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authorTung Nguyen <tung.q.nguyen@dektech.com.au>2018-10-12 22:46:55 +0200
committerDavid S. Miller <davem@davemloft.net>2018-10-15 22:33:27 -0700
commitd3092b2efca1cd1d492d0b08499a2066c5ca8cec (patch)
tree9840478f060772c97d0379312224889e5953e94e /net
parent7ec8dc96e1cb45693f28f1287802ef6f2888dae0 (diff)
downloadlinux-d3092b2efca1cd1d492d0b08499a2066c5ca8cec.tar.gz
tipc: fix unsafe rcu locking when accessing publication list
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/tipc/name_distr.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/tipc/name_distr.c b/net/tipc/name_distr.c
index 51b4b96f89db..3cfeb9df64b0 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,