Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933595AbcJRIzU (ORCPT ); Tue, 18 Oct 2016 04:55:20 -0400 Received: from mail-yw0-f177.google.com ([209.85.161.177]:35404 "EHLO mail-yw0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932533AbcJRIzP (ORCPT ); Tue, 18 Oct 2016 04:55:15 -0400 MIME-Version: 1.0 In-Reply-To: <20161018084343.680-1-maxime.ripard@free-electrons.com> References: <20161018084343.680-1-maxime.ripard@free-electrons.com> From: Baolin Wang Date: Tue, 18 Oct 2016 16:55:14 +0800 Message-ID: Subject: Re: [PATCH] mmc: core: Check regulator pointer To: Maxime Ripard Cc: Ulf Hansson , linux-mmc , LKML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1569 Lines: 51 Hi, On 18 October 2016 at 16:43, Maxime Ripard wrote: > mmc_regulator_get_supply might silently fail if the regulators are not > found, which is the right thing to do since both these regulators are > optional. > > However, the drivers then have no way to know whether or not they should > proceed and call mmc_regulator_set_ocr. And since this function doesn't > check for the validity of the regulator pointer, it leads to a null pointer > dereference. Add such a check to make sure everything works fine. > > Signed-off-by: Maxime Ripard > --- > drivers/mmc/core/core.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c > index 2553d903a82b..1d3ea5e1aa37 100644 > --- a/drivers/mmc/core/core.c > +++ b/drivers/mmc/core/core.c > @@ -1474,6 +1474,12 @@ int mmc_regulator_set_ocr(struct mmc_host *mmc, > int result = 0; > int min_uV, max_uV; > > + if (!supply) > + return -EINVAL; > + > + if (IS_ERR(supply)) > + return PTR_ERR(supply); You can simply these checking with IS_ERR_OR_NULL(). > + > if (vdd_bit) { > mmc_ocrbitnum_to_vdd(vdd_bit, &min_uV, &max_uV); > > -- > 2.9.3 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Baolin.wang Best Regards