Commit d6ca1995 authored by Zeeshan Ahmad's avatar Zeeshan Ahmad Committed by Jakub Kicinski
Browse files

net: core: failover: enforce mandatory ops and clean up redundant checks 



The failover framework requires 'ops' to be functional. Currently,
failover_register() allows an instance to be registered with NULL
ops, which leads to inconsistent NULL checks and potential NULL
pointer dereferences in the slave registration paths.

Harden the entry point by requiring non-NULL ops in
failover_register(). This ensures the 'fops' pointer is guaranteed
to be valid for any successfully registered failover instance.
Consequently, remove the now redundant NULL checks for 'fops'
throughout the module to simplify the logic.

Signed-off-by: default avatarZeeshan Ahmad <zeeshanahmad022019@gmail.com>
Link: https://patch.msgid.link/20260302064317.9964-1-zeeshanahmad022019@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent dfa77c0d

net/core/failover.c

+7 −7
Original line number Diff line number Diff line
@@ -59,7 +59,7 @@ static int failover_slave_register(struct net_device *slave_dev) 
	if (!failover_dev)

		goto done;



	if (fops && fops->slave_pre_register &&

	if (fops->slave_pre_register &&

	    fops->slave_pre_register(slave_dev, failover_dev))

		goto done;
@@ -82,7 +82,7 @@ static int failover_slave_register(struct net_device *slave_dev) 


	slave_dev->priv_flags |= (IFF_FAILOVER_SLAVE | IFF_NO_ADDRCONF);



	if (fops && fops->slave_register &&

	if (fops->slave_register &&

	    !fops->slave_register(slave_dev, failover_dev))

		return NOTIFY_OK;
@@ -115,7 +115,7 @@ int failover_slave_unregister(struct net_device *slave_dev) 
	if (!failover_dev)

		goto done;



	if (fops && fops->slave_pre_unregister &&

	if (fops->slave_pre_unregister &&

	    fops->slave_pre_unregister(slave_dev, failover_dev))

		goto done;
@@ -123,7 +123,7 @@ int failover_slave_unregister(struct net_device *slave_dev) 
	netdev_upper_dev_unlink(slave_dev, failover_dev);

	slave_dev->priv_flags &= ~(IFF_FAILOVER_SLAVE | IFF_NO_ADDRCONF);



	if (fops && fops->slave_unregister &&

	if (fops->slave_unregister &&

	    !fops->slave_unregister(slave_dev, failover_dev))

		return NOTIFY_OK;
@@ -149,7 +149,7 @@ static int failover_slave_link_change(struct net_device *slave_dev) 
	if (!netif_running(failover_dev))

		goto done;



	if (fops && fops->slave_link_change &&

	if (fops->slave_link_change &&

	    !fops->slave_link_change(slave_dev, failover_dev))

		return NOTIFY_OK;
@@ -174,7 +174,7 @@ static int failover_slave_name_change(struct net_device *slave_dev) 
	if (!netif_running(failover_dev))

		goto done;



	if (fops && fops->slave_name_change &&

	if (fops->slave_name_change &&

	    !fops->slave_name_change(slave_dev, failover_dev))

		return NOTIFY_OK;
@@ -244,7 +244,7 @@ struct failover *failover_register(struct net_device *dev, 
{

	struct failover *failover;



	if (dev->type != ARPHRD_ETHER)

	if (dev->type != ARPHRD_ETHER || !ops)

		return ERR_PTR(-EINVAL);



	failover = kzalloc_obj(*failover);