From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED, USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CAF95C433E0 for ; Sat, 9 Jan 2021 00:22:36 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 87F0D23A69 for ; Sat, 9 Jan 2021 00:22:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 87F0D23A69 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=mediatek.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Date:To:From: Subject:Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=/s+sjDphxZ7IcQhUuJVnWcULjtauGJjBWC4dG1nisPo=; b=JlbnIRm2Ob635wT8tML/NDHgY iyaVcR4umS1sZGUZxmNNIZwHGnkQoe70ctFu6MmOUKT1qz6Rrdd4jbU6At53bI9UoviSdEd6mef7O 0tFm5duo7bGSSZNigPgT/VRD1ULW13cLGguvmOvQyoJvGCogRxA1tBEYtU2d6o+ImAGI+fZPZUtjt lytHw0sKLcFBrGa9ZNqTxfwK8/Ovjqat916SiQ7jitHsa1i843/FXsujw2mzqfYgcLtJLel2zNUzO 6LgGSkLNkzYVDtd1lsjGj4ow9rxIRqn7gizUF4WoY4C7hX/47XXPROKomrEVZ/UE346dSOouHneoi 2bpwKjHlw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ky21Q-0004pF-B4; Sat, 09 Jan 2021 00:22:24 +0000 Received: from mailgw02.mediatek.com ([216.200.240.185]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1ky21N-0004oU-9S for linux-mediatek@lists.infradead.org; Sat, 09 Jan 2021 00:22:22 +0000 X-UUID: d92e53e7898945d6b6b3db7b9cbbedff-20210108 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Transfer-Encoding:MIME-Version:Content-Type:References:In-Reply-To:Date:CC:To:From:Subject:Message-ID; bh=7CYUlKecezZ1BJCyWACsMHG9HSdAtzLwoRJDZJLvlmg=; b=u1nu8GhD3Ns6FKKIPusbT9IGyEvJIMTVgyiiqwP5mQaWrOqzbcKO1uymHfKBhIXPmakY4G0XIrYXFkBsVN88MP+StPa9yWXdFuwIT/gCVOspPpEC514XbTYTwX18bcf9/9otufKmOKZSLeNXg72P3rEeQos+8jlctugh+rr9Fqk=; X-UUID: d92e53e7898945d6b6b3db7b9cbbedff-20210108 Received: from mtkcas67.mediatek.inc [(172.29.193.45)] by mailgw02.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 535487638; Fri, 08 Jan 2021 16:22:16 -0800 Received: from MTKMBS06N1.mediatek.inc (172.21.101.129) by MTKMBS62DR.mediatek.inc (172.29.94.18) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Fri, 8 Jan 2021 16:22:15 -0800 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkmbs06n1.mediatek.inc (172.21.101.129) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Sat, 9 Jan 2021 08:22:13 +0800 Received: from [172.21.77.33] (172.21.77.33) by mtkcas11.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Sat, 9 Jan 2021 08:22:13 +0800 Message-ID: <1610151733.9343.3.camel@mtkswgap22> Subject: Re: [PATCH] mac80211: fix incorrect strlen of .write in debugfs From: Ryder Lee To: Johannes Berg Date: Sat, 9 Jan 2021 08:22:13 +0800 In-Reply-To: <0efec65815ff9e26b3da69cb35d503a90086760c.camel@sipsolutions.net> References: <20210108105643.10834-1-shayne.chen@mediatek.com> <0efec65815ff9e26b3da69cb35d503a90086760c.camel@sipsolutions.net> X-Mailer: Evolution 3.2.3-0ubuntu6 MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210108_192221_521388_7C04AA24 X-CRM114-Status: GOOD ( 15.89 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Toke =?ISO-8859-1?Q?H=F8iland-J=F8rgensen?