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=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL autolearn=unavailable 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 EE1EDC32771 for ; Tue, 7 Jan 2020 02:33:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C57332072C for ; Tue, 7 Jan 2020 02:33:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="GX2yPf97" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727520AbgAGCdo (ORCPT ); Mon, 6 Jan 2020 21:33:44 -0500 Received: from mail-qv1-f73.google.com ([209.85.219.73]:39341 "EHLO mail-qv1-f73.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727479AbgAGCdo (ORCPT ); Mon, 6 Jan 2020 21:33:44 -0500 Received: by mail-qv1-f73.google.com with SMTP id e14so5648982qvr.6 for ; Mon, 06 Jan 2020 18:33:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=uDgGy4N5DtOaHRxIX87XlNisoWOld356Gqw2viQP+Cg=; b=GX2yPf97uYJ0DPsuAbjJiyRHt51aJEZzqcqZIcsevRT++LLQJUdvI4TYzJ5A7N8Pdv rLLSMt9pTbyQGc/KxO/MPhnl/ccD6LCaylu8LIXAvBaOSDEarCxs5antUNl6ob59pTxO /GK/LerdisX9BSTUZ8O7b/HDB0hK+bKFFr3tIzgUeWqKm+zeLtHbkrqtOfreCHOV77vk Ogid1uLmTo42YP3ImEMC3IkV9lG/iDuOZUPQytqPXodTv4dNbwRAoj0apAbQ3qyxkNh0 xr6LcOkLPvBwVdb+kIhbWCewiXoDB5iZl+w+xU8S+3P1d/eShQAj4m1M3VAYgaJT2AI6 h1Dw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=uDgGy4N5DtOaHRxIX87XlNisoWOld356Gqw2viQP+Cg=; b=LJTUqjn9WUrCQ/Fda+ejF7W6i9fKd4O5xD1b8BBE/PwZNp9OVZ+/Z/frMdRg4+W4vD utkH0FWw3N1X4bUGoZ6yYWxxNlgP+VLhQj0W8Z8BLnQY2GC1hVhdXIucoKx3tp774Vh0 Vl3A6MmJMCb3p6P2q7kI41FqUFlK9qRjTXbJVD4Z7SCtfrfdyAABa6IQbJ6PyP73D5UM 25r2ot+xrLKmJpVUcBDWA5K+ygFFUSMIVehcKp+BRpCBHmYKay4iD87QsCLXb8nR0MHk 6vUj8UvpWnAwiI69pdrBOtqu2vgwFe5zKOwnpP3eyhuDeNX+v11Ri+JdCMJ1L/MZyRD0 eM8w== X-Gm-Message-State: APjAAAW3LCyCmYVSNhR5O9xzLSSclYMuhcdiMCHPblErxwZsdVbdgeOr BWxcjM7L7ME/pXmw+39vQDqK4zQXLGM= X-Google-Smtp-Source: APXvYqxLQJi+pvRpSXTlckecgXNJr0DUPtu42xLMPCNoQAZRXqAYa9bgLpEC5ZxaN47fWYeCKLaDXCZan7Q= X-Received: by 2002:ac8:768d:: with SMTP id g13mr77460446qtr.7.1578364422392; Mon, 06 Jan 2020 18:33:42 -0800 (PST) Date: Mon, 6 Jan 2020 18:33:22 -0800 In-Reply-To: <20200107023323.38394-1-drosen@google.com> Message-Id: <20200107023323.38394-3-drosen@google.com> Mime-Version: 1.0 References: <20200107023323.38394-1-drosen@google.com> X-Mailer: git-send-email 2.24.1.735.g03f4e72817-goog Subject: [PATCH v2 2/3] fscrypt: Don't allow v1 policies with casefolding From: Daniel Rosenberg To: Eric Biggers , linux-fscrypt@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Gabriel Krisman Bertazi , kernel-team@android.com, Daniel Rosenberg Content-Type: text/plain; charset="UTF-8" Sender: linux-fscrypt-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org Casefolding currently requires a derived key for computing the siphash. This is available for v2 policies, but not v1, so we disallow it for v1. Signed-off-by: Daniel Rosenberg --- fs/crypto/keysetup.c | 7 ++++--- fs/crypto/policy.c | 39 +++++++++++++++++++++++++++++++++++++++ fs/inode.c | 7 +++++++ include/linux/fscrypt.h | 11 +++++++++++ 4 files changed, 61 insertions(+), 3 deletions(-) diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c index c1bd897c9310..7445ab76e0b3 100644 --- a/fs/crypto/keysetup.c +++ b/fs/crypto/keysetup.c @@ -224,10 +224,11 @@ static int