Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965407Ab2EOCRz (ORCPT ); Mon, 14 May 2012 22:17:55 -0400 Received: from mail.windriver.com ([147.11.1.11]:49177 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964890Ab2EOCQ0 (ORCPT ); Mon, 14 May 2012 22:16:26 -0400 From: Paul Gortmaker To: , Subject: [34-longterm 033/179] eCryptfs: Allow 2 scatterlist entries for encrypted filenames Date: Mon, 14 May 2012 22:12:09 -0400 Message-ID: <1337048075-6132-34-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.9.6 In-Reply-To: <1337048075-6132-1-git-send-email-paul.gortmaker@windriver.com> References: <1337048075-6132-1-git-send-email-paul.gortmaker@windriver.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6472 Lines: 152 From: Tyler Hicks ------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. ------------------- commit 8d08dab786ad5cc2aca2bf870de370144b78c85a upstream. The buffers allocated while encrypting and decrypting long filenames can sometimes straddle two pages. In this situation, virt_to_scatterlist() will return -ENOMEM, causing the operation to fail and the user will get scary error messages in their logs: kernel: ecryptfs_write_tag_70_packet: Internal error whilst attempting to convert filename memory to scatterlist; expected rc = 1; got rc = [-12]. block_aligned_filename_size = [272] kernel: ecryptfs_encrypt_filename: Error attempting to generate tag 70 packet; rc = [-12] kernel: ecryptfs_encrypt_and_encode_filename: Error attempting to encrypt filename; rc = [-12] kernel: ecryptfs_lookup: Error attempting to encrypt and encode filename; rc = [-12] The solution is to allow up to 2 scatterlist entries to be used. Signed-off-by: Tyler Hicks Signed-off-by: Paul Gortmaker --- fs/ecryptfs/keystore.c | 46 +++++++++++++++++++++------------------------- 1 file changed, 21 insertions(+), 25 deletions(-) diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c index d6e9355..07f23c5 100644 --- a/fs/ecryptfs/keystore.c +++ b/fs/ecryptfs/keystore.c @@ -482,8 +482,8 @@ struct ecryptfs_write_tag_70_packet_silly_stack { struct mutex *tfm_mutex; char *block_aligned_filename; struct ecryptfs_auth_tok *auth_tok; - struct scatterlist src_sg; - struct scatterlist dst_sg; + struct scatterlist src_sg[2]; + struct scatterlist dst_sg[2]; struct blkcipher_desc desc; char iv[ECRYPTFS_MAX_IV_BYTES]; char hash[ECRYPTFS_TAG_70_DIGEST_SIZE]; @@ -696,23 +696,21 @@ ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes, memcpy(&s->block_aligned_filename[s->num_rand_bytes], filename, filename_size); rc = virt_to_scatterlist(s->block_aligned_filename, - s->block_aligned_filename_size, &s->src_sg, 1); - if (rc != 1) { + s->block_aligned_filename_size, s->src_sg, 2); + if (rc < 1) { printk(KERN_ERR "%s: Internal error whilst attempting to " - "convert filename memory to scatterlist; " - "expected rc = 1; got rc = [%d]. " + "convert filename memory to scatterlist; rc = [%d]. " "block_aligned_filename_size = [%zd]\n", __func__, rc, s->block_aligned_filename_size); goto out_release_free_unlock; } rc = virt_to_scatterlist(&dest[s->i], s->block_aligned_filename_size, - &s->dst_sg, 1); - if (rc != 1) { + s->dst_sg, 2); + if (rc < 1) { printk(KERN_ERR "%s: Internal error whilst attempting to " "convert encrypted filename memory to scatterlist; " - "expected rc = 1; got rc = [%d]. " - "block_aligned_filename_size = [%zd]\n", __func__, rc, - s->block_aligned_filename_size); + "rc = [%d]. block_aligned_filename_size = [%zd]\n", + __func__, rc, s->block_aligned_filename_size); goto out_release_free_unlock; } /* The characters in the first block effectively do the job @@ -735,7 +733,7 @@ ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes, mount_crypt_stat->global_default_fn_cipher_key_bytes); goto out_release_free_unlock; } - rc = crypto_blkcipher_encrypt_iv(&s->desc, &s->dst_sg, &s->src_sg, + rc = crypto_blkcipher_encrypt_iv(&s->desc, s->dst_sg, s->src_sg, s->block_aligned_filename_size); if (rc) { printk(KERN_ERR "%s: Error attempting to encrypt filename; " @@ -767,8 +765,8 @@ struct ecryptfs_parse_tag_70_packet_silly_stack { struct mutex *tfm_mutex; char *decrypted_filename; struct ecryptfs_auth_tok *auth_tok; - struct scatterlist src_sg; - struct scatterlist dst_sg; + struct scatterlist src_sg[2]; + struct scatterlist dst_sg[2]; struct blkcipher_desc desc; char fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX + 1]; char iv[ECRYPTFS_MAX_IV_BYTES]; @@ -873,13 +871,12 @@ ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size, } mutex_lock(s->tfm_mutex); rc = virt_to_scatterlist(&data[(*packet_size)], - s->block_aligned_filename_size, &s->src_sg, 1); - if (rc != 1) { + s->block_aligned_filename_size, s->src_sg, 2); + if (rc < 1) { printk(KERN_ERR "%s: Internal error whilst attempting to " "convert encrypted filename memory to scatterlist; " - "expected rc = 1; got rc = [%d]. " - "block_aligned_filename_size = [%zd]\n", __func__, rc, - s->block_aligned_filename_size); + "rc = [%d]. block_aligned_filename_size = [%zd]\n", + __func__, rc, s->block_aligned_filename_size); goto out_unlock; } (*packet_size) += s->block_aligned_filename_size; @@ -893,13 +890,12 @@ ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size, goto out_unlock; } rc = virt_to_scatterlist(s->decrypted_filename, - s->block_aligned_filename_size, &s->dst_sg, 1); - if (rc != 1) { + s->block_aligned_filename_size, s->dst_sg, 2); + if (rc < 1) { printk(KERN_ERR "%s: Internal error whilst attempting to " "convert decrypted filename memory to scatterlist; " - "expected rc = 1; got rc = [%d]. " - "block_aligned_filename_size = [%zd]\n", __func__, rc, - s->block_aligned_filename_size); + "rc = [%d]. block_aligned_filename_size = [%zd]\n", + __func__, rc, s->block_aligned_filename_size); goto out_free_unlock; } /* The characters in the first block effectively do the job of @@ -938,7 +934,7 @@ ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size, mount_crypt_stat->global_default_fn_cipher_key_bytes); goto out_free_unlock; } - rc = crypto_blkcipher_decrypt_iv(&s->desc, &s->dst_sg, &s->src_sg, + rc = crypto_blkcipher_decrypt_iv(&s->desc, s->dst_sg, s->src_sg, s->block_aligned_filename_size); if (rc) { printk(KERN_ERR "%s: Error attempting to decrypt filename; " -- 1.7.9.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/