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Commit 768b9549 authored by Veaceslav Falico's avatar Veaceslav Falico Committed by David S. Miller
Browse files

bonding: fix __get_first_agg RCU usage 



Currently, the RCU read lock usage is just wrong - it gets the slave struct
under RCU and continues to use it when RCU lock is released.

However, it's still safe to do this cause we didn't need the
rcu_read_lock() initially - all of the __get_first_agg() callers are either
holding RCU read lock or the RTNL lock, so that we can't sync while in it.

Fixes: be79bd04 ("bonding: add RCU for bond_3ad_state_machine_handler()")
CC: dingtianhong@huawei.com
CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: default avatarVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c1bc9644

drivers/net/bonding/bond_3ad.c

+4 −1
Original line number Diff line number Diff line
@@ -143,11 +143,13 @@ static inline struct bonding *__get_bond_by_port(struct port *port) 
 *

 * Return the aggregator of the first slave in @bond, or %NULL if it can't be

 * found.

 * The caller must hold RCU or RTNL lock.

 */

static inline struct aggregator *__get_first_agg(struct port *port)

{

	struct bonding *bond = __get_bond_by_port(port);

	struct slave *first_slave;

	struct aggregator *agg;



	/* If there's no bond for this port, or bond has no slaves */

	if (bond == NULL)
@@ -155,9 +157,10 @@ static inline struct aggregator *__get_first_agg(struct port *port) 


	rcu_read_lock();

	first_slave = bond_first_slave_rcu(bond);

	agg = first_slave ? &(SLAVE_AD_INFO(first_slave).aggregator) : NULL;

	rcu_read_unlock();



	return first_slave ? &(SLAVE_AD_INFO(first_slave).aggregator) : NULL;

	return agg;

}



/**