From patchwork Mon Aug 24 06:17:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 11732209 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A0F2B1392 for ; Mon, 24 Aug 2020 06:18:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 88EEF22B3F for ; Mon, 24 Aug 2020 06:18:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598249922; bh=FIdPAQ4uVgqepfVvwpPtlAMJGJ/BCwZf2dDwk5M0shA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=RVG7RJb+7WIQalfLgndb12B+Y9Dy3sFCWVQ4fpgdFjFgnpZ3cbAwuEpyr+LF0nvMU NK7PYvNtYA+WHMMEQ1JOR/T8P/Oztjv5HcCX2i7TmNP72LuvktOq3+k4jF7KYZ34Wz nBaxpFiqrPf1LK+zR8GlzA+pn29UvyryWYHttCwQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725730AbgHXGSj (ORCPT ); Mon, 24 Aug 2020 02:18:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:49986 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726075AbgHXGS2 (ORCPT ); Mon, 24 Aug 2020 02:18:28 -0400 Received: from sol.hsd1.ca.comcast.net (c-107-3-166-239.hsd1.ca.comcast.net [107.3.166.239]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9733422BEA; Mon, 24 Aug 2020 06:18:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598249900; bh=FIdPAQ4uVgqepfVvwpPtlAMJGJ/BCwZf2dDwk5M0shA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aOFOzAVN6aex+LS5Y2deYUb9Qjxp+H46wBD4Q4HDvUhaKg92JKU/CLVURb4LyzBUw 2+WvbtU7sO6GQxDGsaEnuYSknW0lS3fpbkqF4Evz/SyGisvOuCd6oEkWg/7aYH/ioI 8+eqiG/nQFxpH2RSz/7EstoUxgliPnfNi17KeKtQ= From: Eric Biggers To: linux-fscrypt@vger.kernel.org Cc: linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org, ceph-devel@vger.kernel.org, Jeff Layton Subject: [RFC PATCH 8/8] fscrypt: stop pretending that key setup is nofs-safe Date: Sun, 23 Aug 2020 23:17:12 -0700 Message-Id: <20200824061712.195654-9-ebiggers@kernel.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200824061712.195654-1-ebiggers@kernel.org> References: <20200824061712.195654-1-ebiggers@kernel.org> MIME-Version: 1.0 Sender: ceph-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org From: Eric Biggers fscrypt_get_encryption_info() has never actually been safe to call in a context that needs GFP_NOFS, since it calls crypto_alloc_skcipher(). crypto_alloc_skcipher() isn't GFP_NOFS-safe, even if called under memalloc_nofs_save(). This is because it may load kernel modules, and also because it internally takes crypto_alg_sem. Other tasks can do GFP_KERNEL allocations while holding crypto_alg_sem for write. The use of fscrypt_init_mutex isn't GFP_NOFS-safe either. So, stop pretending that fscrypt_get_encryption_info() is nofs-safe. I.e., when it allocates memory, just use GFP_KERNEL instead of GFP_NOFS. Note, another reason to do this is that GFP_NOFS is deprecated in favor of using memalloc_nofs_save() in the proper places. Signed-off-by: Eric Biggers --- fs/crypto/inline_crypt.c | 7 ++----- fs/crypto/keysetup.c | 2 +- fs/crypto/keysetup_v1.c | 8 ++++---- 3 files changed, 7 insertions(+), 10 deletions(-) diff --git a/fs/crypto/inline_crypt.c b/fs/crypto/inline_crypt.c index faa25541ccb68..89bffa82ed74a 100644 --- a/fs/crypto/inline_crypt.c +++ b/fs/crypto/inline_crypt.c @@ -106,7 +106,7 @@ int fscrypt_select_encryption_impl(struct fscrypt_info *ci) crypto_cfg.data_unit_size = sb->s_blocksize; crypto_cfg.dun_bytes = fscrypt_get_dun_bytes(ci); num_devs = fscrypt_get_num_devices(sb); - devs = kmalloc_array(num_devs, sizeof(*devs), GFP_NOFS); + devs = kmalloc_array(num_devs, sizeof(*devs), GFP_KERNEL); if (!devs) return -ENOMEM; fscrypt_get_devices(sb, num_devs, devs); @@ -135,9 +135,8 @@ int fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key, struct fscrypt_blk_crypto_key *blk_key; int err; int i; - unsigned int flags; - blk_key = kzalloc(struct_size(blk_key, devs, num_devs), GFP_NOFS); + blk_key = kzalloc(struct_size(blk_key, devs, num_devs), GFP_KERNEL); if (!blk_key) return -ENOMEM; @@ -166,10 +165,8 @@ int fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key, } queue_refs++; - flags = memalloc_nofs_save(); err = blk_crypto_start_using_key(&blk_key->base, blk_key->devs[i]); - memalloc_nofs_restore(flags); if (err) { fscrypt_err(inode, "error %d starting to use blk-crypto", err); diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c index 6ac816d3e8478..ad64525ec6800 100644 --- a/fs/crypto/keysetup.c +++ b/fs/crypto/keysetup.c @@ -477,7 +477,7 @@ fscrypt_setup_encryption_info(struct inode *inode, struct key *master_key = NULL; int res; - crypt_info = kmem_cache_zalloc(fscrypt_info_cachep, GFP_NOFS); + crypt_info = kmem_cache_zalloc(fscrypt_info_cachep, GFP_KERNEL); if (!crypt_info) return -ENOMEM; diff --git a/fs/crypto/keysetup_v1.c b/fs/crypto/keysetup_v1.c index a3cb52572b05c..2762c53504323 100644 --- a/fs/crypto/keysetup_v1.c +++ b/fs/crypto/keysetup_v1.c @@ -60,7 +60,7 @@ static int derive_key_aes(const u8 *master_key, goto out; } crypto_skcipher_set_flags(tfm, CRYPTO_TFM_REQ_FORBID_WEAK_KEYS); - req = skcipher_request_alloc(tfm, GFP_NOFS); + req = skcipher_request_alloc(tfm, GFP_KERNEL); if (!req) { res = -ENOMEM; goto out; @@ -99,7 +99,7 @@ find_and_lock_process_key(const char *prefix, const struct user_key_payload *ukp; const struct fscrypt_key *payload; - description = kasprintf(GFP_NOFS, "%s%*phN", prefix, + description = kasprintf(GFP_KERNEL, "%s%*phN", prefix, FSCRYPT_KEY_DESCRIPTOR_SIZE, descriptor); if (!description) return ERR_PTR(-ENOMEM); @@ -228,7 +228,7 @@ fscrypt_get_direct_key(const struct fscrypt_info *ci, const u8 *raw_key) return dk; /* Nope, allocate one. */ - dk = kzalloc(sizeof(*dk), GFP_NOFS); + dk = kzalloc(sizeof(*dk), GFP_KERNEL); if (!dk) return ERR_PTR(-ENOMEM); refcount_set(&dk->dk_refcount, 1); @@ -272,7 +272,7 @@ static int setup_v1_file_key_derived(struct fscrypt_info *ci, * This cannot be a stack buffer because it will be passed to the * scatterlist crypto API during derive_key_aes(). */ - derived_key = kmalloc(ci->ci_mode->keysize, GFP_NOFS); + derived_key = kmalloc(ci->ci_mode->keysize, GFP_KERNEL); if (!derived_key) return -ENOMEM;