Commit 803ea850 authored by Reshetova, Elena's avatar Reshetova, Elena Committed by David S. Miller
Browse files

net, rds: convert rds_mr.r_refcount 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 b7f02920

net/rds/rdma.c

+5 −5
Original line number Diff line number Diff line
@@ -84,7 +84,7 @@ static struct rds_mr *rds_mr_tree_walk(struct rb_root *root, u64 key, 
	if (insert) {

		rb_link_node(&insert->r_rb_node, parent, p);

		rb_insert_color(&insert->r_rb_node, root);

		atomic_inc(&insert->r_refcount);

		refcount_inc(&insert->r_refcount);

	}

	return NULL;

}
@@ -99,7 +99,7 @@ static void rds_destroy_mr(struct rds_mr *mr) 
	unsigned long flags;



	rdsdebug("RDS: destroy mr key is %x refcnt %u\n",

			mr->r_key, atomic_read(&mr->r_refcount));

			mr->r_key, refcount_read(&mr->r_refcount));



	if (test_and_set_bit(RDS_MR_DEAD, &mr->r_state))

		return;
@@ -223,7 +223,7 @@ static int __rds_rdma_map(struct rds_sock *rs, struct rds_get_mr_args *args, 
		goto out;

	}



	atomic_set(&mr->r_refcount, 1);

	refcount_set(&mr->r_refcount, 1);

	RB_CLEAR_NODE(&mr->r_rb_node);

	mr->r_trans = rs->rs_transport;

	mr->r_sock = rs;
@@ -307,7 +307,7 @@ static int __rds_rdma_map(struct rds_sock *rs, struct rds_get_mr_args *args, 


	rdsdebug("RDS: get_mr key is %x\n", mr->r_key);

	if (mr_ret) {

		atomic_inc(&mr->r_refcount);

		refcount_inc(&mr->r_refcount);

		*mr_ret = mr;

	}
@@ -756,7 +756,7 @@ int rds_cmsg_rdma_dest(struct rds_sock *rs, struct rds_message *rm, 
	if (!mr)

		err = -EINVAL;	/* invalid r_key */

	else

		atomic_inc(&mr->r_refcount);

		refcount_inc(&mr->r_refcount);

	spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);



	if (mr) {

net/rds/rds.h

+2 −2
Original line number Diff line number Diff line
@@ -277,7 +277,7 @@ struct rds_incoming { 


struct rds_mr {

	struct rb_node		r_rb_node;

	atomic_t		r_refcount;

	refcount_t		r_refcount;

	u32			r_key;



	/* A copy of the creation flags */
@@ -857,7 +857,7 @@ int rds_cmsg_atomic(struct rds_sock *rs, struct rds_message *rm, 
void __rds_put_mr_final(struct rds_mr *mr);

static inline void rds_mr_put(struct rds_mr *mr)

{

	if (atomic_dec_and_test(&mr->r_refcount))

	if (refcount_dec_and_test(&mr->r_refcount))

		__rds_put_mr_final(mr);

}

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