[PATCH 4/5] fs, xfs: convert xfs_cui_log_item.cui_refcount from atomic_t to refcount_t
From: Elena Reshetova
Date: Wed Mar 08 2017 - 09:34:24 EST
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@xxxxxxxxx>
Signed-off-by: Hans Liljestrand <ishkamiel@xxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: David Windsor <dwindsor@xxxxxxxxx>
---
fs/xfs/xfs_refcount_item.c | 4 ++--
fs/xfs/xfs_refcount_item.h | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/xfs/xfs_refcount_item.c b/fs/xfs/xfs_refcount_item.c
index 6e4c744..61bc570 100644
--- a/fs/xfs/xfs_refcount_item.c
+++ b/fs/xfs/xfs_refcount_item.c
@@ -205,7 +205,7 @@ xfs_cui_init(
cuip->cui_format.cui_nextents = nextents;
cuip->cui_format.cui_id = (uintptr_t)(void *)cuip;
atomic_set(&cuip->cui_next_extent, 0);
- atomic_set(&cuip->cui_refcount, 2);
+ refcount_set(&cuip->cui_refcount, 2);
return cuip;
}
@@ -221,7 +221,7 @@ void
xfs_cui_release(
struct xfs_cui_log_item *cuip)
{
- if (atomic_dec_and_test(&cuip->cui_refcount)) {
+ if (refcount_dec_and_test(&cuip->cui_refcount)) {
xfs_trans_ail_remove(&cuip->cui_item, SHUTDOWN_LOG_IO_ERROR);
xfs_cui_item_free(cuip);
}
diff --git a/fs/xfs/xfs_refcount_item.h b/fs/xfs/xfs_refcount_item.h
index 5b74ddd..abc0377 100644
--- a/fs/xfs/xfs_refcount_item.h
+++ b/fs/xfs/xfs_refcount_item.h
@@ -63,7 +63,7 @@ struct kmem_zone;
*/
struct xfs_cui_log_item {
struct xfs_log_item cui_item;
- atomic_t cui_refcount;
+ refcount_t cui_refcount;
atomic_t cui_next_extent;
unsigned long cui_flags; /* misc flags */
struct xfs_cui_log_format cui_format;
--
2.7.4