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| author | Herbert Xu <herbert@gondor.apana.org.au> | 2017-02-11 19:26:46 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-02-17 12:28:35 -0500 |
| commit | 40f9f439706073b4b0a654b3b99e18296b7990b3 (patch) | |
| tree | baa437731befae16bef34595d72e2b64c2e4a97b /net/tipc | |
| parent | 98687f426bb3e93b9dbbfb614ba331192beae482 (diff) | |
| download | linux-40f9f439706073b4b0a654b3b99e18296b7990b3.tar.bz2 | |
tipc: Fix tipc_sk_reinit race conditions
There are two problems with the function tipc_sk_reinit. Firstly
it's doing a manual walk over an rhashtable. This is broken as
an rhashtable can be resized and if you manually walk over it
during a resize then you may miss entries.
Secondly it's missing memory barriers as previously the code used
spinlocks which provide the barriers implicitly.
This patch fixes both problems.
Fixes: 07f6c4bc048a ("tipc: convert tipc reference table to...")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/tipc')
| -rw-r--r-- | net/tipc/net.c | 4 | ||||
| -rw-r--r-- | net/tipc/socket.c | 30 |
2 files changed, 23 insertions, 11 deletions
diff --git a/net/tipc/net.c b/net/tipc/net.c index 28bf4feeb81c..ab8a2d5d1e32 100644 --- a/net/tipc/net.c +++ b/net/tipc/net.c @@ -110,6 +110,10 @@ int tipc_net_start(struct net *net, u32 addr) char addr_string[16]; tn->own_addr = addr; + + /* Ensure that the new address is visible before we reinit. */ + smp_mb(); + tipc_named_reinit(net); tipc_sk_reinit(net); diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 103d1fd058c0..6b09a778cc71 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -430,8 +430,6 @@ static int tipc_sk_create(struct net *net, struct socket *sock, INIT_LIST_HEAD(&tsk->cong_links); msg = &tsk->phdr; tn = net_generic(sock_net(sk), tipc_net_id); - tipc_msg_init(tn->own_addr, msg, TIPC_LOW_IMPORTANCE, TIPC_NAMED_MSG, - NAMED_H_SIZE, 0); /* Finish initializing socket data structures */ sock->ops = ops; @@ -441,6 +439,13 @@ static int tipc_sk_create(struct net *net, struct socket *sock, pr_warn("Socket create failed; port number exhausted\n"); return -EINVAL; } + + /* Ensure tsk is visible before we read own_addr. */ + smp_mb(); + + tipc_msg_init(tn->own_addr, msg, TIPC_LOW_IMPORTANCE, TIPC_NAMED_MSG, + NAMED_H_SIZE, 0); + msg_set_origport(msg, tsk->portid); setup_timer(&sk->sk_timer, tipc_sk_timeout, (unsigned long)tsk); sk->sk_shutdown = 0; @@ -2234,24 +2239,27 @@ static int tipc_sk_withdraw(struct tipc_sock *tsk, uint scope, void tipc_sk_reinit(struct net *net) { struct tipc_net *tn = net_generic(net, tipc_net_id); - const struct bucket_table *tbl; - struct rhash_head *pos; + struct rhashtable_iter iter; struct tipc_sock *tsk; struct tipc_msg *msg; - int i; - rcu_read_lock(); - tbl = rht_dereference_rcu((&tn->sk_rht)->tbl, &tn->sk_rht); - for (i = 0; i < tbl->size; i++) { - rht_for_each_entry_rcu(tsk, pos, tbl, i, node) { + rhashtable_walk_enter(&tn->sk_rht, &iter); + + do { + tsk = ERR_PTR(rhashtable_walk_start(&iter)); + if (tsk) + continue; + + while ((tsk = rhashtable_walk_next(&iter)) && !IS_ERR(tsk)) { spin_lock_bh(&tsk->sk.sk_lock.slock); msg = &tsk->phdr; msg_set_prevnode(msg, tn->own_addr); msg_set_orignode(msg, tn->own_addr); spin_unlock_bh(&tsk->sk.sk_lock.slock); } - } - rcu_read_unlock(); + + rhashtable_walk_stop(&iter); + } while (tsk == ERR_PTR(-EAGAIN)); } static struct tipc_sock *tipc_sk_lookup(struct net *net, u32 portid) |