From patchwork Wed Jul 24 03:49:26 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jia-Ju Bai X-Patchwork-Id: 11055655 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 38C991399 for ; Wed, 24 Jul 2019 03:49:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2991128774 for ; Wed, 24 Jul 2019 03:49:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1A8442877F; Wed, 24 Jul 2019 03:49:38 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BAEB328774 for ; Wed, 24 Jul 2019 03:49:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726425AbfGXDth (ORCPT ); Tue, 23 Jul 2019 23:49:37 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:38962 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726400AbfGXDtg (ORCPT ); Tue, 23 Jul 2019 23:49:36 -0400 Received: by mail-pg1-f194.google.com with SMTP id u17so20462993pgi.6; Tue, 23 Jul 2019 20:49:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=opj8lnCtN7uVcvkOiHNBMfsILzIZd7HuE+IB/qnbPFs=; b=ltVI7vA+iq01wgiVxnieomCY9v/Tub804FD/gn9yiUjeQMRw2XKJofb5kolEda7nrV v3aQUuQuzvKVF3jveZuBXMoNL+KrzVgCeDLCc8nV9CpqFCUMe6jmzNjNLGf0Khh2pywL sUBhtVnBipvGnWDKC5Yj0crLE61C0zJiSYLjdQ0NaUHBjpCZjuhqnxFDAtLHM91JULXM wQpQxztA9L2D5PGuXsf18W+CJ1pmRMx7lFizLIgDBdmO1w0lUJww65iQgnxFp0cgoJOk K9/XZXQLUrUg/4/AEXqlc24YDF/UFQoFD7z6oxdRGgSqnLksMjaeBMoS6Qzvb3Fr0yiW n/Hw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=opj8lnCtN7uVcvkOiHNBMfsILzIZd7HuE+IB/qnbPFs=; b=LgedTwpbgCJMGnuJAT/6zYcOQzy7dPGTn9zyYxYIQ8pdGqVZRdOEoAB4OPU7MvKkYb +obUgCQu7fIysX6YqX0gGA24XleiD/AkgtNJDSDDkKBRZ8FilRVx5S/iRbkRr59so+y9 HvTrd9J+WoEmVzgeSMDL/Tk5esjMzt4+IPo9r9yaPBGJl5HBYy6AfwVI3fIBI4fUm5go 5/JAGcXfovSRxFEuRFXRHxqhGrYGcQzHizZl2qT23PQLGmL9M9SqJmOaq5M6qFBGmJAw Q0rteVTpoXvk7XcmYmkyRnpLSSR4qieEvRui2yqv5JmTOm3wgTsEBNraUoOJqTk2HhpZ 8xAg== X-Gm-Message-State: APjAAAUDPTYmZ/qcecfCRn5OBiqzkD1tC6P499Fv2JqX23LsZM14xiWN wwlm5u5DG5iWTiDdCGfJWFg= X-Google-Smtp-Source: APXvYqyBkgnGLXPPn3Fmhpw5XGZNyK+qjPNJG9xfJlZpUy87glmS6K/MaU7Z+LJJOmGczl64Wayewg== X-Received: by 2002:a62:cdc8:: with SMTP id o191mr9130518pfg.74.1563940176347; Tue, 23 Jul 2019 20:49:36 -0700 (PDT) Received: from oslab.tsinghua.edu.cn ([2402:f000:4:72:808::3ca]) by smtp.gmail.com with ESMTPSA id t11sm51359610pgb.33.2019.07.23.20.49.34 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 23 Jul 2019 20:49:35 -0700 (PDT) From: Jia-Ju Bai To: philipp.reisner@linbit.com, lars.ellenberg@linbit.com, axboe@kernel.dk Cc: drbd-dev@lists.linbit.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH 2/2] block: drbd: Fix a possible null-pointer dereference in is_valid_state() Date: Wed, 24 Jul 2019 11:49:26 +0800 Message-Id: <20190724034926.28755-1-baijiaju1990@gmail.com> X-Mailer: git-send-email 2.17.0 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In is_valid_state(), there is an if statement on line 839 to check whether nc is NULL: if (nc) When nc is NULL, it is used on line 880: (nc->verify_alg[0] == 0) Thus, a possible null-pointer dereference may occur. To fix this bug, nc is also checked on line 880. This bug is found by a static analysis tool STCheck written by us. Signed-off-by: Jia-Ju Bai --- drivers/block/drbd/drbd_state.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c index eeaa3b49b264..3cf477e9cf6a 100644 --- a/drivers/block/drbd/drbd_state.c +++ b/drivers/block/drbd/drbd_state.c @@ -877,7 +877,7 @@ is_valid_state(struct drbd_device *device, union drbd_state ns) rv = SS_CONNECTED_OUTDATES; else if ((ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) && - (nc->verify_alg[0] == 0)) + (nc && nc->verify_alg[0] == 0)) rv = SS_NO_VERIFY_ALG; else if ((ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) &&