fscrypt_setup_v2_file_key(struct fscrypt_info *ci, FS_KEY_DERIVATION_NONCE_SIZE, (u8 *)&ci->ci_hash_key, sizeof(ci->ci_hash_key)); - if (!err) - ci->ci_hash_key_initialized = true; + if (err) + return err; + ci->ci_hash_key_initialized = true; } - return err; + return 0; } /* diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c index f1cff83c151a..9e937cfa732c 100644 --- a/fs/crypto/policy.c +++ b/fs/crypto/policy.c @@ -124,6 +124,12 @@ static bool fscrypt_supported_v1_policy(const struct fscrypt_policy_v1 *policy, policy->filenames_encryption_mode)) return false; + if (IS_CASEFOLDED(inode)) { + fscrypt_warn(inode, + "v1 policy does not support casefolded directories"); + return false; + } + return true; } @@ -579,3 +585,36 @@ int fscrypt_inherit_context(struct inode *parent, struct inode *child, return preload ? fscrypt_get_encryption_info(child): 0; } EXPORT_SYMBOL(fscrypt_inherit_context); + +static int fscrypt_set_casefolding_allowed(struct inode *inode) +{ + union fscrypt_policy policy; + int err = fscrypt_get_policy(inode, &policy); + + if (err) + return err; + + if (policy.version != FSCRYPT_POLICY_V2) + return -EINVAL; + + return 0; +} + +int fscrypt_ioc_setflags_prepare(struct inode *inode, + unsigned int oldflags, + unsigned int flags) +{ + int err; + + /* + * When a directory is encrypted, the CASEFOLD flag can only be turned + * on if the fscrypt policy supports it. + */ + if (IS_ENCRYPTED(inode) && (flags & ~oldflags & FS_CASEFOLD_FL)) { + err = fscrypt_set_casefolding_allowed(inode); + if (err) + return err; + } + + return 0; +} diff --git a/fs/inode.c b/fs/inode.c index 96d62d97694e..77f3e6e2e934 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include "internal.h" @@ -2242,6 +2243,8 @@ EXPORT_SYMBOL(current_time); int vfs_ioc_setflags_prepare(struct inode *inode, unsigned int oldflags, unsigned int flags) { + int err; + /* * The IMMUTABLE and APPEND_ONLY flags can only be changed by * the relevant capability. @@ -2252,6 +2255,10 @@ int vfs_ioc_setflags_prepare(struct inode *inode, unsigned int oldflags, !capable(CAP_LINUX_IMMUTABLE)) return -EPERM; + err = fscrypt_ioc_setflags_prepare(inode, oldflags, flags); + if (err) + return err; + return 0; } EXPORT_SYMBOL(vfs_ioc_setflags_prepare); diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index 1dfbed855bee..2c292f19c6b9 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -142,6 +142,10 @@ extern int fscrypt_ioctl_get_policy_ex(struct file *, void __user *); extern int fscrypt_has_permitted_context(struct inode *, struct inode *); extern int fscrypt_inherit_context(struct inode *, struct inode *, void *, bool); +extern int fscrypt_ioc_setflags_prepare(struct inode *inode, + unsigned int oldflags, + unsigned int flags); + /* keyring.c */ extern void fscrypt_sb_free(struct super_block *sb); extern int fscrypt_ioctl_add_key(struct file *filp, void __user *arg); @@ -383,6 +387,13 @@ static inline int fscrypt_inherit_context(struct inode *parent, return -EOPNOTSUPP; } +static inline int fscrypt_ioc_setflags_prepare(struct inode *inode, + unsigned int oldflags, + unsigned int flags) +{ + return 0; +} + /* keyring.c */ static inline void fscrypt_sb_free(struct super_block *sb) { -- 2.24.1.735.g03f4e72817-goog