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[209.132.180.67]) by mx.google.com with ESMTP id 33si8162076pli.144.2019.07.12.10.47.09; Fri, 12 Jul 2019 10:47:25 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b="bgR/1MOC"; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727415AbfGLRqh (ORCPT + 99 others); Fri, 12 Jul 2019 13:46:37 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:43181 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727079AbfGLRqh (ORCPT ); Fri, 12 Jul 2019 13:46:37 -0400 Received: by mail-wr1-f67.google.com with SMTP id p13so10772354wru.10; Fri, 12 Jul 2019 10:46:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=VnGi7SmrRgQ+WlkfWjtNW9trIO/foZCB9eqZJyvYBXY=; b=bgR/1MOCBglV8ju8A0TSc632QFLLjYW8p0VnNd9PAek5sXuIdXM5V2hh8TBrkfgdOy Dw8/WWEh/XAGtToU23dd6m3uiGQd+2q+5ldaWJVeVVVIY+XcSpCcSb1MeYCRnrEiA6Jq ZiEhpp0T9Cu2pgT07L4XJTYo+VLqeclH+FOwnq9GMOu9YDpLwzRJy3zQzpsxhAwvHRAA WgAED6zF107ZM7qm0wRE3uGFdq7ntKqaavbU+4Dwqw+TA0q3P+n0RZ15rvVtEwhsFmxi OiliIC9mpmGn/DQthcPU0rsjUOMIy3kkYgEyOh5XBOJafCtORoodjoHlki3450FY8F8d NKfw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=VnGi7SmrRgQ+WlkfWjtNW9trIO/foZCB9eqZJyvYBXY=; b=rFWuO8P5bbpPFmQnZpnYE6S1yYG6ylaoYZUYawew9Edf4UQ3yVopO+M25xoFo3/C9v 7vcrwvtg2zjemBtXgz00CnikOAerzcoI9Ao3gRl/yj7O8UCouwHgIMgsW31/JhTdu65U BBJCkp8umeEuQbrHYfKgp/uESvnemaz+gX8UwhFAAc7TEq9ZibaeOnD7T6rYbvrnfmHx ZPsKPSC3CTX4sj1Ad/3dbe7mF2nLTHpuwxOK5FrohNDP3IGaxnSbyWgcl4gaEw/RtZv/ XPUfTPxPSrf/XsYbaLK5dDXr739xhKIPHBpDGkiLQF/A7IH7+XCrl3CMNYwf9nh8X3yU tDVQ== X-Gm-Message-State: APjAAAXaab0J4cwPTb3OEsLk62wBaiMT0GMRmIyG0lDYEyXw1eA2aFub ucYbe3zOl8ibQyXuT87T5YhNIPs= X-Received: by 2002:adf:ebcd:: with SMTP id v13mr12621145wrn.263.1562953595046; Fri, 12 Jul 2019 10:46:35 -0700 (PDT) Received: from avx2 ([46.53.248.114]) by smtp.gmail.com with ESMTPSA id c12sm14210038wrd.21.2019.07.12.10.46.33 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 12 Jul 2019 10:46:34 -0700 (PDT) Date: Fri, 12 Jul 2019 20:46:32 +0300 From: Alexey Dobriyan To: Oleg Nesterov Cc: Alexey Izbyshev , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, security@kernel.org Subject: Re: [PATCH] proc: Fix uninitialized byte read in get_mm_cmdline() Message-ID: <20190712174632.GA3175@avx2> References: <20190712160913.17727-1-izbyshev@ispras.ru> <20190712163625.GF21989@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190712163625.GF21989@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 12, 2019 at 06:36:26PM +0200, Oleg Nesterov wrote: > On 07/12, Alexey Izbyshev wrote: > > > > --- a/fs/proc/base.c > > +++ b/fs/proc/base.c > > @@ -275,6 +275,8 @@ static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf, > > if (got <= offset) > > break; > > got -= offset; > > + if (got < size) > > + size = got; > > Acked-by: Oleg Nesterov The proper fix to all /proc/*/cmdline problems is to revert f5b65348fd77839b50e79bc0a5e536832ea52d8d proc: fix missing final NUL in get_mm_cmdline() rewrite 5ab8271899658042fabc5ae7e6a99066a210bc0e fs/proc: simplify and clarify get_mm_cmdline() function