Commit-ID: b02b69c8a403859ec72090742727e853d606a325
Gitweb: http://git.kernel.org/tip/b02b69c8a403859ec72090742727e853d606a325
Author: Allan Stephens <allan.stephens@xxxxxxxxxxxxx>
AuthorDate: Tue, 17 Aug 2010 11:00:07 +0000
Committer: David S. Miller <davem@xxxxxxxxxxxxx>
CommitDate: Tue, 17 Aug 2010 17:31:53 -0700
tipc: Check for disabled bearer when processing incoming messages
Add a check to tipc_recv_msg() to ensure it discards messages
arriving on a newly disabled bearer. This is needed to deal with a
race condition that can arise if the bearer is in the midst of being
disabled when it receives a message. Performing the check after
tipc_net_lock has been taken ensures that TIPC's bearers are in a
stable state while the message is being processed.
Signed-off-by: Allan Stephens <allan.stephens@xxxxxxxxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
---
net/tipc/link.c | 14 ++++++++++++++
1 files changed, 14 insertions(+), 0 deletions(-)
diff --git a/net/tipc/link.c b/net/tipc/link.c
index a3616b9..9d18c9b 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1802,6 +1802,15 @@ static int link_recv_buf_validate(struct sk_buff *buf)
return pskb_may_pull(buf, hdr_size);
}
+/**
+ * tipc_recv_msg - process TIPC messages arriving from off-node
+ * @head: pointer to message buffer chain
+ * @tb_ptr: pointer to bearer message arrived on
+ *
+ * Invoked with no locks held. Bearer pointer must point to a valid bearer
+ * structure (i.e. cannot be NULL), but bearer can be inactive.
+ */
+
void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *tb_ptr)
{
read_lock_bh(&tipc_net_lock);
@@ -1819,6 +1828,11 @@ void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *tb_ptr)
head = head->next;
+ /* Ensure bearer is still enabled */
+
+ if (unlikely(!b_ptr->active))
+ goto cont;
+
/* Ensure message is well-formed */
if (unlikely(!link_recv_buf_validate(buf)))
--
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