[PATCH 15/26] ubifs: Implement encrypt/decrypt for all IO

From: Richard Weinberger
Date: Fri Oct 21 2016 - 08:58:46 EST


Signed-off-by: Richard Weinberger <richard@xxxxxx>
---
fs/ubifs/file.c | 36 ++++++++++++++++++
fs/ubifs/journal.c | 105 +++++++++++++++++++++++++++++++++++++++++++----------
fs/ubifs/super.c | 6 ++-
fs/ubifs/ubifs.h | 6 +++
4 files changed, 131 insertions(+), 22 deletions(-)

diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index bd0049788e24..60e089d50c82 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -78,6 +78,24 @@ static int read_block(struct inode *inode, void *addr, unsigned int block,
goto dump;

dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
+
+ if (ubifs_crypt_is_encrypted(inode)) {
+ int clen = le16_to_cpu(dn->compr_size);
+
+ if (clen <= 0 || clen > UBIFS_BLOCK_SIZE || clen > dlen)
+ goto dump;
+
+ ubifs_assert(dlen <= UBIFS_BLOCK_SIZE);
+ err = fscrypt_decrypt_buffer(inode, &dn->data, &dn->data, dlen, block, GFP_NOFS);
+ if (err) {
+ ubifs_err(c, "fscrypt_decrypt_buffer failed: %i", err);
+ return err;
+ }
+
+ ubifs_assert(clen <= dlen);
+ dlen = clen;
+ }
+
out_len = UBIFS_BLOCK_SIZE;
err = ubifs_decompress(c, &dn->data, dlen, addr, &out_len,
le16_to_cpu(dn->compr_type));
@@ -650,6 +668,24 @@ static int populate_page(struct ubifs_info *c, struct page *page,

dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
out_len = UBIFS_BLOCK_SIZE;
+
+ if (ubifs_crypt_is_encrypted(inode)) {
+ int clen = le16_to_cpu(dn->compr_size);
+
+ if (clen <= 0 || clen > UBIFS_BLOCK_SIZE || clen > dlen)
+ goto out_err;
+
+ ubifs_assert(dlen <= UBIFS_BLOCK_SIZE);
+ err = fscrypt_decrypt_buffer(inode, &dn->data, &dn->data, dlen, page_block, GFP_NOFS);
+ if (err) {
+ ubifs_err(c, "fscrypt_decrypt_buffer failed: %i", err);
+ goto out_err;
+ }
+
+ ubifs_assert(clen <= dlen);
+ dlen = clen;
+ }
+
err = ubifs_decompress(c, &dn->data, dlen, addr, &out_len,
le16_to_cpu(dn->compr_type));
if (err || len != out_len)
diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c
index a643de4e3d91..da694e520ec8 100644
--- a/fs/ubifs/journal.c
+++ b/fs/ubifs/journal.c
@@ -691,11 +691,15 @@ int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode,
int err, lnum, offs, compr_type, out_len;
int dlen = COMPRESSED_DATA_NODE_BUF_SZ, allocated = 1;
struct ubifs_inode *ui = ubifs_inode(inode);
+ bool encrypted = ubifs_crypt_is_encrypted(inode);

dbg_jnlk(key, "ino %lu, blk %u, len %d, key ",
(unsigned long)key_inum(c, key), key_block(c, key), len);
ubifs_assert(len <= UBIFS_BLOCK_SIZE);

+ if (encrypted)
+ dlen += UBIFS_CIPHER_BLOCK_SIZE;
+
data = kmalloc(dlen, GFP_NOFS | __GFP_NOWARN);
if (!data) {
/*
@@ -724,6 +728,26 @@ int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode,
ubifs_compress(c, buf, len, &data->data, &out_len, &compr_type);
ubifs_assert(out_len <= UBIFS_BLOCK_SIZE);

+ if (encrypted) {
+ void *p = &data->data;
+ int plen = round_up(out_len, UBIFS_CIPHER_BLOCK_SIZE);
+
+ data->compr_size = cpu_to_le16(out_len);
+
+ if (plen != out_len) {
+ memset(p + out_len, 0, plen - out_len);
+ out_len = plen;
+ }
+
+ err = fscrypt_encrypt_buffer(inode, &data->data, &data->data, out_len, key_block(c, key), GFP_NOFS);
+ if (err) {
+ ubifs_err(c, "fscrypt_encrypt_buffer failed: %i", err);
+ goto out_free;
+ }
+ } else {
+ data->compr_size = 0;
+ }
+
dlen = UBIFS_DATA_NODE_SZ + out_len;
data->compr_type = cpu_to_le16(compr_type);

