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[23.128.96.18]) by mx.google.com with ESMTP id w6si8924104edd.217.2021.05.30.22.40.02; Sun, 30 May 2021 22:40:34 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=sDg+mggv; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 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 S230147AbhEaFkj (ORCPT + 99 others); Mon, 31 May 2021 01:40:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37888 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229730AbhEaFkf (ORCPT ); Mon, 31 May 2021 01:40:35 -0400 Received: from mail-ua1-x92d.google.com (mail-ua1-x92d.google.com [IPv6:2607:f8b0:4864:20::92d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DD8BAC061574; Sun, 30 May 2021 22:38:55 -0700 (PDT) Received: by mail-ua1-x92d.google.com with SMTP id n61so5989702uan.2; Sun, 30 May 2021 22:38:55 -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=HnNmmcpEGANCywXAOHjjcUJ4MN6oF/accismZD3OTBY=; b=sDg+mggvypKBneaa3Jrh6Gwlmjq7O+/sgTx9+ShU59xkd38JFVUcZUHTK7IdznJa/O T4wttBebcWUfBojLxSjIwj0o/xqvFZIApQZAIl0km6c8zpD1GXXbMNpmdOFYGDru2n0k d4F4SfkrQjZlJB+VoldJNtCi03dzZRr5YsWcvcFV6mak3lXgOnlIQnsTGcW+0PRiJQNw y5O0EaafidOdazuwmmhkblHGAQlKb1xYifEfQ8eH8Iv31D9YLqTB4Hb7Q9cKifR1Jvr7 J/9oi/Fnp2451KV631ZW3GZ7w98hE8V7KhPc8fN4ubxm5lYa6KyjM+WdsSSqrW7JbVdg 2kMw== 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=HnNmmcpEGANCywXAOHjjcUJ4MN6oF/accismZD3OTBY=; b=aKLnQUzgE3nMp2Sfb9zdgj7Fum5omwo8GBF7pMnfdC+mZ0tHkM+C8XMZ3Es4CiM7vc KLdscn12HyBTTFOimtvchjrVHvS5W1+PgK6VCaEUf9B+/aE4FrcB0Y1483FKnlgwBwpt hUp/ke827YMPdZrKLweUogoVHl1w2jbhtqdy7heC8e48D4+asD8r9mBGBAyTE7UVrVW9 6pMmfU/ds96SaD531rjlNpBFauzJkHwdzEBkN/C2fDDd5Q1RInXnpwo4FBkmB30Z/4Lm GPVNn3hV/GBGuidBgn/KrNrge/8ivnxrTR617sZtLHBZdQgkkURHBz9i8AHlJ4M9IzZ1 VTBQ== X-Gm-Message-State: AOAM533rlw9fE0+SIKh1hnz5xWE80DQ27VMyEygvb04KoN34Aplyp77W qhdtFywxisWHuudMvDhWxJP7bf1i+XZblm7YMfM= X-Received: by 2002:a1f:b488:: with SMTP id d130mr11690045vkf.17.1622439533937; Sun, 30 May 2021 22:38:53 -0700 (PDT) MIME-Version: 1.0 References: <20210531030550.1708816-1-yangyingliang@huawei.com> In-Reply-To: <20210531030550.1708816-1-yangyingliang@huawei.com> From: Hyunchul Lee Date: Mon, 31 May 2021 14:38:42 +0900 Message-ID: Subject: Re: [PATCH -next v2] 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-kernel@vger.kernel.org 2021=EB=85=84 5=EC=9B=94 31=EC=9D=BC (=EC=9B=94) =EC=98=A4=ED=9B=84 12:01, = Yang 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 > --- > v2: > Handle the case ksmbd_vfs_getcasexattr() returns 0. > --- > 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..2a9cc0bc7726 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 <=3D 0) { > ksmbd_err("not found stream in xattr : %zd\n", v_len); > - err =3D -ENOENT; > - return err; > + return v_len =3D=3D 0 ? -ENOENT : (int)v_len; How about making ksmbd_vfs_getcasexattr return -ENONENT instead of returning 0 to remove duplicate error handling code? Thanks, Hyunchul > } > > 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 <=3D 0) { > ksmbd_err("not found stream in xattr : %zd\n", v_len); > - err =3D -ENOENT; > + err =3D v_len =3D=3D 0 ? -ENOENT : (int)v_len; > goto out; > } > > -- > 2.25.1 >