From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Elena Reshetova To: gregkh@linuxfoundation.org Cc: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, netdev@vger.kernel.org, linux1394-devel@lists.sourceforge.net, linux-bcache@vger.kernel.org, linux-raid@vger.kernel.org, linux-media@vger.kernel.org, devel@linuxdriverproject.org, linux-pci@vger.kernel.org, linux-s390@vger.kernel.org, fcoe-devel@open-fcoe.org, linux-scsi@vger.kernel.org, open-iscsi@googlegroups.com, devel@driverdev.osuosl.org, target-devel@vger.kernel.org, linux-serial@vger.kernel.org, linux-usb@vger.kernel.org, peterz@infradead.org, Elena Reshetova , Hans Liljestrand , Kees Cook , David Windsor Subject: [PATCH 13/29] drivers, media: convert vb2_vmarea_handler.refcount from atomic_t to refcount_t Date: Mon, 6 Mar 2017 16:21:00 +0200 Message-Id: <1488810076-3754-14-git-send-email-elena.reshetova@intel.com> In-Reply-To: <1488810076-3754-1-git-send-email-elena.reshetova@intel.com> References: <1488810076-3754-1-git-send-email-elena.reshetova@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 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 --- drivers/media/v4l2-core/videobuf2-memops.c | 6 +++--- include/media/videobuf2-memops.h | 3 ++- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/media/v4l2-core/videobuf2-memops.c b/drivers/media/v4l2-core/videobuf2-memops.c index 1cd322e..4bb8424 100644 --- a/drivers/media/v4l2-core/videobuf2-memops.c +++ b/drivers/media/v4l2-core/videobuf2-memops.c @@ -96,10 +96,10 @@ static void vb2_common_vm_open(struct vm_area_struct *vma) struct vb2_vmarea_handler *h = vma->vm_private_data; pr_debug("%s: %p, refcount: %d, vma: %08lx-%08lx\n", - __func__, h, atomic_read(h->refcount), vma->vm_start, + __func__, h, refcount_read(h->refcount), vma->vm_start, vma->vm_end); - atomic_inc(h->refcount); + refcount_inc(h->refcount); } /** @@ -114,7 +114,7 @@ static void vb2_common_vm_close(struct vm_area_struct *vma) struct vb2_vmarea_handler *h = vma->vm_private_data; pr_debug("%s: %p, refcount: %d, vma: %08lx-%08lx\n", - __func__, h, atomic_read(h->refcount), vma->vm_start, + __func__, h, refcount_read(h->refcount), vma->vm_start, vma->vm_end); h->put(h->arg); diff --git a/include/media/videobuf2-memops.h b/include/media/videobuf2-memops.h index 36565c7a..a6ed091 100644 --- a/include/media/videobuf2-memops.h +++ b/include/media/videobuf2-memops.h @@ -16,6 +16,7 @@ #include #include +#include /** * struct vb2_vmarea_handler - common vma refcount tracking handler @@ -25,7 +26,7 @@ * @arg: argument for @put callback */ struct vb2_vmarea_handler { - atomic_t *refcount; + refcount_t *refcount; void (*put)(void *arg); void *arg; }; -- 2.7.4