ceph: convert ceph_cap_snap.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: 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: Ilya Dryomov <idryomov@gmail.com>
diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c
index 8f8b41c..dab5d67 100644
--- a/fs/ceph/snap.c
+++ b/fs/ceph/snap.c
@@ -519,7 +519,7 @@ void ceph_queue_cap_snap(struct ceph_inode_info *ci)
capsnap->need_flush ? "" : "no_flush");
ihold(inode);
- atomic_set(&capsnap->nref, 1);
+ refcount_set(&capsnap->nref, 1);
INIT_LIST_HEAD(&capsnap->ci_item);
capsnap->follows = old_snapc->seq;