From patchwork Sun Dec 26 20:57:39 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jesper Juhl X-Patchwork-Id: 76724 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id B5F23B6EE9 for ; Mon, 27 Dec 2010 08:07:55 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752697Ab0LZVHS (ORCPT ); Sun, 26 Dec 2010 16:07:18 -0500 Received: from swampdragon.chaosbits.net ([90.184.90.115]:18742 "EHLO swampdragon.chaosbits.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752541Ab0LZVHR (ORCPT ); Sun, 26 Dec 2010 16:07:17 -0500 Received: by swampdragon.chaosbits.net (Postfix, from userid 1000) id A6FE29403F; Sun, 26 Dec 2010 21:57:39 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by swampdragon.chaosbits.net (Postfix) with ESMTP id 9F2469403B; Sun, 26 Dec 2010 21:57:39 +0100 (CET) Date: Sun, 26 Dec 2010 21:57:39 +0100 (CET) From: Jesper Juhl To: Joe Perches cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "John(Zongxi) Chen" , Michael Chan Subject: [PATCH v2] Broadcom CNIC core network driver: fix mem leak on allocation failures in cnic_alloc_uio_rings() In-Reply-To: <1293396850.7726.14.camel@Joe-Laptop> Message-ID: References: <1293396850.7726.14.camel@Joe-Laptop> User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sun, 26 Dec 2010, Joe Perches wrote: > On Sun, 2010-12-26 at 21:30 +0100, Jesper Juhl wrote: > > We are leaking memory in drivers/net/cnic.c::cnic_alloc_uio_rings() if > > either of the calls to dma_alloc_coherent() fail. > > Signed-off-by: Jesper Juhl > > cnic.c | 10 ++++++++-- > > diff --git a/drivers/net/cnic.c b/drivers/net/cnic.c > [] > > - if (!udev->l2_ring) > > + if (!udev->l2_ring) { > > + kfree(udev); > > return -ENOMEM; > > + } > [] > > - if (!udev->l2_buf) > > + if (!udev->l2_buf) { > > + dma_free_coherent(&udev->pdev->dev, udev->l2_ring_size, > > + udev->l2_ring, udev->l2_ring_map); > > + kfree(udev); > > return -ENOMEM; > > + } > > Perhaps this would be more standard with a goto error / exit block > > err_dma: > dma_free_coherent(); > err_udev: > kfree(udev); > return -ENOMEM; > I have no problem with that. It's functionally the same, but the object file size is smaller and, as you say, it's more standard. Good point, thanks. We are leaking memory in drivers/net/cnic.c::cnic_alloc_uio_rings() if either of the calls to dma_alloc_coherent() fail. This patch fixes it by freeing both the memory allocated with kzalloc() and memory allocated with previous calls to dma_alloc_coherent() when there's a failure. Thanks to Joe Perches for suggesting a better implementation than my initial version. Signed-off-by: Jesper Juhl Acked-by: Michael Chan --- cnic.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) compile tested only since I don't have the hardware to do a proper test. diff --git a/drivers/net/cnic.c b/drivers/net/cnic.c index 92bac19..952afac 100644 --- a/drivers/net/cnic.c +++ b/drivers/net/cnic.c @@ -940,7 +940,7 @@ static int cnic_alloc_uio_rings(struct cnic_dev *dev, int pages) &udev->l2_ring_map, GFP_KERNEL | __GFP_COMP); if (!udev->l2_ring) - return -ENOMEM; + goto err_udev; udev->l2_buf_size = (cp->l2_rx_ring_size + 1) * cp->l2_single_buf_size; udev->l2_buf_size = PAGE_ALIGN(udev->l2_buf_size); @@ -948,7 +948,7 @@ static int cnic_alloc_uio_rings(struct cnic_dev *dev, int pages) &udev->l2_buf_map, GFP_KERNEL | __GFP_COMP); if (!udev->l2_buf) - return -ENOMEM; + goto err_dma; write_lock(&cnic_dev_lock); list_add(&udev->list, &cnic_udev_list); @@ -959,6 +959,12 @@ static int cnic_alloc_uio_rings(struct cnic_dev *dev, int pages) cp->udev = udev; return 0; + err_dma: + dma_free_coherent(&udev->pdev->dev, udev->l2_ring_size, + udev->l2_ring, udev->l2_ring_map); + err_udev: + kfree(udev); + return -ENOMEM; } static int cnic_init_uio(struct cnic_dev *dev)