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=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 4D36BC4708E for ; Sat, 29 May 2021 14:13:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1CD0F61157 for ; Sat, 29 May 2021 14:13:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229716AbhE2OOv (ORCPT ); Sat, 29 May 2021 10:14:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60924 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229681AbhE2OOu (ORCPT ); Sat, 29 May 2021 10:14:50 -0400 Received: from mail-vs1-xe32.google.com (mail-vs1-xe32.google.com [IPv6:2607:f8b0:4864:20::e32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8D10FC061574; Sat, 29 May 2021 07:13:13 -0700 (PDT) Received: by mail-vs1-xe32.google.com with SMTP id f11so3702285vst.0; Sat, 29 May 2021 07:13:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=L2BlukILXONRQJcclTGh7GA2Qfr+L6d986kgRYUf/Ws=; b=lbrqNq0uEAew5n0pLs6zfKEUdjlz+WISW0Ok7SWpREczZQzFfAhbmhny6bTB9zwAR9 fiSbdsKRRPQ36nnRT2YDNiEmqVKU8H3/FTRSoLh1ALQSWYlgCgF+68e++RWnRnf6PNW3 39KuASfdF7zkxDJNi4xRvukcCrwStY3ywYwpQy1JORYO3flk+RiU/lr8jEL+wL7pez0K 8DuaekToFufi+g3pv+kWkfYBK1+hMgChZjsHv83z7PU+nsFijLZA71RN7Y5PjPFR8VEH m2Ajsw8T6rN+lESstwrTwxlUgjRwEhbIScO+d8JEzzruhK20IcYcf/6ANdD5WITI76Bp UDWg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=L2BlukILXONRQJcclTGh7GA2Qfr+L6d986kgRYUf/Ws=; b=uXo3JEMXSRi8zuKkph9U/zi5R1S51tZUohswF2iprU0TMcghH2BfOIZOTlekqR3vlc 3Mk26MxFWEwoFahw6oIApgXRyzBBsJITwNDveslsPtHoZ2i7ch+E9e3eJaVQ9R4jOyYm FpYzvQGUuDyveVFZptb/b24cZYtrzMXD/bUB/+vWFwsvCy7NwH/tnZksXzGL1Ih1vSun 0Ki33jGPfWh98dz1v5R8s3d2UVNCTAZpmry4Qie1ES1ZrreO8PM+s7bb2Y6vuKdn0G26 Dy1R8pp1yPDXdMn+wjQgW+wAaL+wrVnvTL7NfqcpCSMtV+MchKfog5QrNwn613jOcThg 3gmA== X-Gm-Message-State: AOAM532T3wn0gKVfH33+NRMjq4ntSZQPSo9NU6GiA+pFGPmgI74omR39 9scjqGCgBnLO7OgtirpZnppu8p0doZ2XI8JFg7I= X-Google-Smtp-Source: ABdhPJxDAViTVR8Z4Bq2yEXQKABk64nreqW75JIfEKNXn7UHMF8Ml1UzCfBPNAnEbTbvJ3u7GQBZnBmC8nA1Hnr1tb0= X-Received: by 2002:a67:d017:: with SMTP id r23mr10749055vsi.12.1622297592646; Sat, 29 May 2021 07:13:12 -0700 (PDT) MIME-Version: 1.0 References: <20210529082058.3012233-1-yangyingliang@huawei.com> <20210529082058.3012233-3-yangyingliang@huawei.com> In-Reply-To: <20210529082058.3012233-3-yangyingliang@huawei.com> From: Hyunchul Lee Date: Sat, 29 May 2021 23:13:01 +0900 Message-ID: Subject: Re: [PATCH -next 3/3] cifsd: check return value of ksmbd_vfs_getcasexattr() correctly To: Yang Yingliang Cc: LKML , linux-cifsd-devel , linux-cifs , Namjae Jeon , Sergey Senozhatsky , Steve French Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org Hi Yang, 2021=EB=85=84 5=EC=9B=94 29=EC=9D=BC (=ED=86=A0) =EC=98=A4=ED=9B=84 5:16, Y= ang Yingliang =EB=8B=98=EC=9D=B4 =EC=9E=91=EC=84= =B1: > > If ksmbd_vfs_getcasexattr() returns -ENOMEM, stream_buf is NULL, > it will cause null-ptr-deref when using it to copy memory. So we > need check the return value of ksmbd_vfs_getcasexattr() by comparing > with 0. > > Fixes: f44158485826 ("cifsd: add file operations") > Signed-off-by: Yang Yingliang > --- > fs/cifsd/vfs.c | 10 ++++------ > 1 file changed, 4 insertions(+), 6 deletions(-) > > diff --git a/fs/cifsd/vfs.c b/fs/cifsd/vfs.c > index 97d5584ec870..45ba30f1f2d2 100644 > --- a/fs/cifsd/vfs.c > +++ b/fs/cifsd/vfs.c > @@ -274,7 +274,6 @@ static int ksmbd_vfs_stream_read(struct ksmbd_file *f= p, char *buf, loff_t *pos, > { > ssize_t v_len; > char *stream_buf =3D NULL; > - int err; > > ksmbd_debug(VFS, "read stream data pos : %llu, count : %zd\n", > *pos, count); > @@ -283,10 +282,9 @@ static int ksmbd_vfs_stream_read(struct ksmbd_file *= fp, char *buf, loff_t *pos, > fp->stream.name, > fp->stream.size, > &stream_buf); > - if (v_len =3D=3D -ENOENT) { > + if ((int)v_len < 0) { because ksmbd_vfs_getcasexattr can return 0, 0 has to be handled. Thanks, Hyunchul > ksmbd_err("not found stream in xattr : %zd\n", v_len); > - err =3D -ENOENT; > - return err; > + return (int)v_len; > } > > memcpy(buf, &stream_buf[*pos], count); > @@ -415,9 +413,9 @@ static int ksmbd_vfs_stream_write(struct ksmbd_file *= fp, char *buf, loff_t *pos, > fp->stream.name, > fp->stream.size, > &stream_buf); > - if (v_len =3D=3D -ENOENT) { > + if ((int)v_len < 0) { > ksmbd_err("not found stream in xattr : %zd\n", v_len); > - err =3D -ENOENT; > + err =3D (int)v_len; > goto out; > } > > -- > 2.25.1 >