Commit b7f02920 authored by Reshetova, Elena's avatar Reshetova, Elena Committed by David S. Miller
Browse files

net, rds: convert rds_incoming.i_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 50d61ff7

net/rds/rds.h

+2 −1
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <linux/mutex.h>

#include <linux/rds.h>

#include <linux/rhashtable.h>

#include <linux/refcount.h>



#include "info.h"
@@ -261,7 +262,7 @@ struct rds_ext_header_rdma_dest { 
#define	RDS_MSG_RX_CMSG		3



struct rds_incoming {

	atomic_t		i_refcount;

	refcount_t		i_refcount;

	struct list_head	i_item;

	struct rds_connection	*i_conn;

	struct rds_conn_path	*i_conn_path;

net/rds/recv.c

+6 −6
Original line number Diff line number Diff line
@@ -45,7 +45,7 @@ void rds_inc_init(struct rds_incoming *inc, struct rds_connection *conn, 
{

	int i;



	atomic_set(&inc->i_refcount, 1);

	refcount_set(&inc->i_refcount, 1);

	INIT_LIST_HEAD(&inc->i_item);

	inc->i_conn = conn;

	inc->i_saddr = saddr;
@@ -61,7 +61,7 @@ EXPORT_SYMBOL_GPL(rds_inc_init); 
void rds_inc_path_init(struct rds_incoming *inc, struct rds_conn_path *cp,

		       __be32 saddr)

{

	atomic_set(&inc->i_refcount, 1);

	refcount_set(&inc->i_refcount, 1);

	INIT_LIST_HEAD(&inc->i_item);

	inc->i_conn = cp->cp_conn;

	inc->i_conn_path = cp;
@@ -74,14 +74,14 @@ EXPORT_SYMBOL_GPL(rds_inc_path_init); 


static void rds_inc_addref(struct rds_incoming *inc)

{

	rdsdebug("addref inc %p ref %d\n", inc, atomic_read(&inc->i_refcount));

	atomic_inc(&inc->i_refcount);

	rdsdebug("addref inc %p ref %d\n", inc, refcount_read(&inc->i_refcount));

	refcount_inc(&inc->i_refcount);

}



void rds_inc_put(struct rds_incoming *inc)

{

	rdsdebug("put inc %p ref %d\n", inc, atomic_read(&inc->i_refcount));

	if (atomic_dec_and_test(&inc->i_refcount)) {

	rdsdebug("put inc %p ref %d\n", inc, refcount_read(&inc->i_refcount));

	if (refcount_dec_and_test(&inc->i_refcount)) {

		BUG_ON(!list_empty(&inc->i_item));



		inc->i_conn->c_trans->inc_free(inc);

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