net, netrom: convert nr_node.refcount from atomic_t to refcount_t (156be7ed) · 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/netrom.h

+3 −3

Original line number	Diff line number	Diff line
		@@ -110,7 +110,7 @@ struct nr_node {
		unsigned char which;
		unsigned char count;
		struct nr_route routes[3];
		atomic_t refcount;
		refcount_t refcount;
		spinlock_t node_lock;
		};

		@@ -119,11 +119,11 @@ struct nr_node {
		*********************************************************************/

		#define nr_node_hold(__nr_node) \
		atomic_inc(&((__nr_node)->refcount))
		refcount_inc(&((__nr_node)->refcount))

		static __inline__ void nr_node_put(struct nr_node *nr_node)
		{
		if (atomic_dec_and_test(&nr_node->refcount)) {
		if (refcount_dec_and_test(&nr_node->refcount)) {
		kfree(nr_node);
		}
		}

net/netrom/nr_route.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -184,7 +184,7 @@ static int __must_check nr_add_node(ax25_address nr, const char mnemonic,

		nr_node->which = 0;
		nr_node->count = 1;
		atomic_set(&nr_node->refcount, 1);
		refcount_set(&nr_node->refcount, 1);
		spin_lock_init(&nr_node->node_lock);

		nr_node->routes[0].quality = quality;

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