= , linux-wireless , linux-mediatek , Sujuan Chen , Lorenzo Bianconi , Felix Fietkau , Shayne Chen Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On Fri, 2021-01-08 at 21:02 +0100, Johannes Berg wrote: > This looks wrong to me, am I missing something? > > > diff --git a/net/mac80211/debugfs.c b/net/mac80211/debugfs.c > > index 9135b6f..9991a6a 100644 > > --- a/net/mac80211/debugfs.c > > +++ b/net/mac80211/debugfs.c > > @@ -120,7 +120,6 @@ static ssize_t aqm_write(struct file *file, > > { > > struct ieee80211_local *local = file->private_data; > > char buf[100]; > > - size_t len; > > > > if (count > sizeof(buf)) > > return -EINVAL; > > This ensures that count <= sizeof(buf) > > > @@ -128,10 +127,10 @@ static ssize_t aqm_write(struct file *file, > > if (copy_from_user(buf, user_buf, count)) > > return -EFAULT; > > We copy, that's fine. > > > - buf[sizeof(buf) - 1] = '\0'; > > - len = strlen(buf); > > - if (len > 0 && buf[len-1] == '\n') > > - buf[len-1] = 0; > > + if (count && buf[count - 1] == '\n') > > + buf[count - 1] = '\0'; > > This I think really was meant as strlen, because if you write something > like > > 10\n\0\0\0\0 > > before it would have parsed it as 10 still, now it gets confused? > > I guess I'm not worried about that though. I think the problem only happens on airtime_flags_write() that uses kstrtou16() > > + buf[count] = '\0'; > > But if count == sizeof(buf) then this is an out-of-bounds write. Right. Then, we can if (count >= sizeof(buf)) return -EINVAL; Ryder _______________________________________________ Linux-mediatek mailing list Linux-mediatek@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-mediatek From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B334C433DB for ; Sat, 9 Jan 2021 00:23:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4E7BA23A69 for ; Sat, 9 Jan 2021 00:23:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726216AbhAIAXD (ORCPT ); Fri, 8 Jan 2021 19:23:03 -0500 Received: from mailgw01.mediatek.com ([210.61.82.183]:34458 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1725872AbhAIAXD (ORCPT ); Fri, 8 Jan 2021 19:23:03 -0500 X-UUID: 2087cc9e142449a1a487af29da6a1889-20210109 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Transfer-Encoding:MIME-Version:Content-Type:References:In-Reply-To:Date:CC:To:From:Subject:Message-ID; bh=7CYUlKecezZ1BJCyWACsMHG9HSdAtzLwoRJDZJLvlmg=; b=EE1lsKQzli67viq9PmMnk8mcQizuxp5/LSQ6t0dhVoH2AHSULATmxaaZI66AsF9lq+7yVIoVOvY37OG71mk1zwR1+nPohCTa152KZfBmPJgSD7wnn9nJjLW+YyV7f4Uz0R1G7uo+2CQsiWlgALvimfvgWUHJWcRHwAE76AdmGUE=; X-UUID: 2087cc9e142449a1a487af29da6a1889-20210109 Received: from mtkcas10.mediatek.inc [(172.21.101.39)] by mailgw01.mediatek.com (envelope-from ) (Cellopoint E-mail Firewall v4.1.14 Build 0819 with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 693531631; Sat, 09 Jan 2021 08:22:16 +0800 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkmbs06n1.mediatek.inc (172.21.101.129) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Sat, 9 Jan 2021 08:22:13 +0800 Received: from [172.21.77.33] (172.21.77.33) by mtkcas11.