[05/23] net, ceph: convert ceph_osd.o_ref from atomic_t to refcount_t
diff mbox

Message ID 1489752646-8749-6-git-send-email-elena.reshetova@intel.com
State New
Headers show

Commit Message

Reshetova, Elena March 17, 2017, 12:10 p.m. UTC
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>
---
 include/linux/ceph/osd_client.h |  3 ++-
 net/ceph/osd_client.c           | 16 ++++++++--------
 2 files changed, 10 insertions(+), 9 deletions(-)

Comments

Ilya Dryomov March 24, 2017, 1:49 p.m. UTC | #1
On Fri, Mar 17, 2017 at 1:10 PM, Elena Reshetova
<elena.reshetova@intel.com> wrote:
> 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>
> ---
>  include/linux/ceph/osd_client.h |  3 ++-
>  net/ceph/osd_client.c           | 16 ++++++++--------
>  2 files changed, 10 insertions(+), 9 deletions(-)
>
> diff --git a/include/linux/ceph/osd_client.h b/include/linux/ceph/osd_client.h
> index 2ea0c28..5ce0cd6 100644
> --- a/include/linux/ceph/osd_client.h
> +++ b/include/linux/ceph/osd_client.h
> @@ -5,6 +5,7 @@
>  #include <linux/kref.h>
>  #include <linux/mempool.h>
>  #include <linux/rbtree.h>
> +#include <linux/refcount.h>
>
>  #include <linux/ceph/types.h>
>  #include <linux/ceph/osdmap.h>
> @@ -27,7 +28,7 @@ typedef void (*ceph_osdc_callback_t)(struct ceph_osd_request *);
>
>  /* a given osd we're communicating with */
>  struct ceph_osd {
> -       atomic_t o_ref;
> +       refcount_t o_ref;
>         struct ceph_osd_client *o_osdc;
>         int o_osd;
>         int o_incarnation;
> diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
> index b65bbf9..99a51f0 100644
> --- a/net/ceph/osd_client.c
> +++ b/net/ceph/osd_client.c
> @@ -1005,7 +1005,7 @@ static bool osd_registered(struct ceph_osd *osd)
>   */
>  static void osd_init(struct ceph_osd *osd)
>  {
> -       atomic_set(&osd->o_ref, 1);
> +       refcount_set(&osd->o_ref, 1);
>         RB_CLEAR_NODE(&osd->o_node);
>         osd->o_requests = RB_ROOT;
>         osd->o_linger_requests = RB_ROOT;
> @@ -1050,9 +1050,9 @@ static struct ceph_osd *create_osd(struct ceph_osd_client *osdc, int onum)
>
>  static struct ceph_osd *get_osd(struct ceph_osd *osd)
>  {
> -       if (atomic_inc_not_zero(&osd->o_ref)) {
> -               dout("get_osd %p %d -> %d\n", osd, atomic_read(&osd->o_ref)-1,
> -                    atomic_read(&osd->o_ref));
> +       if (refcount_inc_not_zero(&osd->o_ref)) {
> +               dout("get_osd %p %d -> %d\n", osd, refcount_read(&osd->o_ref)-1,
> +                    refcount_read(&osd->o_ref));
>                 return osd;
>         } else {
>                 dout("get_osd %p FAIL\n", osd);
> @@ -1062,9 +1062,9 @@ static struct ceph_osd *get_osd(struct ceph_osd *osd)
>
>  static void put_osd(struct ceph_osd *osd)
>  {
> -       dout("put_osd %p %d -> %d\n", osd, atomic_read(&osd->o_ref),
> -            atomic_read(&osd->o_ref) - 1);
> -       if (atomic_dec_and_test(&osd->o_ref)) {
> +       dout("put_osd %p %d -> %d\n", osd, refcount_read(&osd->o_ref),
> +            refcount_read(&osd->o_ref) - 1);
> +       if (refcount_dec_and_test(&osd->o_ref)) {
>                 osd_cleanup(osd);
>                 kfree(osd);
>         }
> @@ -4092,7 +4092,7 @@ void ceph_osdc_stop(struct ceph_osd_client *osdc)
>                 close_osd(osd);
>         }
>         up_write(&osdc->lock);
> -       WARN_ON(atomic_read(&osdc->homeless_osd.o_ref) != 1);
> +       WARN_ON(refcount_read(&osdc->homeless_osd.o_ref) != 1);
>         osd_cleanup(&osdc->homeless_osd);
>
>         WARN_ON(!list_empty(&osdc->osd_lru));

Applied.

