Commit 06dfa963 authored by Elena Reshetova's avatar Elena Reshetova Committed by Ilya Dryomov

libceph: convert ceph_snap_context.nref 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 805692d0
......@@ -14,6 +14,7 @@
#include <linux/wait.h>
#include <linux/writeback.h>
#include <linux/slab.h>
#include <linux/refcount.h>
#include <linux/ceph/types.h>
#include <linux/ceph/messenger.h>
......@@ -161,7 +162,7 @@ struct ceph_client {
* dirtied.
*/
struct ceph_snap_context {
atomic_t nref;
refcount_t nref;
u64 seq;
u32 num_snaps;
u64 snaps[];
......
......@@ -49,7 +49,7 @@ struct ceph_snap_context *ceph_create_snap_context(u32 snap_count,
if (!snapc)
return NULL;
atomic_set(&snapc->nref, 1);
refcount_set(&snapc->nref, 1);
snapc->num_snaps = snap_count;
return snapc;
......@@ -59,7 +59,7 @@ EXPORT_SYMBOL(ceph_create_snap_context);
struct ceph_snap_context *ceph_get_snap_context(struct ceph_snap_context *sc)
{
if (sc)
atomic_inc(&sc->nref);
refcount_inc(&sc->nref);
return sc;
}
EXPORT_SYMBOL(ceph_get_snap_context);
......@@ -68,7 +68,7 @@ void ceph_put_snap_context(struct ceph_snap_context *sc)
{
if (!sc)
return;
if (atomic_dec_and_test(&sc->nref)) {
if (refcount_dec_and_test(&sc->nref)) {
/*printk(" deleting snap_context %p\n", sc);*/
kfree(sc);
}
......
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