From 0e1a5ee6577e43e5be55369d398107080b360941 Mon Sep 17 00:00:00 2001 From: Elena Reshetova Date: Fri, 17 Mar 2017 14:10:29 +0200 Subject: [PATCH] libceph: convert ceph_pagelist.refcnt 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 Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor Signed-off-by: Ilya Dryomov --- fs/ceph/mds_client.c | 2 +- include/linux/ceph/pagelist.h | 6 +++--- net/ceph/pagelist.c | 2 +- 3 files changed, 5 insertions(+), 5 deletions(-) diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 074490542b4c..b16f1cf552a8 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -1991,7 +1991,7 @@ static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc, if (req->r_pagelist) { struct ceph_pagelist *pagelist = req->r_pagelist; - atomic_inc(&pagelist->refcnt); + refcount_inc(&pagelist->refcnt); ceph_msg_data_add_pagelist(msg, pagelist); msg->hdr.data_len = cpu_to_le32(pagelist->length); } else { diff --git a/include/linux/ceph/pagelist.h b/include/linux/ceph/pagelist.h index 13d71fe18b0c..75a7db21457d 100644 --- a/include/linux/ceph/pagelist.h +++ b/include/linux/ceph/pagelist.h @@ -2,7 +2,7 @@ #define __FS_CEPH_PAGELIST_H #include -#include +#include #include #include @@ -13,7 +13,7 @@ struct ceph_pagelist { size_t room; struct list_head free_list; size_t num_pages_free; - atomic_t refcnt; + refcount_t refcnt; }; struct ceph_pagelist_cursor { @@ -30,7 +30,7 @@ static inline void ceph_pagelist_init(struct ceph_pagelist *pl) pl->room = 0; INIT_LIST_HEAD(&pl->free_list); pl->num_pages_free = 0; - atomic_set(&pl->refcnt, 1); + refcount_set(&pl->refcnt, 1); } extern void ceph_pagelist_release(struct ceph_pagelist *pl); diff --git a/net/ceph/pagelist.c b/net/ceph/pagelist.c index 6864007e64fc..ce09f73be759 100644 --- a/net/ceph/pagelist.c +++ b/net/ceph/pagelist.c @@ -16,7 +16,7 @@ static void ceph_pagelist_unmap_tail(struct ceph_pagelist *pl) void ceph_pagelist_release(struct ceph_pagelist *pl) { - if (!atomic_dec_and_test(&pl->refcnt)) + if (!refcount_dec_and_test(&pl->refcnt)) return; ceph_pagelist_unmap_tail(pl); while (!list_empty(&pl->head)) { -- 2.20.1