Thanks,

                Ilya
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Patch
diff mbox

diff --git a/include/linux/ceph/osd_client.h b/include/linux/ceph/osd_client.h
index 2ea0c28..5ce0cd6 100644
--- a/include/linux/ceph/osd_client.h
+++ b/include/linux/ceph/osd_client.h
@@ -5,6 +5,7 @@ 
 #include <linux/kref.h>
 #include <linux/mempool.h>
 #include <linux/rbtree.h>
+#include <linux/refcount.h>
 
 #include <linux/ceph/types.h>
 #include <linux/ceph/osdmap.h>
@@ -27,7 +28,7 @@  typedef void (*ceph_osdc_callback_t)(struct ceph_osd_request *);
 
 /* a given osd we're communicating with */
 struct ceph_osd {
-	atomic_t o_ref;
+	refcount_t o_ref;
 	struct ceph_osd_client *o_osdc;
 	int o_osd;
 	int o_incarnation;
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index b65bbf9..99a51f0 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -1005,7 +1005,7 @@  static bool osd_registered(struct ceph_osd *osd)
  */
 static void osd_init(struct ceph_osd *osd)
 {
-	atomic_set(&osd->o_ref, 1);
+	refcount_set(&osd->o_ref, 1);
 	RB_CLEAR_NODE(&osd->o_node);
 	osd->o_requests = RB_ROOT;
 	osd->o_linger_requests = RB_ROOT;
@@ -1050,9 +1050,9 @@  static struct ceph_osd *create_osd(struct ceph_osd_client *osdc, int onum)
 
 static struct ceph_osd *get_osd(struct ceph_osd *osd)
 {
-	if (atomic_inc_not_zero(&osd->o_ref)) {
-		dout("get_osd %p %d -> %d\n", osd, atomic_read(&osd->o_ref)-1,
-		     atomic_read(&osd->o_ref));
+	if (refcount_inc_not_zero(&osd->o_ref)) {
+		dout("get_osd %p %d -> %d\n", osd, refcount_read(&osd->o_ref)-1,
+		     refcount_read(&osd->o_ref));
 		return osd;
 	} else {
 		dout("get_osd %p FAIL\n", osd);
@@ -1062,9 +1062,9 @@  static struct ceph_osd *get_osd(struct ceph_osd *osd)
 
 static void put_osd(struct ceph_osd *osd)
 {
-	dout("put_osd %p %d -> %d\n", osd, atomic_read(&osd->o_ref),
-	     atomic_read(&osd->o_ref) - 1);
-	if (atomic_dec_and_test(&osd->o_ref)) {
+	dout("put_osd %p %d -> %d\n", osd, refcount_read(&osd->o_ref),
+	     refcount_read(&osd->o_ref) - 1);
+	if (refcount_dec_and_test(&osd->o_ref)) {
 		osd_cleanup(osd);
 		kfree(osd);
 	}
@@ -4092,7 +4092,7 @@  void ceph_osdc_stop(struct ceph_osd_client *osdc)
 		close_osd(osd);
 	}
 	up_write(&osdc->lock);
-	WARN_ON(atomic_read(&osdc->homeless_osd.o_ref) != 1);
+	WARN_ON(refcount_read(&osdc->homeless_osd.o_ref) != 1);
 	osd_cleanup(&osdc->homeless_osd);
 
 	WARN_ON(!list_empty(&osdc->osd_lru));