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firmware/br-ext-chip-allwinner/board/v83x/kernel/patches/00000-fs_crypto_fname.c.patch

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diff -drupN a/fs/crypto/fname.c b/fs/crypto/fname.c
--- a/fs/crypto/fname.c 2018-08-06 17:23:04.000000000 +0300
+++ b/fs/crypto/fname.c 2022-06-12 05:28:14.000000000 +0300
@@ -12,57 +12,46 @@
#include <linux/scatterlist.h>
#include <linux/ratelimit.h>
-#include <linux/fscrypto.h>
+#include <crypto/skcipher.h>
+#include "fscrypt_private.h"
-/**
- * fname_crypt_complete() - completion callback for filename crypto
- * @req: The asynchronous cipher request context
- * @res: The result of the cipher operation
- */
-static void fname_crypt_complete(struct crypto_async_request *req, int res)
+static inline bool fscrypt_is_dot_dotdot(const struct qstr *str)
{
- struct fscrypt_completion_result *ecr = req->data;
+ if (str->len == 1 && str->name[0] == '.')
+ return true;
- if (res == -EINPROGRESS)
- return;
- ecr->res = res;
- complete(&ecr->completion);
+ if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
+ return true;
+
+ return false;
}
/**
* fname_encrypt() - encrypt a filename
*
- * The caller must have allocated sufficient memory for the @oname string.
+ * The output buffer must be at least as large as the input buffer.
+ * Any extra space is filled with NUL padding before encryption.
*
* Return: 0 on success, -errno on failure
*/
-static int fname_encrypt(struct inode *inode,
- const struct qstr *iname, struct fscrypt_str *oname)
+int fname_encrypt(struct inode *inode, const struct qstr *iname,
+ u8 *out, unsigned int olen)
{
struct skcipher_request *req = NULL;
- DECLARE_FS_COMPLETION_RESULT(ecr);
- struct fscrypt_info *ci = inode->i_crypt_info;
- struct crypto_skcipher *tfm = ci->ci_ctfm;
+ DECLARE_CRYPTO_WAIT(wait);
+ struct crypto_skcipher *tfm = inode->i_crypt_info->ci_ctfm;
int res = 0;
char iv[FS_CRYPTO_BLOCK_SIZE];
struct scatterlist sg;
- int padding = 4 << (ci->ci_flags & FS_POLICY_FLAGS_PAD_MASK);
- unsigned int lim;
- unsigned int cryptlen;
-
- lim = inode->i_sb->s_cop->max_namelen(inode);
- if (iname->len <= 0 || iname->len > lim)
- return -EIO;
/*
* Copy the filename to the output buffer for encrypting in-place and
* pad it with the needed number of NUL bytes.
*/
- cryptlen = max_t(unsigned int, iname->len, FS_CRYPTO_BLOCK_SIZE);
- cryptlen = round_up(cryptlen, padding);
- cryptlen = min(cryptlen, lim);
- memcpy(oname->name, iname->name, iname->len);
- memset(oname->name + iname->len, 0, cryptlen - iname->len);
+ if (WARN_ON(olen < iname->len))
+ return -ENOBUFS;
+ memcpy(out, iname->name, iname->len);
+ memset(out + iname->len, 0, olen - iname->len);
/* Initialize the IV */
memset(iv, 0, FS_CRYPTO_BLOCK_SIZE);
@@ -76,17 +65,12 @@ static int fname_encrypt(struct inode *i
}
skcipher_request_set_callback(req,
CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
- fname_crypt_complete, &ecr);
- sg_init_one(&sg, oname->name, cryptlen);
- skcipher_request_set_crypt(req, &sg, &sg, cryptlen, iv);
+ crypto_req_done, &wait);
+ sg_init_one(&sg, out, olen);
+ skcipher_request_set_crypt(req, &sg, &sg, olen, iv);
/* Do the encryption */
- res = crypto_skcipher_encrypt(req);
- if (res == -EINPROGRESS || res == -EBUSY) {
- /* Request is being completed asynchronously; wait for it */
- wait_for_completion(&ecr.completion);
- res = ecr.res;
- }
+ res = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
skcipher_request_free(req);
if (res < 0) {
printk_ratelimited(KERN_ERR
@@ -94,7 +78,6 @@ static int fname_encrypt(struct inode *i
return res;
}
- oname->len = cryptlen;
