From: Weidong Wang Subject: Re: bgmac: fix a missing check for build_skb Date: Wed, 13 Jan 2016 19:31:59 +0800 Message-ID: <569635AF.4070204@huawei.com> References: <5695BF41.2040002@huawei.com> <1452674087.4516.3.camel@redhat.com> <5696262D.3040803@huawei.com> <56962DAF.9040807@openwrt.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Paolo Abeni , David Miller , , , Joe Perches , , , To: Felix Fietkau Return-path: In-Reply-To: <56962DAF.9040807@openwrt.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 2016/1/13 18:57, Felix Fietkau wrote: > On 2016-01-13 11:25, Weidong Wang wrote: >> On 2016/1/13 16:34, Paolo Abeni wrote: >>> On Wed, 2016-01-13 at 11:06 +0800, Weidong Wang wrote: >>>> when build_skb failed, it may occure a NULL pointer. >>>> So add a 'NULL check' for it. >>>> >>>> Signed-off-by: Weidong Wang >>>> --- >>>> drivers/net/ethernet/broadcom/bgmac.c | 5 +++++ >>>> 1 file changed, 5 insertions(+) >>>> >>>> diff --git a/drivers/net/ethernet/broadcom/bgmac.c b/drivers/net/ethernet/broadcom/bgmac.c >>>> index 21e3c38..d75180a 100644 >>>> --- a/drivers/net/ethernet/broadcom/bgmac.c >>>> +++ b/drivers/net/ethernet/broadcom/bgmac.c >>>> @@ -466,6 +466,11 @@ static int bgmac_dma_rx_read(struct bgmac *bgmac, struct bgmac_dma_ring *ring, >>>> len -= ETH_FCS_LEN; >>>> >>>> skb = build_skb(buf, BGMAC_RX_ALLOC_SIZE); >>>> + if (unlikely(skb)) { >>> >>> Should that be instead: >>> >>> if (unlikely(!skb)) { >>> >>> ? >>> >> >> What to instead of it? > Your patch has a logic error (missing the !), and it's breaking the > ethernet driver completely instead of fixing anything. > Did you even test this? > Yep, you are right. Sorry for that. I just review the source code without any test. I should resent it again. > Dave, why did you apply this patch so fast without any chance of review? > > - Felix > > . > Regards, Weidong