Commit 02113a0f authored by Elena Reshetova's avatar Elena Reshetova Committed by Ilya Dryomov
Browse files

libceph: convert ceph_osd.o_ref 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 avatarIlya Dryomov <idryomov@gmail.com>
parent 06dfa963

include/linux/ceph/osd_client.h

+2 −1
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
#include <linux/kref.h>

#include <linux/mempool.h>

#include <linux/rbtree.h>

#include <linux/refcount.h>



#include <linux/ceph/types.h>

#include <linux/ceph/osdmap.h>
@@ -27,7 +28,7 @@ typedef void (*ceph_osdc_callback_t)(struct ceph_osd_request *); 


/* a given osd we're communicating with */

struct ceph_osd {

	atomic_t o_ref;

	refcount_t o_ref;

	struct ceph_osd_client *o_osdc;

	int o_osd;

	int o_incarnation;

net/ceph/osd_client.c

+8 −8
Original line number Diff line number Diff line
@@ -1005,7 +1005,7 @@ static bool osd_registered(struct ceph_osd *osd) 
 */

static void osd_init(struct ceph_osd *osd)

{

	atomic_set(&osd->o_ref, 1);

	refcount_set(&osd->o_ref, 1);

	RB_CLEAR_NODE(&osd->o_node);

	osd->o_requests = RB_ROOT;

	osd->o_linger_requests = RB_ROOT;
@@ -1050,9 +1050,9 @@ static struct ceph_osd *create_osd(struct ceph_osd_client *osdc, int onum) 


static struct ceph_osd *get_osd(struct ceph_osd *osd)

{

	if (atomic_inc_not_zero(&osd->o_ref)) {

		dout("get_osd %p %d -> %d\n", osd, atomic_read(&osd->o_ref)-1,

		     atomic_read(&osd->o_ref));

	if (refcount_inc_not_zero(&osd->o_ref)) {

		dout("get_osd %p %d -> %d\n", osd, refcount_read(&osd->o_ref)-1,

		     refcount_read(&osd->o_ref));

		return osd;

	} else {

		dout("get_osd %p FAIL\n", osd);
@@ -1062,9 +1062,9 @@ static struct ceph_osd *get_osd(struct ceph_osd *osd) 


static void put_osd(struct ceph_osd *osd)

{

	dout("put_osd %p %d -> %d\n", osd, atomic_read(&osd->o_ref),

	     atomic_read(&osd->o_ref) - 1);

	if (atomic_dec_and_test(&osd->o_ref)) {

	dout("put_osd %p %d -> %d\n", osd, refcount_read(&osd->o_ref),

	     refcount_read(&osd->o_ref) - 1);

	if (refcount_dec_and_test(&osd->o_ref)) {

		osd_cleanup(osd);

		kfree(osd);

	}
@@ -4126,7 +4126,7 @@ void ceph_osdc_stop(struct ceph_osd_client *osdc) 
		close_osd(osd);

	}

	up_write(&osdc->lock);

	WARN_ON(atomic_read(&osdc->homeless_osd.o_ref) != 1);

	WARN_ON(refcount_read(&osdc->homeless_osd.o_ref) != 1);

	osd_cleanup(&osdc->homeless_osd);



	WARN_ON(!list_empty(&osdc->osd_lru));

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