netdev - [PATCH] bonding: add synchronize_net() after netdev_rx_handler

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-next>] [day] [month] [year] [list]

Message-ID: <519C8504.1080906@huawei.com>
Date:	Wed, 22 May 2013 16:42:44 +0800
From:	dingtianhong <dingtianhong@...wei.com>
To:	Jay Vosburgh <fubar@...ibm.com>,
	Andy Gospodarek <andy@...yhouse.net>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Netdev <netdev@...r.kernel.org>, Li Zefan <lizefan@...wei.com>
Subject: [PATCH] bonding: add synchronize_net() after netdev_rx_handler_unregister

commit 00cfec3748 (net: add a synchronize_net() ...) add a synchronize_net()
in netdev_rx_handler_unregister() to guarantee the rx_handler  is NULL when
rx_handler_data is a non NULL in rcu_read_lock().

so the caller should not use netdev_rx_handler_unregister in atomic as it may
schedule and sleep, the commit fcd99434f fix the bug in bond release, but the
problem is no action to guarantee the rx_handler_data is NULL when bond release,
so add synchronize_net() and fix it.

This patch adds more comments to netdev_rx_handler_unregister().

Signed-off-by: Ding Tianhong <dingtianhong@...wei.com>
---
 drivers/net/bonding/bond_main.c | 2 ++
 net/core/dev.c                  | 3 +++
 2 files changed, 5 insertions(+)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index d0aade0..592a603 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2007,6 +2007,8 @@ static int __bond_release_one(struct net_device *bond_dev,
 	 * for this slave anymore.
 	 */
 	netdev_rx_handler_unregister(slave_dev);
+	synchronize_net();
+
 	write_lock_bh(&bond->lock);
 
 	if (!all && !bond->params.fail_over_mac) {
diff --git a/net/core/dev.c b/net/core/dev.c
index fc1e289..9ffeda9 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3344,6 +3344,9 @@ EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
  *	Unregister a receive handler from a device.
  *
  *	The caller must hold the rtnl_mutex.
+ *
+ *	The function should only be called outside the atomic as it
+ *	might sleep and schedule.
  */
 void netdev_rx_handler_unregister(struct net_device *dev)
 {
-- 
1.8.0


--
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