From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751917AbdHHAvx (ORCPT ); Mon, 7 Aug 2017 20:51:53 -0400 Received: from mailout2.samsung.com ([203.254.224.25]:19986 "EHLO mailout2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751386AbdHHAvu (ORCPT ); Mon, 7 Aug 2017 20:51:50 -0400 X-AuditID: b6c32a46-f790d6d000003bf5-0b-59890b231a95 MIME-version: 1.0 Content-transfer-encoding: 8BIT Content-type: text/plain; charset="UTF-8" Message-id: <59890B25.9090506@samsung.com> Date: Tue, 08 Aug 2017 09:51:49 +0900 From: Chanwoo Choi Organization: Samsung Electronics User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 To: Santosh Mardi , myungjoo.ham@samsung.com, kyungmin.park@samsung.com, rafael.j.wysocki@intel.com Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, gsantosh@qti.qualcomm.com, skannan@quicinc.com, rgottimu@qti.qualcomm.com Subject: Re: [PATCH] devfreq: add error check for sscanf in userspace governor In-reply-to: <1502111205-22560-2-git-send-email-gsantosh@codeaurora.org> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrAJsWRmVeSWpSXmKPExsWy7bCmua4Kd2ekwZqLzBZfj2xisdhw7xOz xdmmN+wWl3fNYbP43HuE0eJ24wo2i8cr3rJbNGy5y2jxe0EvqwOnx+W+XiaPxXteMnksmvqM 0WPinjqPvi2rGD0+b5ILYItKtclITUxJLVJIzUvOT8nMS7dV8g6Od443NTMw1DW0tDBXUshL zE21VXLxCdB1y8wBOkpJoSwxpxQoFJBYXKykb2dTlF9akqqQkV9cYqsUbWhopGdoYK5nZGSk Z2Ica2VkClSSkJqx5+gt1oJJXBUPL6Q3ME7j6GLk4JAQMJF4tz69i5ETyBSTuHBvPVsXIxeH kMAORomNm3azQzifGSWer1jOBlFlIrHt/mRWiMRaRonml69YQRK8AoISPybfYwGZyiwgL3Hk UjZImFlAU2Lr7vVQg+4xSnR0NDNB1GtJtJx4xAxiswioSsze8ZYdxGYDiu9/cQNsGb+AosTV H48ZQWxRgQiJnfO/gdWICNRJNKxYygIylFmgnVHiW/cesCJhgQCJ7mUXwGxOAQ+JAyv+gBVJ CFxil1j0ZzsjxM+yEpsOMEOYLhJHtwtAPCYs8er4FnYIW0qiu2MWO0Qr0PzNc+5BzelglLi/ spEVospY4lRXIxPEm3wSHYf/skMM5ZXoaBOCKPGQ+HtrCSOE7SjxYlcXIyQkbjJKrFx5gH0C o8IspMCbhQi8WUiBt4CReRWjWGpBcW56arFRgZFecWJucWleul5yfu4mRnDq1HLbwbjknM8h RgEORiUe3hVpHZFCrIllxZW5hxglOJiVRHh/cnRGCvGmJFZWpRblxxeV5qQWH2I0BYb9RGYp 0eR8YFrPK4k3NLE0MDEzMzI3swCmO3Heum3XIoQE0hNLUrNTUwtSi2D6mDg4pRoYQ7I+V07X vXr0X9OjW3Ua3MKTvzBUtE5IOLdT/vt5/90J7n0W1xfrzz/Mf71kZ9uLGQs8re6n2uv9ufRh ubhu1uvUGykTN22fIeZdu6FY9XLStkuaOoGTDPNLH3XucTnsY2DIkLE3w2+tuZP1wsWVVwOq Zm2scCp8/Pwzw8tF+2PLqjlnypleVmIpzkg01GIuKk4EAOagxPKzAwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrFIsWRmVeSWpSXmKPExsVy+t9jQV1l7s5Ig+dTDS2+HtnEYrHh3idm i7NNb9gtLu+aw2bxufcIo8XtxhVsFo9XvGW3aNhyl9Hi94JeVgdOj8t9vUwei/e8ZPJYNPUZ o8fEPXUefVtWMXp83iQXwBblZpORmpiSWqSQmpecn5KZl26rFBripmuhpJCXmJtqqxSh6xsS pKRQlphTCuQZGaABB+cA92AlfbsEt4w9R2+xFkziqnh4Ib2BcRpHFyMnh4SAicS2+5NZIWwx