From patchwork Mon Jan 25 15:30:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alessio Balsini X-Patchwork-Id: 12043641 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 246EDC433E0 for ; Mon, 25 Jan 2021 15:42:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D3475230FA for ; Mon, 25 Jan 2021 15:42:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730243AbhAYPmT (ORCPT ); Mon, 25 Jan 2021 10:42:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730207AbhAYPmB (ORCPT ); Mon, 25 Jan 2021 10:42:01 -0500 Received: from mail-wm1-x331.google.com (mail-wm1-x331.google.com [IPv6:2a00:1450:4864:20::331]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9FFC2C061A2D for ; Mon, 25 Jan 2021 07:31:10 -0800 (PST) Received: by mail-wm1-x331.google.com with SMTP id e15so11469716wme.0 for ; Mon, 25 Jan 2021 07:31:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=android.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=iwpIKZJEqgcyH9jTEkHY/oqU7zr1rLx1xK5r1q299wU=; b=M5mY7gcIWm30rHRLFfpJ6dVKIbqVpY567QMlr+38KgnT63CeaQnTw5jMWuzyX5Ue78 FXAAWtbuJX7k3a0w1/3gqITeZIjPn1WBnFrAhx3NF3sFhgiPs/rsah2Smt4Ux8jAMiMr OWJWrXDyfFjJOk+iCDJviGaBVc6zTTyQDdhTX5AYdNw9+j/AsKMiBXVUSuyHzt1k+PSe 4F66kv3CX8hEme1SqkXYXX2Oym13u8YKvbfDI9df8QdPYwxowcZG6VNKFhhdZniKNvRI xOM84w8hekDeXCS+otrcssbVpw8d3eH1Os42KAYdwVIYybE/T30cJKino7oY2KNHJg4h RBCg== 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=iwpIKZJEqgcyH9jTEkHY/oqU7zr1rLx1xK5r1q299wU=; b=NBcLXYM1dn/48h5/kbdJEENz9ikDowjqfSseRTsGtCAArlbC7VTkH43Po4f0ZDoqYs fegbCfO0EnqLxpPkqvCh4T+ZOjc9p30Gk97uYzIKYwdHtCIJMeeIMMaq85mZILtIpAHO heKv9czcUr6OhoJhofcSz6x4xKmdA7dlVCOcx49Ms1+PLPNvnagidSqYKB6H7KOjWUUo yFRhUzzdSKUn7u2Ut/NnCL8g4dyrOF2m4MxXYK/MMJzFxiYK3NvtSXEQ8NhvGCvQqrRz LwlsBklNYoWmVxE/NzKksxhWW38SiOKsl7jsWxwB8hMbsZOanoGSYu6AD2/xBCgtfqnR Lk1A== X-Gm-Message-State: AOAM5336CIDm0UZGY6BVn1Qi4AMHsyESomHfdVc2PqZWCd28sKlWQSFy HZSDbS8fZo+s8SQavTN/5hidRQ== X-Google-Smtp-Source: ABdhPJx3VC0jelypwqOAnjslGn7yu3b7OKbCzFWEs1qu6YAjEOp2s1YkzSYOzf11YVv3sUG7XqmzYg== X-Received: by 2002:a7b:ca4c:: with SMTP id m12mr638086wml.115.1611588669362; Mon, 25 Jan 2021 07:31:09 -0800 (PST) Received: from balsini.lon.corp.google.com ([2a00:79e0:d:210:4cd4:5994:40fe:253d]) by smtp.gmail.com with ESMTPSA id o14sm22611965wri.48.2021.01.25.07.31.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 25 Jan 2021 07:31:08 -0800 (PST) From: Alessio Balsini To: Miklos Szeredi Cc: Akilesh Kailash , Amir Goldstein , Antonio SJ Musumeci , David Anderson , Giuseppe Scrivano , Jann Horn , Jens Axboe , Martijn Coenen , Palmer Dabbelt , Paul Lawrence , Peng Tao , Stefano Duo , Zimuzo Ezeozue , wuyan , fuse-devel@lists.sourceforge.net, kernel-team@android.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH RESEND V12 2/8] fuse: 32-bit user space ioctl compat for fuse device Date: Mon, 25 Jan 2021 15:30:51 +0000 Message-Id: <20210125153057.3623715-3-balsini@android.com> X-Mailer: git-send-email 2.30.0.280.ga3ce27912f-goog In-Reply-To: <20210125153057.3623715-1-balsini@android.com> References: <20210125153057.3623715-1-balsini@android.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org With a 64-bit kernel build the FUSE device cannot handle ioctl requests coming from 32-bit user space. This is due to the ioctl command translation that generates different command identifiers that thus cannot be used for direct comparisons without proper manipulation. Explicitly extract type and number from the ioctl command to enable 32-bit user space compatibility on 64-bit kernel builds. Signed-off-by: Alessio Balsini --- fs/fuse/dev.c | 29 ++++++++++++++++++----------- include/uapi/linux/fuse.h | 3 ++- 2 files changed, 20 insertions(+), 12 deletions(-) diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 588f8d1240aa..ff9f3b83f879 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -2233,37 +2233,44 @@ static int fuse_device_clone(struct fuse_conn *fc, struct file *new) static long fuse_dev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { - int err = -ENOTTY; + int res; + int oldfd; + struct fuse_dev *fud = NULL; - if (cmd == FUSE_DEV_IOC_CLONE) { - int oldfd; + if (_IOC_TYPE(cmd) != FUSE_DEV_IOC_MAGIC) + return -EINVAL; - err = -EFAULT; - if (!get_user(oldfd, (__u32 __user *) arg)) { + switch (_IOC_NR(cmd)) { + case _IOC_NR(FUSE_DEV_IOC_CLONE): + res = -EFAULT; + if (!get_user(oldfd, (__u32 __user *)arg)) { struct file *old = fget(oldfd); - err = -EINVAL; + res = -EINVAL; if (old) { - struct fuse_dev *fud = NULL; - /* * Check against file->f_op because CUSE * uses the same ioctl handler. */ if (old->f_op == file->f_op && - old->f_cred->user_ns == file->f_cred->user_ns) + old->f_cred->user_ns == + file->f_cred->user_ns) fud = fuse_get_dev(old); if (fud) { mutex_lock(&fuse_mutex); - err = fuse_device_clone(fud->fc, file); + res = fuse_device_clone(fud->fc, file); mutex_unlock(&fuse_mutex); } fput(old); } } + break; + default: + res = -ENOTTY; + break; } - return err; + return res; } const struct file_operations fuse_dev_operations = { diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h index 98ca64d1beb6..54442612c48b 100644 --- a/include/uapi/linux/fuse.h +++ b/include/uapi/linux/fuse.h @@ -903,7 +903,8 @@ struct fuse_notify_retrieve_in { }; /* Device ioctls: */ -#define FUSE_DEV_IOC_CLONE _IOR(229, 0, uint32_t) +#define FUSE_DEV_IOC_MAGIC 229 +#define FUSE_DEV_IOC_CLONE _IOR(FUSE_DEV_IOC_MAGIC, 0, uint32_t) struct fuse_lseek_in { uint64_t fh;