Message ID | 1539377215-29145-1-git-send-email-jon.maloy@ericsson.com |
---|---|
State | Accepted, archived |
Delegated to: | David Miller |
Headers | show |
Series | [net,1/1] tipc: fix unsafe rcu locking when accessing publication list | expand |
From: Jon Maloy <jon.maloy@ericsson.com> Date: Fri, 12 Oct 2018 22:46:55 +0200 > From: Tung Nguyen <tung.q.nguyen@dektech.com.au> > > The binding table's 'cluster_scope' list is rcu protected to handle > races between threads changing the list and those traversing the list at > the same moment. We have now found that the function named_distribute() > uses the regular list_for_each() macro to traverse the said list. > Likewise, the function tipc_named_withdraw() is removing items from the > same list using the regular list_del() call. When these two functions > execute in parallel we see occasional crashes. > > This commit fixes this by adding the missing _rcu() suffixes. > > Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au> > Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Applied and queued up for -stable.
diff --git a/net/tipc/name_distr.c b/net/tipc/name_distr.c index 51b4b96..3cfeb9d 100644 --- a/net/tipc/name_distr.c +++ b/net/tipc/name_distr.c @@ -115,7 +115,7 @@ struct sk_buff *tipc_named_withdraw(struct net *net, struct publication *publ) struct sk_buff *buf; struct distr_item *item; - list_del(&publ->binding_node); + list_del_rcu(&publ->binding_node); if (publ->scope == TIPC_NODE_SCOPE) return NULL; @@ -147,7 +147,7 @@ static void named_distribute(struct net *net, struct sk_buff_head *list, ITEM_SIZE) * ITEM_SIZE; u32 msg_rem = msg_dsz; - list_for_each_entry(publ, pls, binding_node) { + list_for_each_entry_rcu(publ, pls, binding_node) { /* Prepare next buffer: */ if (!skb) { skb = named_prepare_buf(net, PUBLICATION, msg_rem,