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/fuse/dev.c | 10 +++++-----
fs/fuse/fuse_i.h | 2 +-
2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index f117926..3e67205 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -44,7 +44,7 @@ static void fuse_request_init(struct fuse_req *req, struct
page **pages,
INIT_LIST_HEAD(&req->list);
INIT_LIST_HEAD(&req->intr_entry);
init_waitqueue_head(&req->waitq);
- atomic_set(&req->count, 1);
+ refcount_set(&req->count, 1);
req->pages = pages;
req->page_descs = page_descs;
req->max_pages = npages;
@@ -101,14 +101,14 @@ void fuse_request_free(struct fuse_req *req)
void __fuse_get_request(struct fuse_req *req)
{
- atomic_inc(&req->count);
+ refcount_inc(&req->count);
}
/* Must be called with > 1 refcount */
static void __fuse_put_request(struct fuse_req *req)
{
- BUG_ON(atomic_read(&req->count) < 2);
- atomic_dec(&req->count);
+ BUG_ON(refcount_read(&req->count) < 2);
+ refcount_dec(&req->count);
}
static void fuse_req_init_context(struct fuse_req *req)
@@ -263,7 +263,7 @@ struct fuse_req *fuse_get_req_nofail_nopages(struct
fuse_conn *fc,
void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
{
- if (atomic_dec_and_test(&req->count)) {
+ if (refcount_dec_and_test(&req->count)) {
if (test_bit(FR_BACKGROUND, &req->flags)) {
/*
* We get here in the unlikely case that a background
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 1d6d67e..9d43740 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -307,7 +307,7 @@ struct fuse_req {
struct list_head intr_entry;
/** refcount */
- atomic_t count;
+ refcount_t count;
/** Unique ID for the interrupt request */
u64 intr_unique;
--
2.7.4
