From 8d08dab786ad5cc2aca2bf870de370144b78c85a Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Tue, 17 May 2011 00:50:33 -0500 Subject: [PATCH] eCryptfs: Allow 2 scatterlist entries for encrypted filenames 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 Cc: --- 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 03e609c45012..27a7fefb83eb 100644 --- a/fs/ecryptfs/keystore.c +++ b/fs/ecryptfs/keystore.c @@ -599,8 +599,8 @@ 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]; @@ -816,23 +816,21 @@ 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 @@ -855,7 +853,7 @@ 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; " @@ -891,8 +889,8 @@ 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]; @@ -1008,13 +1006,12 @@ 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; @@ -1028,13 +1025,12 @@ 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 @@ -1065,7 +1061,7 @@ 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; " -- 2.34.1