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>
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 *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 @@
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,
