diff options
| author | Eric Dumazet <edumazet@google.com> | 2018-10-02 12:35:05 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-10-18 09:13:23 +0200 |
| commit | 6b2f36b94a0d57f5378742d482f4e46ae0acd78a (patch) | |
| tree | d6b3862a9418758cd1e9c0ef8413cd7e11453d68 | |
| parent | 4cded0a3a9c69d3c08b2ab15a7dd8206775142e4 (diff) | |
inet: make sure to grab rcu_read_lock before using ireq->ireq_opt
[ Upstream commit 2ab2ddd301a22ca3c5f0b743593e4ad2953dfa53 ]
Timer handlers do not imply rcu_read_lock(), so my recent fix
triggered a LOCKDEP warning when SYNACK is retransmit.
Lets add rcu_read_lock()/rcu_read_unlock() pairs around ireq->ireq_opt
usages instead of guessing what is done by callers, since it is
not worth the pain.
Get rid of ireq_opt_deref() helper since it hides the logic
without real benefit, since it is now a standard rcu_dereference().
Fixes: 1ad98e9d1bdf ("tcp/dccp: fix lockdep issue when SYN is backlogged")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | include/net/inet_sock.h | 5 | ||||
| -rw-r--r-- | net/dccp/ipv4.c | 4 | ||||
| -rw-r--r-- | net/ipv4/inet_connection_sock.c | 5 | ||||
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 4 |
4 files changed, 10 insertions, 8 deletions
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h index 02255bf8c4d2..6213a90a8cec 100644 --- a/include/net/inet_sock.h +++ b/include/net/inet_sock.h @@ -132,11 +132,6 @@ static inline int inet_request_bound_dev_if(const struct sock *sk, return sk->sk_bound_dev_if; } -static inline struct ip_options_rcu *ireq_opt_deref(const struct inet_request_sock *ireq) -{ - return rcu_dereference(ireq->ireq_opt); -} - struct inet_cork { unsigned int flags; __be32 addr; diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c index 6697b180e122..28ad6f187e19 100644 --- a/net/dccp/ipv4.c +++ b/net/dccp/ipv4.c @@ -493,9 +493,11 @@ static int dccp_v4_send_response(const struct sock *sk, struct request_sock *req dh->dccph_checksum = dccp_v4_csum_finish(skb, ireq->ir_loc_addr, ireq->ir_rmt_addr); + rcu_read_lock(); err = ip_build_and_send_pkt(skb, sk, ireq->ir_loc_addr, ireq->ir_rmt_addr, - ireq_opt_deref(ireq)); + rcu_dereference(ireq->ireq_opt)); + rcu_read_unlock(); err = net_xmit_eval(err); } diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index d1cab49393e2..528a6777cda0 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -410,7 +410,8 @@ struct dst_entry *inet_csk_route_req(const struct sock *sk, struct ip_options_rcu *opt; struct rtable *rt; - opt = ireq_opt_deref(ireq); + rcu_read_lock(); + opt = rcu_dereference(ireq->ireq_opt); flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark, RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, @@ -424,11 +425,13 @@ struct dst_entry *inet_csk_route_req(const struct sock *sk, goto no_route; if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway) goto route_err; + rcu_read_unlock(); return &rt->dst; route_err: ip_rt_put(rt); no_route: + rcu_read_unlock(); __IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); return NULL; } diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 16dea67792e0..1ea0c91ba994 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -859,9 +859,11 @@ static int tcp_v4_send_synack(const struct sock *sk, struct dst_entry *dst, if (skb) { __tcp_v4_send_check(skb, ireq->ir_loc_addr, ireq->ir_rmt_addr); + rcu_read_lock(); err = ip_build_and_send_pkt(skb, sk, ireq->ir_loc_addr, ireq->ir_rmt_addr, - ireq_opt_deref(ireq)); + rcu_dereference(ireq->ireq_opt)); + rcu_read_unlock(); err = net_xmit_eval(err); } |