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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FSL_HELO_FAKE,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 6C69CC32753 for ; Wed, 14 Aug 2019 22:35:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3E2F0208C2 for ; Wed, 14 Aug 2019 22:35:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565822149; bh=l8Slk/c9NCmIURt4vJ515GO1o+OGPytEBQ6mmXfsoCc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=HYAG03MBVnpaFe3vUDt23he4QMwOBP4gZ4/2Z0phY3yMorjVyRfCNfejcsxQxLjnw iVOSnsRD4qXaScjM76/mZx8lEVkQCCKaM1aNMzIQQzDq/we3jgHJ+WAu/e2KvwcCa+ blYSbOXKTM7ZNlOjLrdPKBKr2maPLoUBKY63Y5+g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728864AbfHNWfr (ORCPT ); Wed, 14 Aug 2019 18:35:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:34600 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727217AbfHNWfq (ORCPT ); Wed, 14 Aug 2019 18:35:46 -0400 Received: from gmail.com (unknown [104.132.1.77]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 081B12064A; Wed, 14 Aug 2019 22:35:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565822145; bh=l8Slk/c9NCmIURt4vJ515GO1o+OGPytEBQ6mmXfsoCc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HZrWel2TOGlxa/OLzSgK6FZYkC9k5fmPXmA7SczQPr/nZXF5fhlrN12mEtzuphrKx naClhxqMHYFXy1R/MsRWN561L+U0nJMj+RQmokWi+/oM+CwhuEESn4oiXIYXhBuZnf 2ZHVbx8JH1SSewjdXfJj0RGtoca3cSvPVjunHj9Y= Date: Wed, 14 Aug 2019 15:35:43 -0700 From: Eric Biggers To: "Theodore Y. Ts'o" Cc: linux-fscrypt@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-crypto@vger.kernel.org, keyrings@vger.kernel.org, linux-api@vger.kernel.org, Satya Tangirala , Paul Crowley , Jaegeuk Kim Subject: Re: [PATCH v8 10/20] fscrypt: add FS_IOC_REMOVE_ENCRYPTION_KEY ioctl Message-ID: <20190814223542.GE101319@gmail.com> Mail-Followup-To: "Theodore Y. Ts'o" , linux-fscrypt@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-crypto@vger.kernel.org, keyrings@vger.kernel.org, linux-api@vger.kernel.org, Satya Tangirala , Paul Crowley , Jaegeuk Kim References: <20190805162521.90882-1-ebiggers@kernel.org> <20190805162521.90882-11-ebiggers@kernel.org> <20190813000644.GH28705@mit.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190813000644.GH28705@mit.edu> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On Mon, Aug 12, 2019 at 08:06:44PM -0400, Theodore Y. Ts'o wrote: > > + /* Some inodes still reference this key; try to evict them. */ > > + if (try_to_lock_encrypted_files(sb, mk) != 0) > > + status_flags |= > > + FSCRYPT_KEY_REMOVAL_STATUS_FLAG_FILES_BUSY; > > + } > > try_to_lock_encrypted_files() can return other errors besides -EBUSY; > in particular sync_filesystem() can return other errors, such as -EIO > or -EFSCORUPTED. In that case, I think we're better off returning the > relevant status code back to the user. We will have already wiped the > master key, but this situation will only happen in exceptional > conditions (e.g., user has ejected the sdcard, etc.), so it's not > worth it to try to undo the master key wipe to try to restore things > to the pre-ioctl execution state. > > So I think we should capture the return code from > try_to_lock_encrypted_files, and if it is EBUSY, we can set FILES_BUSY > flag and return success. Otherwise, we should return the error. > > If you agree, please fix that up and then feel free to add: > > Reviewed-by: Theodore Ts'o > > - Ted Yes, that makes sense. I've made the following change to this patch: diff --git a/fs/crypto/keyring.c b/fs/crypto/keyring.c index 9901593051424b..c3423f0edc7014 100644 --- a/fs/crypto/keyring.c +++ b/fs/crypto/keyring.c @@ -479,6 +479,7 @@ int fscrypt_ioctl_remove_key(struct file *filp, void __user *_uarg) struct key *key; struct fscrypt_master_key *mk; u32 status_flags = 0; + int err; bool dead; if (copy_from_user(&arg, uarg, sizeof(arg))) @@ -514,11 +515,15 @@ int fscrypt_ioctl_remove_key(struct file *filp, void __user *_uarg) * key object is free to be removed from the keyring. */ key_invalidate(key); + err = 0; } else { /* Some inodes still reference this key; try to evict them. */ - if (try_to_lock_encrypted_files(sb, mk) != 0) + err = try_to_lock_encrypted_files(sb, mk); + if (err == -EBUSY) { status_flags |= FSCRYPT_KEY_REMOVAL_STATUS_FLAG_FILES_BUSY; + err = 0; + } } /* * We return 0 if we successfully did something: wiped the secret, or @@ -527,7 +532,9 @@ int fscrypt_ioctl_remove_key(struct file *filp, void __user *_uarg) * including all files locked. */ key_put(key); - return put_user(status_flags, &uarg->removal_status_flags); + if (err == 0) + err = put_user(status_flags, &uarg->removal_status_flags); + return err; } EXPORT_SYMBOL_GPL(fscrypt_ioctl_remove_key);