From nobody Sun May 5 08:37:57 2024 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=gmail.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 164190327336358.827596609409284; Tue, 11 Jan 2022 04:14:33 -0800 (PST) Received: from localhost ([::1]:55056 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1n7G2q-0007k2-4N for importer@patchew.org; Tue, 11 Jan 2022 07:14:32 -0500 Received: from eggs.gnu.org ([209.51.188.92]:37904) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n7Fzg-00055A-SB; Tue, 11 Jan 2022 07:11:16 -0500 Received: from [2607:f8b0:4864:20::1036] (port=44987 helo=mail-pj1-x1036.google.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1n7FzZ-0004NI-6V; Tue, 11 Jan 2022 07:11:11 -0500 Received: by mail-pj1-x1036.google.com with SMTP id n30-20020a17090a5aa100b001b2b6509685so5472205pji.3; Tue, 11 Jan 2022 04:11:06 -0800 (PST) Received: from localhost.localdomain ([106.52.23.176]) by smtp.googlemail.com with ESMTPSA id oo14sm2553230pjb.34.2022.01.11.04.11.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 11 Jan 2022 04:11:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=jGbdQDYvE4v48Trz/6YmPH5c3vAOaZc9KqkCE+2SVRE=; b=oD+Z3B3RSuUyP/U8Z5rhFQmMrZ6Ti+pmvc2uN6W+4mhjCoVO7Fx3PqXXJj41QhDWdd 1X3l0aGyAeE31sRA4gWdC0B0stlVLZWC+qQGcp+sxZ6XvbwpZEEwWtwApr4sSZ3IkasS Y6+s6NWUeZFqofzo9o2GKhcIh0tSvOmmAZs2BmeE2XU+RZ2Vg3yV8PZnWXOH3K3LYnr4 bQbVJ0M7e+mel/uqXWeFQPZZSzKgbGYa+VPp2mPgZ+x5EMa5kZrTRsF4+XE6E6BCK7n4 5VZH/x6YzDM43//WXxVwxxVvW7hJx5r0l56Wo7vkq9/g5/3q4HGYXPr3aVm+ybptjVFb dpXQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=jGbdQDYvE4v48Trz/6YmPH5c3vAOaZc9KqkCE+2SVRE=; b=L+EquEPeOeeEKZkW0/tBvSEBQe1xbCUfLPQ0LWmw7rhC9EWw6RZqW3wziYXLTdZOWE 718F0qgtaDTo+E/5h08GoXD/aZG+yqI2+wJEd9GHREYw3CpCKJq02hfy/iOYuLS3zsCc RlINU+2JCIJ1coIPGnjAYI4mju1MtezFjeeOFKhMlJSEyDLeEXH/AYY11O2JVDvZiZue l3u8tZy8rx2XwV4xlsDTu+F2VOQB91yWQoSxsewR/LtOtAcmTcArKACfob+tMF9nIsq7 AJc0cB1QIDtpvukPRKrbToU8y3JPKAiBDYOpsFEKtIAFzubsT2DrOkzLnxsfq6yuobyI ayRg== X-Gm-Message-State: AOAM531gos1OluF6ZsTMEwsKAfPevl08IOBlaMYg4spke2bLR44uvQ0e OzFSUEpG+n50Spc5MdGXTNA= X-Google-Smtp-Source: ABdhPJy8176sV+AR6mJskaJYvLg5sdQfrxD3KP/pBlIMSieQsAK7fpCQ46uWXS+y3rFMgfX7X+Q6zg== X-Received: by 2002:a17:90b:3ecc:: with SMTP id rm12mr2748895pjb.225.1641903065943; Tue, 11 Jan 2022 04:11:05 -0800 (PST) From: Daniella Lee To: stefanha@redhat.com, fam@euphon.net, qemu-block@nongnu.org, qemu-devel@nongnu.org Subject: [PATCH] Fix null pointer dereference in util/fdmon-epoll.c Date: Tue, 11 Jan 2022 20:10:59 +0800 Message-Id: <20220111121059.3345034-1-daniellalee111@gmail.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Host-Lookup-Failed: Reverse DNS lookup failed for 2607:f8b0:4864:20::1036 (failed) Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2607:f8b0:4864:20::1036; envelope-from=daniellalee111@gmail.com; helo=mail-pj1-x1036.google.com X-Spam_score_int: -10 X-Spam_score: -1.1 X-Spam_bar: - X-Spam_report: (-1.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: daniellalee111@gmail.com, pai.po.sec@gmail.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZM-MESSAGEID: 1641903274465100001 Content-Type: text/plain; charset="utf-8" Orginal qemu commit hash: de3f5223fa4cf8bfc5e3fe1fd495ddf468edcdf7 In util/fdmon-epoll.c, function fdmon_epoll_update, variable "old_node"=20 maybe NULL with the condition, while it is directly used in the statement a= nd=20 may lead to null pointer dereferencen problem. Variable "r" in the condition is the return value of epoll_ctl function, and will return -1 when failed. Therefore, the patch added a check and initialized the variable "r". Signed-off-by: Daniella Lee --- util/fdmon-epoll.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/util/fdmon-epoll.c b/util/fdmon-epoll.c index e11a8a022e..3c8b0de694 100644 --- a/util/fdmon-epoll.c +++ b/util/fdmon-epoll.c @@ -38,10 +38,12 @@ static void fdmon_epoll_update(AioContext *ctx, .data.ptr =3D new_node, .events =3D new_node ? epoll_events_from_pfd(new_node->pfd.events)= : 0, }; - int r; + int r =3D -1; =20 if (!new_node) { - r =3D epoll_ctl(ctx->epollfd, EPOLL_CTL_DEL, old_node->pfd.fd, &ev= ent); + if (old_node) { + r =3D epoll_ctl(ctx->epollfd, EPOLL_CTL_DEL, old_node->pfd.fd,= &event); + } } else if (!old_node) { r =3D epoll_ctl(ctx->epollfd, EPOLL_CTL_ADD, new_node->pfd.fd, &ev= ent); } else { --=20 2.17.1