fuse: convert fuse_conn.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: Miklos Szeredi <mszeredi@redhat.com>
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 6fe6a88..3961c5f 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -608,7 +608,7 @@
memset(fc, 0, sizeof(*fc));
spin_lock_init(&fc->lock);
init_rwsem(&fc->killsb);
- atomic_set(&fc->count, 1);
+ refcount_set(&fc->count, 1);
atomic_set(&fc->dev_count, 1);
init_waitqueue_head(&fc->blocked_waitq);
init_waitqueue_head(&fc->reserved_req_waitq);
@@ -631,7 +631,7 @@
void fuse_conn_put(struct fuse_conn *fc)
{
- if (atomic_dec_and_test(&fc->count)) {
+ if (refcount_dec_and_test(&fc->count)) {
if (fc->destroy_req)
fuse_request_free(fc->destroy_req);
fc->release(fc);
@@ -641,7 +641,7 @@
struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
{
- atomic_inc(&fc->count);
+ refcount_inc(&fc->count);
return fc;
}
EXPORT_SYMBOL_GPL(fuse_conn_get);