From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754516AbdCFOdJ (ORCPT ); Mon, 6 Mar 2017 09:33:09 -0500 Received: from mga03.intel.com ([134.134.136.65]:19238 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754391AbdCFO3s (ORCPT ); Mon, 6 Mar 2017 09:29:48 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.35,254,1484035200"; d="scan'208";a="72746261" 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 16/29] drivers, media: convert vb2_vmalloc_buf.refcount from atomic_t to refcount_t Date: Mon, 6 Mar 2017 16:21:03 +0200 Message-Id: <1488810076-3754-17-git-send-email-elena.reshetova@intel.com> X-Mailer: git-send-email 2.7.4 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: X-Mailing-List: linux-kernel@vger.kernel.org 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-vmalloc.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/media/v4l2-core/videobuf2-vmalloc.c b/drivers/media/v4l2-core/videobuf2-vmalloc.c index 3f77814..f83253a 100644 --- a/drivers/media/v4l2-core/videobuf2-vmalloc.c +++ b/drivers/media/v4l2-core/videobuf2-vmalloc.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -26,7 +27,7 @@ struct vb2_vmalloc_buf { struct frame_vector *vec; enum dma_data_direction dma_dir; unsigned long size; - atomic_t refcount; + refcount_t refcount; struct vb2_vmarea_handler handler; struct dma_buf *dbuf; }; @@ -56,7 +57,7 @@ static void *vb2_vmalloc_alloc(struct device *dev, unsigned long attrs, return ERR_PTR(-ENOMEM); } - atomic_inc(&buf->refcount); + refcount_set(&buf->refcount, 1); return buf; } @@ -64,7 +65,7 @@ static void vb2_vmalloc_put(void *buf_priv) { struct vb2_vmalloc_buf *buf = buf_priv; - if (atomic_dec_and_test(&buf->refcount)) { + if (refcount_dec_and_test(&buf->refcount)) { vfree(buf->vaddr); kfree(buf); } @@ -161,7 +162,7 @@ static void *vb2_vmalloc_vaddr(void *buf_priv) static unsigned int vb2_vmalloc_num_users(void *buf_priv) { struct vb2_vmalloc_buf *buf = buf_priv; - return atomic_read(&buf->refcount); + return refcount_read(&buf->refcount); } static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma) @@ -368,7 +369,7 @@ static struct dma_buf *vb2_vmalloc_get_dmabuf(void *buf_priv, unsigned long flag return NULL; /* dmabuf keeps reference to vb2 buffer */ - atomic_inc(&buf->refcount); + refcount_inc(&buf->refcount); return dbuf; } -- 2.7.4