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Commit 87078f26 authored by Reshetova, Elena's avatar Reshetova, Elena Committed by David S. Miller
Browse files

net, ipv6: convert ip6addrlbl_entry.refcnt from atomic_t to refcount_t 



refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: default avatarElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: default avatarHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarDavid Windsor <dwindsor@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d12f3827

net/ipv6/addrlabel.c

+5 −4
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/if_addrlabel.h>

#include <linux/netlink.h>

#include <linux/rtnetlink.h>

#include <linux/refcount.h>



#if 0

#define ADDRLABEL(x...) printk(x)
@@ -36,7 +37,7 @@ struct ip6addrlbl_entry { 
	int addrtype;

	u32 label;

	struct hlist_node list;

	atomic_t refcnt;

	refcount_t refcnt;

	struct rcu_head rcu;

};
@@ -137,12 +138,12 @@ static void ip6addrlbl_free_rcu(struct rcu_head *h) 


static bool ip6addrlbl_hold(struct ip6addrlbl_entry *p)

{

	return atomic_inc_not_zero(&p->refcnt);

	return refcount_inc_not_zero(&p->refcnt);

}



static inline void ip6addrlbl_put(struct ip6addrlbl_entry *p)

{

	if (atomic_dec_and_test(&p->refcnt))

	if (refcount_dec_and_test(&p->refcnt))

		call_rcu(&p->rcu, ip6addrlbl_free_rcu);

}
@@ -236,7 +237,7 @@ static struct ip6addrlbl_entry *ip6addrlbl_alloc(struct net *net, 
	newp->label = label;

	INIT_HLIST_NODE(&newp->list);

	write_pnet(&newp->lbl_net, net);

	atomic_set(&newp->refcnt, 1);

	refcount_set(&newp->refcnt, 1);

	return newp;

}