btrfs: convert btrfs_transaction.use_count 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: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 5dfb559..902619f 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -18,6 +18,8 @@
#ifndef __BTRFS_TRANSACTION__
#define __BTRFS_TRANSACTION__
+
+#include <linux/refcount.h>
#include "btrfs_inode.h"
#include "delayed-ref.h"
#include "ctree.h"
@@ -49,7 +51,7 @@ struct btrfs_transaction {
* transaction can end
*/
atomic_t num_writers;
- atomic_t use_count;
+ refcount_t use_count;
atomic_t pending_ordered;
unsigned long flags;
