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=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL 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 0777DC43603 for ; Fri, 20 Dec 2019 18:51:53 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C3F13206D8 for ; Fri, 20 Dec 2019 18:51:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="qkut3uN8" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C3F13206D8 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 783DD8E01C5; Fri, 20 Dec 2019 13:51:52 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 735CE8E019D; Fri, 20 Dec 2019 13:51:52 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6736A8E01C5; Fri, 20 Dec 2019 13:51:52 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0062.hostedemail.com [216.40.44.62]) by kanga.kvack.org (Postfix) with ESMTP id 5279E8E019D for ; Fri, 20 Dec 2019 13:51:52 -0500 (EST) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id F3A51181AEF15 for ; Fri, 20 Dec 2019 18:51:51 +0000 (UTC) X-FDA: 76286414022.23.jar82_84a0f03f8bd37 X-HE-Tag: jar82_84a0f03f8bd37 X-Filterd-Recvd-Size: 5871 Received: from mail-wm1-f74.google.com (mail-wm1-f74.google.com [209.85.128.74]) by imf22.hostedemail.com (Postfix) with ESMTP for ; Fri, 20 Dec 2019 18:51:51 +0000 (UTC) Received: by mail-wm1-f74.google.com with SMTP id p2so2835877wma.3 for ; Fri, 20 Dec 2019 10:51:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=Zt2fd00LLmd0KtmWJuqorKg/3EOSA1eH2GgEantFHxk=; b=qkut3uN84bGE+PJuoSFDzqTAPAEL7MzeZFk3htOafxjk2ImGQs1eiYtejUHSirqsPE ZMHDmNY8TtA6zfrXgctjhPmE8JaaBQ2G48KNjWpjVU/mgCzL35D9dIqcpZAbuPeNaSZT WJVcASLrXiMvd1v3ZPoZyqCKwLZjV+uCO0jQWGj2p38si1IihFERlV42Xy0c1vNcmYLc 7imjcikqBdqxg7TWWYKHsKIblZG/8xEYUa9/cZ9KsdK6e/lCl/y9VovJVsNw4zie2TXD I6AFrM72P03CTwseq13t2/5e3ldv27XSsLekZ+cIOHoVP26AxaJepZ3r5AQzr7XJkOkr Xt2Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=Zt2fd00LLmd0KtmWJuqorKg/3EOSA1eH2GgEantFHxk=; b=L4lKdIXeqIfa1vkb7mKKWPNRTgqnRTOUqdZDoU+Yba0kb4NNAEH7aLERQOcfUIot9N feISYgKwy0ezTBX36SAiWDuwU/G1EIr1Ng032TxGaSXdWChdBwnkpmofuAmJqvJyEv0q ptMtjmhk4G6qYsak1X7UeWoJikAna7qgbmtbchYuRjY+S3PWz57hsIxhkccZ4BDWRGBp z0sGSmXvLiZQka6zGEIJ+skK9H/8jaAq+8gztEyFWmAUDKBBosa2YfeKgmjC9WlCHqHX GihHTKPOVpB3oG9jy+QDk+kboU+rCaIndHlXQfKXW0GHs+fgNz7F/l6aNp6aqVoqa9i7 tqjA== X-Gm-Message-State: APjAAAVG94d/f/+vV65DA3XvZ4/7lpCOP2KXlU4EIlzVfIHuVOqpobK1 x2qhBqXb1p4ieD6Rjc6nk3q1GJu5X6s= X-Google-Smtp-Source: APXvYqy0q/BmMeynj7UnUWnlqirFNOkytzBv3wSYzhgvKmJuauY4xO4vtg2e9DY3SiEWCoqyCUgsiSIwdWg= X-Received: by 2002:a5d:4d4a:: with SMTP id a10mr16904894wru.220.1576867909878; Fri, 20 Dec 2019 10:51:49 -0800 (PST) Date: Fri, 20 Dec 2019 19:49:47 +0100 In-Reply-To: <20191220184955.223741-1-glider@google.com> Message-Id: <20191220184955.223741-35-glider@google.com> Mime-Version: 1.0 References: <20191220184955.223741-1-glider@google.com> X-Mailer: git-send-email 2.24.1.735.g03f4e72817-goog Subject: [PATCH RFC v4 34/42] kmsan: handle /dev/[u]random From: glider@google.com To: Andrew Morton , Jens Axboe , "Theodore Ts'o" , Dmitry Torokhov , "Martin K. Petersen" , "Michael S. Tsirkin" , Christoph Hellwig , Eric Dumazet , Eric Van Hensbergen , Takashi Iwai , Vegard Nossum , Dmitry Vyukov , Marco Elver , Andrey Konovalov , Matthew Wilcox , linux-mm@kvack.org Cc: glider@google.com, viro@zeniv.linux.org.uk, adilger.kernel@dilger.ca, aryabinin@virtuozzo.com, luto@kernel.org, ard.biesheuvel@linaro.org, arnd@arndb.de, hch@infradead.org, darrick.wong@oracle.com, davem@davemloft.net, ebiggers@google.com, gregkh@linuxfoundation.org, harry.wentland@amd.com, herbert@gondor.apana.org.au, iii@linux.ibm.com, mingo@elte.hu, jasowang@redhat.com, m.szyprowski@samsung.com, mark.rutland@arm.com, schwidefsky@de.ibm.com, mhocko@suse.com, monstr@monstr.eu, pmladek@suse.com, cai@lca.pw, rdunlap@infradead.org, robin.murphy@arm.com, sergey.senozhatsky@gmail.com, rostedt@goodmis.org, tglx@linutronix.de, gor@linux.ibm.com, wsa@the-dreams.de Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: The random number generator may use uninitialized memory, but it may not return uninitialized values. Unpoison the output buffer in _extract_crng() to prevent false reports. Signed-off-by: Alexander Potapenko To: Alexander Potapenko Cc: Andrew Morton Cc: Jens Axboe Cc: "Theodore Ts'o" Cc: Dmitry Torokhov Cc: Martin K. Petersen Cc: "Michael S. Tsirkin" Cc: Christoph Hellwig Cc: Eric Dumazet Cc: Eric Van Hensbergen Cc: Takashi Iwai Cc: Vegard Nossum Cc: Dmitry Vyukov Cc: Marco Elver Cc: Andrey Konovalov Cc: Matthew Wilcox Cc: linux-mm@kvack.org --- This patch was previously known as "kmsan: unpoisoning buffers from devices etc.", but it turned out to be possible to drop most of the annotations from that patch, so it only relates to /dev/random now. Change-Id: Id460e7a86ce564f1357469f53d0c7410ca08f0e9 --- drivers/char/random.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/char/random.c b/drivers/char/random.c index 909e0c3d82ea..3c69b9772005 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -320,6 +320,7 @@ #include #include #include +#include #include #include #include @@ -1060,6 +1061,11 @@ static void _extract_crng(struct crng_state *crng, spin_lock_irqsave(&crng->lock, flags); if (arch_get_random_long(&v)) crng->state[14] ^= v; + /* + * Regardless of where the random data comes from, KMSAN should treat + * it as initialized. + */ + kmsan_unpoison_shadow(crng->state, sizeof(crng->state)); chacha20_block(&crng->state[0], out); if (crng->state[12] == 0) crng->state[13]++; -- 2.24.1.735.g03f4e72817-goog