net, x25: convert x25_route.refcnt from atomic_t to refcount_t (5f9ccf6f) · Commits · 戴 / test

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:

Elena Reshetova <elena.reshetova@intel.com> Signed-off-by:

Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by:

Kees Cook <keescook@chromium.org> Signed-off-by:

David Windsor <dwindsor@gmail.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

include/net/x25.h

+4 −3

Original line number	Diff line number	Diff line
		@@ -11,6 +11,7 @@
		#define _X25_H
		#include <linux/x25.h>
		#include <linux/slab.h>
		#include <linux/refcount.h>
		#include <net/sock.h>

		#define X25_ADDR_LEN 16
		@@ -129,7 +130,7 @@ struct x25_route {
		struct x25_address address;
		unsigned int sigdigits;
		struct net_device *dev;
		atomic_t refcnt;
		refcount_t refcnt;
		};

		struct x25_neigh {
		@@ -265,12 +266,12 @@ void x25_route_free(void);

		static __inline__ void x25_route_hold(struct x25_route *rt)
		{
		atomic_inc(&rt->refcnt);
		refcount_inc(&rt->refcnt);
		}

		static __inline__ void x25_route_put(struct x25_route *rt)
		{
		if (atomic_dec_and_test(&rt->refcnt))
		if (refcount_dec_and_test(&rt->refcnt))
		kfree(rt);
		}

net/x25/x25_route.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -55,7 +55,7 @@ static int x25_add_route(struct x25_address *address, unsigned int sigdigits,

		rt->sigdigits = sigdigits;
		rt->dev = dev;
		atomic_set(&rt->refcnt, 1);
		refcount_set(&rt->refcnt, 1);

		list_add(&rt->node, &x25_route_list);
		rc = 0;

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