struct ip_options_rcu *opt = inet_rsk(req)->opt; struct net *net = sock_net(sk); struct flowi4 fl4; flowi4_init_output(&fl4, sk->sk_bound_dev_if, sk->sk_mark, RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, sk->sk_protocol, inet_sk_flowi_flags(sk), - (opt && opt->srr) ? opt->faddr : ireq->rmt_addr, + (opt && opt->opt.srr) ? opt->opt.faddr : ireq->rmt_addr, ireq->loc_addr, ireq->rmt_port, inet_sk(sk)->inet_sport); security_req_classify_flow(req, flowi4_to_flowi(&fl4)); rt = ip_route_output_flow(net, &fl4, sk); if (IS_ERR(rt)) goto no_route; - if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) + if (opt && opt->opt.is_strictroute && rt->rt_dst != rt->rt_gateway) goto route_err; return &rt->dst; |