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.reshet...@intel.com>
Signed-off-by: Hans Liljestrand <ishkam...@gmail.com>
Signed-off-by: Kees Cook <keesc...@chromium.org>
Signed-off-by: David Windsor <dwind...@gmail.com>
---
fs/btrfs/delayed-inode.c | 18 +++++++++---------
fs/btrfs/delayed-inode.h | 2 +-
2 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index 7396c36..8ae409b 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -308,7 +308,7 @@ static struct btrfs_delayed_item
*btrfs_alloc_delayed_item(u32 data_len)
item->ins_or_del = 0;
item->bytes_reserved = 0;
item->delayed_node = NULL;
- atomic_set(&item->refs, 1);
+ refcount_set(&item->refs, 1);
}
return item;
}
@@ -483,7 +483,7 @@ static void btrfs_release_delayed_item(struct
btrfs_delayed_item *item)
{
if (item) {
__btrfs_remove_delayed_item(item);
- if (atomic_dec_and_test(&item->refs))
+ if (refcount_dec_and_test(&item->refs))
kfree(item);
}
}
@@ -1600,14 +1600,14 @@ bool btrfs_readdir_get_delayed_items(struct inode
*inode,
mutex_lock(&delayed_node->mutex);
item = __btrfs_first_delayed_insertion_item(delayed_node);
while (item) {
- atomic_inc(&item->refs);
+ refcount_inc(&item->refs);
list_add_tail(&item->readdir_list, ins_list);
item = __btrfs_next_delayed_item(item);
}
item = __btrfs_first_delayed_deletion_item(delayed_node);
while (item) {
- atomic_inc(&item->refs);
+ refcount_inc(&item->refs);
list_add_tail(&item->readdir_list, del_list);
item = __btrfs_next_delayed_item(item);
}
@@ -1634,13 +1634,13 @@ void btrfs_readdir_put_delayed_items(struct inode
*inode,
list_for_each_entry_safe(curr, next, ins_list, readdir_list) {
list_del(&curr->readdir_list);
- if (atomic_dec_and_test(&curr->refs))
+ if (refcount_dec_and_test(&curr->refs))
kfree(curr);
}
list_for_each_entry_safe(curr, next, del_list, readdir_list) {
list_del(&curr->readdir_list);
- if (atomic_dec_and_test(&curr->refs))
+ if (refcount_dec_and_test(&curr->refs))
kfree(curr);
}
@@ -1667,7 +1667,7 @@ int btrfs_should_delete_dir_index(struct list_head
*del_list,
list_del(&curr->readdir_list);
ret = (curr->key.offset == index);
- if (atomic_dec_and_test(&curr->refs))
+ if (refcount_dec_and_test(&curr->refs))
kfree(curr);
if (ret)
@@ -1705,7 +1705,7 @@ int btrfs_readdir_delayed_dir_index(struct dir_context
*ctx,
list_del(&curr->readdir_list);
if (curr->key.offset < ctx->pos) {
- if (atomic_dec_and_test(&curr->refs))
+ if (refcount_dec_and_test(&curr->refs))
kfree(curr);
continue;
}
@@ -1722,7 +1722,7 @@ int btrfs_readdir_delayed_dir_index(struct dir_context
*ctx,
over = !dir_emit(ctx, name, name_len,
location.objectid, d_type);
- if (atomic_dec_and_test(&curr->refs))
+ if (refcount_dec_and_test(&curr->refs))
kfree(curr);
if (over)
diff --git a/fs/btrfs/delayed-inode.h b/fs/btrfs/delayed-inode.h
index d234974..6d4f5a0 100644
--- a/fs/btrfs/delayed-inode.h
+++ b/fs/btrfs/delayed-inode.h
@@ -81,7 +81,7 @@ struct btrfs_delayed_item {
struct list_head readdir_list; /* used for readdir items */
u64 bytes_reserved;
struct btrfs_delayed_node *delayed_node;
- atomic_t refs;
+ refcount_t refs;
int ins_or_del;
u32 data_len;
char data[0];
--
2.7.4