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Sat, 9 Jan 2021 08:22:13 +0800 Message-ID: <1610151733.9343.3.camel@mtkswgap22> Subject: Re: [PATCH] mac80211: fix incorrect strlen of .write in debugfs From: Ryder Lee To: Johannes Berg CC: Shayne Chen , linux-wireless , Toke =?ISO-8859-1?Q?H=F8iland-J=F8rgensen?= , linux-mediatek , Sujuan Chen , Lorenzo Bianconi , Felix Fietkau Date: Sat, 9 Jan 2021 08:22:13 +0800 In-Reply-To: <0efec65815ff9e26b3da69cb35d503a90086760c.camel@sipsolutions.net> References: <20210108105643.10834-1-shayne.chen@mediatek.com> <0efec65815ff9e26b3da69cb35d503a90086760c.camel@sipsolutions.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 MIME-Version: 1.0 X-MTK: N Content-Transfer-Encoding: base64 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org T24gRnJpLCAyMDIxLTAxLTA4IGF0IDIxOjAyICswMTAwLCBKb2hhbm5lcyBCZXJnIHdyb3RlOg0K PiBUaGlzIGxvb2tzIHdyb25nIHRvIG1lLCBhbSBJIG1pc3Npbmcgc29tZXRoaW5nPw0KPiANCj4g PiBkaWZmIC0tZ2l0IGEvbmV0L21hYzgwMjExL2RlYnVnZnMuYyBiL25ldC9tYWM4MDIxMS9kZWJ1 Z2ZzLmMNCj4gPiBpbmRleCA5MTM1YjZmLi45OTkxYTZhIDEwMDY0NA0KPiA+IC0tLSBhL25ldC9t YWM4MDIxMS9kZWJ1Z2ZzLmMNCj4gPiArKysgYi9uZXQvbWFjODAyMTEvZGVidWdmcy5jDQo+ID4g QEAgLTEyMCw3ICsxMjAsNiBAQCBzdGF0aWMgc3NpemVfdCBhcW1fd3JpdGUoc3RydWN0IGZpbGUg KmZpbGUsDQo+ID4gIHsNCj4gPiAgCXN0cnVjdCBpZWVlODAyMTFfbG9jYWwgKmxvY2FsID0gZmls ZS0+cHJpdmF0ZV9kYXRhOw0KPiA+ICAJY2hhciBidWZbMTAwXTsNCj4gPiAtCXNpemVfdCBsZW47 DQo+ID4gIA0KPiA+ICAJaWYgKGNvdW50ID4gc2l6ZW9mKGJ1ZikpDQo+ID4gIAkJcmV0dXJuIC1F SU5WQUw7DQo+IA0KPiBUaGlzIGVuc3VyZXMgdGhhdCBjb3VudCA8PSBzaXplb2YoYnVmKQ0KPiAN Cj4gPiBAQCAtMTI4LDEwICsxMjcsMTAgQEAgc3RhdGljIHNzaXplX3QgYXFtX3dyaXRlKHN0cnVj dCBmaWxlICpmaWxlLA0KPiA+ICAJaWYgKGNvcHlfZnJvbV91c2VyKGJ1ZiwgdXNlcl9idWYsIGNv dW50KSkNCj4gPiAgCQlyZXR1cm4gLUVGQVVMVDsNCj4gDQo+IFdlIGNvcHksIHRoYXQncyBmaW5l Lg0KPiAgDQo+ID4gLQlidWZbc2l6ZW9mKGJ1ZikgLSAxXSA9ICdcMCc7DQo+ID4gLQlsZW4gPSBz dHJsZW4oYnVmKTsNCj4gPiAtCWlmIChsZW4gPiAwICYmIGJ1ZltsZW4tMV0gPT0gJ1xuJykNCj4g PiAtCQlidWZbbGVuLTFdID0gMDsNCj4gPiArCWlmIChjb3VudCAmJiBidWZbY291bnQgLSAxXSA9 PSAnXG4nKQ0KPiA+ICsJCWJ1Zltjb3VudCAtIDFdID0gJ1wwJzsNCj4gDQo+IFRoaXMgSSB0aGlu ayByZWFsbHkgd2FzIG1lYW50IGFzIHN0cmxlbiwgYmVjYXVzZSBpZiB5b3Ugd3JpdGUgc29tZXRo aW5nDQo+IGxpa2UNCj4gDQo+ICAxMFxuXDBcMFwwXDANCj4gDQo+IGJlZm9yZSBpdCB3b3VsZCBo YXZlIHBhcnNlZCBpdCBhcyAxMCBzdGlsbCwgbm93IGl0IGdldHMgY29uZnVzZWQ/DQo+IA0KPiBJ IGd1ZXNzIEknbSBub3Qgd29ycmllZCBhYm91dCB0aGF0IHRob3VnaC4NCg0KSSB0aGluayB0aGUg cHJvYmxlbSBvbmx5IGhhcHBlbnMgb24gYWlydGltZV9mbGFnc193cml0ZSgpIHRoYXQgdXNlcw0K a3N0cnRvdTE2KCkNCg0KDQo+ID4gKwlidWZbY291bnRdID0gJ1wwJzsNCj4gDQo+IEJ1dCBpZiBj b3VudCA9PSBzaXplb2YoYnVmKSB0aGVuIHRoaXMgaXMgYW4gb3V0LW9mLWJvdW5kcyB3cml0ZS4N Cg0KUmlnaHQuIFRoZW4sIHdlIGNhbg0KDQogCWlmIChjb3VudCA+PSBzaXplb2YoYnVmKSkNCgkJ cmV0dXJuIC1FSU5WQUw7DQoNClJ5ZGVyDQoNCg0KDQo=