Commit 872ac785 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

ipv4: ip_tunnel: spread netdev_lockdep_set_classes() 



Inspired by yet another syzbot report.

IPv6 tunnels call netdev_lockdep_set_classes() for each tunnel type,
while IPv4 currently centralizes netdev_lockdep_set_classes() call from
ip_tunnel_init().

Make ip_tunnel_init() a macro, so that we have different lockdep
classes per tunnel type.

Fixes: 0bef5120 ("net: add netdev_lockdep_set_classes() to virtual drivers")
Reported-by: default avatar <syzbot+1240b33467289f5ab50b@syzkaller.appspotmail.com>
Closes: https://lore.kernel.org/netdev/695d439f.050a0220.1c677c.0347.GAE@google.com/T/#u


Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260106172426.1760721-1-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 56d0aea0

include/net/ip_tunnels.h

+12 −1
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <net/rtnetlink.h>

#include <net/lwtunnel.h>

#include <net/dst_cache.h>

#include <net/netdev_lock.h>



#if IS_ENABLED(CONFIG_IPV6)

#include <net/ipv6.h>
@@ -372,7 +373,17 @@ static inline void ip_tunnel_init_flow(struct flowi4 *fl4, 
	fl4->flowi4_flags = flow_flags;

}



int ip_tunnel_init(struct net_device *dev);

int __ip_tunnel_init(struct net_device *dev);

#define ip_tunnel_init(DEV)			\

({						\

	struct net_device *__dev = (DEV);	\

	int __res = __ip_tunnel_init(__dev);	\

						\

	if (!__res)				\

		netdev_lockdep_set_classes(__dev);\

	__res;					\

})



void ip_tunnel_uninit(struct net_device *dev);

void  ip_tunnel_dellink(struct net_device *dev, struct list_head *head);

struct net *ip_tunnel_get_link_net(const struct net_device *dev);

net/ipv4/ip_tunnel.c

+2 −3
Original line number Diff line number Diff line
@@ -1281,7 +1281,7 @@ int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[], 
}

EXPORT_SYMBOL_GPL(ip_tunnel_changelink);



int ip_tunnel_init(struct net_device *dev)

int __ip_tunnel_init(struct net_device *dev)

{

	struct ip_tunnel *tunnel = netdev_priv(dev);

	struct iphdr *iph = &tunnel->parms.iph;
@@ -1308,10 +1308,9 @@ int ip_tunnel_init(struct net_device *dev) 


	if (tunnel->collect_md)

		netif_keep_dst(dev);

	netdev_lockdep_set_classes(dev);

	return 0;

}

EXPORT_SYMBOL_GPL(ip_tunnel_init);

EXPORT_SYMBOL_GPL(__ip_tunnel_init);



void ip_tunnel_uninit(struct net_device *dev)

{