iQv31rN1MXJxCAmsZpTYcWURI0iCV0BQ4sfkeyxdjBwczALyEkcuZYOEmQXUJSbNW8QMUf+A UeLk3YVsEPVaEi0nHjGD2CwCqhKzd7xlB7HZgOL7X9wAq+EXUJS4+uMxI8hMUYEIie4TlSBh EYE6if6HbUwgM5kF2hklrh3cxQSSEBbwkzjV+wusV0jgJqNE02dzEJtTwEPiwIo/LBMYBWch OXUWwqmzkJy6gJF5FaNYakFxbnpusVGBkV5xYm5xaV66XnJ+7iZGYDxuO6wVsIOx6Vz0IUYB DkYlHl6GzI5IIdbEsuLK3EOMEhzMSiK8Pzk6I4V4UxIrq1KL8uOLSnNSiw8xmgJ9OpFZSjQ5 H5gq8kriDU0sjUwMzMwMjQyMzZTEeScEfokQEkhPLEnNTk0tSC2C6WPi4JRqYNyi1ScxOzL+ mf2e/c2d0bfu+Gy9ef+1ctfMzx+Lrp99vHGZfOGJ4xtyTJc3tU+8XJRy6vFXg9chz5c3n3wa Vau2j1/E3spOe2HsGeEzwudLZDSC1LhfmIgtkBI4rfI5JjLMwuPf9ZvfubbfuJwUz31ow58b 8R+Ygz/l1FduWsOlHrmhf7PXlaVKLMUZiYZazEXFiQDu08jn3QIAAA== X-MTR: 20000000000000000@CPGS X-CMS-MailID: 20170808005147epcas2p1f747bc0915e1625f7d30eaae331eb029 X-Msg-Generator: CA X-Sender-IP: 182.195.42.80 X-Local-Sender: =?UTF-8?B?7LWc7LCs7JqwG1RpemVuIFBsYXRmb3JtIExhYihTL1fshLw=?= =?UTF-8?B?7YSwKRvsgrzshLHsoITsnpAbU2VuaW9yIEVuZ2luZWVy?= X-Global-Sender: =?UTF-8?B?Q2hhbndvbyBDaG9pG1RpemVuIFBsYXRmb3JtIExhYi4bU2Ft?= =?UTF-8?B?c3VuZyBFbGVjdHJvbmljcxtTZW5pb3IgRW5naW5lZXI=?= X-Sender-Code: =?UTF-8?B?QzEwG1RFTEUbQzEwVjgxMTE=?= CMS-TYPE: 102P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20170807130749epcas2p3052fee64e962d1013f94a850c89550f4 X-RootMTR: 20170807130749epcas2p3052fee64e962d1013f94a850c89550f4 References: <1502111205-22560-1-git-send-email-gsantosh@codeaurora.org> <1502111205-22560-2-git-send-email-gsantosh@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 2017년 08월 07일 22:06, Santosh Mardi wrote: > store_freq function of devfreq userspace governor > executes further, even if error is returned from sscanf, > this will result in setting up wrong frequency value. > > Add proper error check to bail out if any error is returned. > > Signed-off-by: Santosh Mardi > --- > drivers/devfreq/governor_userspace.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/devfreq/governor_userspace.c b/drivers/devfreq/governor_userspace.c > index 77028c2..1d0c9cc 100644 > --- a/drivers/devfreq/governor_userspace.c > +++ b/drivers/devfreq/governor_userspace.c > @@ -53,12 +53,15 @@ static ssize_t store_freq(struct device *dev, struct device_attribute *attr, > mutex_lock(&devfreq->lock); > data = devfreq->data; > > - sscanf(buf, "%lu", &wanted); > + err = sscanf(buf, "%lu", &wanted); > + if (err != 1) > + goto out; > data->user_frequency = wanted; > data->valid = true; > err = update_devfreq(devfreq); > if (err == 0) > err = count; > +out: > mutex_unlock(&devfreq->lock); > return err; > } > Looks good to me. Reviewed-by: Chanwoo Choi -- Best Regards, Chanwoo Choi Samsung Electronics