@@ -1083,31 +1107,79 @@ out_free:
}

/**
- * recomp_data_node - re-compress a truncated data node.
+ * truncate_data_node - re-compress/encrypt a truncated data node.
+ * @c: UBIFS file-system description object
+ * @inode: inode which referes to the data node
+ * @block: data block number
* @dn: data node to re-compress
* @new_len: new length
*
* This function is used when an inode is truncated and the last data node of
- * the inode has to be re-compressed and re-written.
+ * the inode has to be re-compressed/encrypted and re-written.
*/
-static int recomp_data_node(const struct ubifs_info *c,
- struct ubifs_data_node *dn, int *new_len)
+static int truncate_data_node(const struct ubifs_info *c, struct inode *inode,
+ unsigned int block, struct ubifs_data_node *dn,
+ int *new_len)
{
void *buf;
- int err, len, compr_type, out_len;
+ int err, dlen, compr_type, out_len, old_dlen;

out_len = le32_to_cpu(dn->size);
buf = kmalloc(out_len * WORST_COMPR_FACTOR, GFP_NOFS);
if (!buf)
return -ENOMEM;

- len = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
+ dlen = old_dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
compr_type = le16_to_cpu(dn->compr_type);
- err = ubifs_decompress(c, &dn->data, len, buf, &out_len, compr_type);
- if (err)
- goto out;

- ubifs_compress(c, buf, *new_len, &dn->data, &out_len, &compr_type);
+ if (ubifs_crypt_is_encrypted(inode)) {
+ int clen = le16_to_cpu(dn->compr_size);
+
+ if (clen <= 0 || clen > UBIFS_BLOCK_SIZE || clen > dlen) {
+ ubifs_err(c, "bad compr_size: %i", clen);
+ err = -EINVAL;
+ goto out;
+ }
+
+ err = fscrypt_decrypt_buffer(inode, &dn->data, &dn->data, dlen, block, GFP_NOFS);
+ if (err) {
+ ubifs_err(c, "fscrypt_decrypt_buffer failed: %i", err);
+ goto out;
+ }
+
+ ubifs_assert(clen <= dlen);
+ dlen = clen;
+ }
+
+ if (compr_type != UBIFS_COMPR_NONE) {
+ err = ubifs_decompress(c, &dn->data, dlen, buf, &out_len, compr_type);
+ if (err)
+ goto out;
+
+ ubifs_compress(c, buf, *new_len, &dn->data, &out_len, &compr_type);
+ }
+
+ if (ubifs_crypt_is_encrypted(inode)) {
+ void *p = &dn->data;
+ int plen = round_up(out_len, UBIFS_CIPHER_BLOCK_SIZE);
+
+ ubifs_assert(old_dlen >= plen);
+ dn->compr_size = cpu_to_le16(out_len);
+
+ if (plen != out_len) {
+ memset(p + out_len, 0, plen - out_len);
+ out_len = plen;
+ }
+
+ err = fscrypt_encrypt_buffer(inode, &dn->data, &dn->data, out_len, block, GFP_NOFS);
+ if (err) {
+ ubifs_msg(c, "fscrypt_encrypt_buffer failed: %i", err);
+ goto out;
+ }
+ } else {
+ dn->compr_size = 0;
+ }
+
ubifs_assert(out_len <= UBIFS_BLOCK_SIZE);
dn->compr_type = cpu_to_le16(compr_type);
dn->size = cpu_to_le32(*new_len);
@@ -1179,16 +1251,9 @@ int ubifs_jnl_truncate(struct ubifs_info *c, const struct inode *inode,
if (le32_to_cpu(dn->size) <= dlen)
dlen = 0; /* Nothing to do */
else {
- int compr_type = le16_to_cpu(dn->compr_type);
-
- if (compr_type != UBIFS_COMPR_NONE) {
- err = recomp_data_node(c, dn, &dlen);
- if (err)
- goto out_free;
- } else {
- dn->size = cpu_to_le32(dlen);
- dlen += UBIFS_DATA_NODE_SZ;
- }
+ err = truncate_data_node(c, inode, blk, dn, &dlen);
+ if (err)
+ goto out_free;
}
}
}
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index a31222947265..ae25c908fbe5 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1210,7 +1210,8 @@ static int mount_ubifs(struct ubifs_info *c)
bu_init(c);

if (!c->ro_mount) {
- c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ,
+ c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \
+ UBIFS_CIPHER_BLOCK_SIZE,
GFP_KERNEL);
if (!c->write_reserve_buf)
goto out_free;
@@ -1623,7 +1624,8 @@ static int ubifs_remount_rw(struct ubifs_info *c)
goto out;
}

- c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ, GFP_KERNEL);
+ c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \
+ UBIFS_CIPHER_BLOCK_SIZE, GFP_KERNEL);
if (!c->write_reserve_buf) {
err = -ENOMEM;
goto out;
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index 63dd027727ca..6c56a08afcd7 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -139,6 +139,12 @@
*/
#define WORST_COMPR_FACTOR 2

+#ifdef CONFIG_UBIFS_FS_ENCRYPTION
+#define UBIFS_CIPHER_BLOCK_SIZE FS_CRYPTO_BLOCK_SIZE
+#else
+#define UBIFS_CIPHER_BLOCK_SIZE 0
+#endif
+
/*
* How much memory is needed for a buffer where we compress a data node.
*/
--
2.7.3