netdev - [PATCH net-next 05/14] tipc: Check for disabled bearer when processing incoming messages

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1282078816-11844-6-git-send-email-paul.gortmaker@windriver.com>
Date:	Tue, 17 Aug 2010 17:00:07 -0400
From:	Paul Gortmaker <paul.gortmaker@...driver.com>
To:	davem@...emloft.net
Cc:	netdev@...r.kernel.org, allan.stephens@...driver.com
Subject: [PATCH net-next 05/14] tipc: Check for disabled bearer when processing incoming messages

From: Allan Stephens <allan.stephens@...driver.com>

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@...driver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@...driver.com>
---
 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)))
-- 
1.7.2.1

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html