return 0;
}
@@ -110,7 +93,7 @@ static int fname_decrypt(struct inode *i
struct fscrypt_str *oname)
{
struct skcipher_request *req = NULL;
- DECLARE_FS_COMPLETION_RESULT(ecr);
+ DECLARE_CRYPTO_WAIT(wait);
struct scatterlist src_sg, dst_sg;
struct fscrypt_info *ci = inode->i_crypt_info;
struct crypto_skcipher *tfm = ci->ci_ctfm;
@@ -131,7 +114,7 @@ static int fname_decrypt(struct inode *i
}
skcipher_request_set_callback(req,
CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
- fname_crypt_complete, &ecr);
+ crypto_req_done, &wait);
/* Initialize IV */
memset(iv, 0, FS_CRYPTO_BLOCK_SIZE);
@@ -140,11 +123,7 @@ static int fname_decrypt(struct inode *i
sg_init_one(&src_sg, iname->name, iname->len);
sg_init_one(&dst_sg, oname->name, oname->len);
skcipher_request_set_crypt(req, &src_sg, &dst_sg, iname->len, iv);
- res = crypto_skcipher_decrypt(req);
- if (res == -EINPROGRESS || res == -EBUSY) {
- wait_for_completion(&ecr.completion);
- res = ecr.res;
- }
+ res = crypto_wait_req(crypto_skcipher_decrypt(req), &wait);
skcipher_request_free(req);
if (res < 0) {
printk_ratelimited(KERN_ERR
@@ -159,6 +138,8 @@ static int fname_decrypt(struct inode *i
static const char *lookup_table =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+,";
+#define BASE64_CHARS(nbytes) DIV_ROUND_UP((nbytes) * 4, 3)
+
/**
* digest_encode() -
*
@@ -209,47 +190,52 @@ static int digest_decode(const char *src
return cp - dst;
}
-u32 fscrypt_fname_encrypted_size(struct inode *inode, u32 ilen)
+bool fscrypt_fname_encrypted_size(const struct inode *inode, u32 orig_len,
+ u32 max_len, u32 *encrypted_len_ret)
{
- int padding = 32;
- struct fscrypt_info *ci = inode->i_crypt_info;
+ int padding = 4 << (inode->i_crypt_info->ci_flags &
+ FS_POLICY_FLAGS_PAD_MASK);
+ u32 encrypted_len;
- if (ci)
- padding = 4 << (ci->ci_flags & FS_POLICY_FLAGS_PAD_MASK);
- ilen = max(ilen, (u32)FS_CRYPTO_BLOCK_SIZE);
- return round_up(ilen, padding);
+ if (orig_len > max_len)
+ return false;
+ encrypted_len = max(orig_len, (u32)FS_CRYPTO_BLOCK_SIZE);
+ encrypted_len = round_up(encrypted_len, padding);
+ *encrypted_len_ret = min(encrypted_len, max_len);
+ return true;
}
-EXPORT_SYMBOL(fscrypt_fname_encrypted_size);
/**
- * fscrypt_fname_crypto_alloc_obuff() -
+ * fscrypt_fname_alloc_buffer - allocate a buffer for presented filenames
*
- * Allocates an output buffer that is sufficient for the crypto operation
- * specified by the context and the direction.
+ * Allocate a buffer that is large enough to hold any decrypted or encoded
+ * filename (null-terminated), for the given maximum encrypted filename length.
+ *
+ * Return: 0 on success, -errno on failure
*/
-int fscrypt_fname_alloc_buffer(struct inode *inode,
- u32 ilen, struct fscrypt_str *crypto_str)
+int fscrypt_fname_alloc_buffer(const struct inode *inode,
+ u32 max_encrypted_len,
+ struct fscrypt_str *crypto_str)
{
- unsigned int olen = fscrypt_fname_encrypted_size(inode, ilen);
+ const u32 max_encoded_len =
+ max_t(u32, BASE64_CHARS(FSCRYPT_FNAME_MAX_UNDIGESTED_SIZE),
+ 1 + BASE64_CHARS(sizeof(struct fscrypt_digested_name)));
+ u32 max_presented_len;
- crypto_str->len = olen;
- if (olen < FS_FNAME_CRYPTO_DIGEST_SIZE * 2)
- olen = FS_FNAME_CRYPTO_DIGEST_SIZE * 2;
- /*
- * Allocated buffer can hold one more character to null-terminate the
- * string
- */
- crypto_str->name = kmalloc(olen + 1, GFP_NOFS);
- if (!(crypto_str->name))
+ max_presented_len = max(max_encoded_len, max_encrypted_len);
+
+ crypto_str->name = kmalloc(max_presented_len + 1, GFP_NOFS);
+ if (!crypto_str->name)
return -ENOMEM;
+ crypto_str->len = max_presented_len;
return 0;
}
EXPORT_SYMBOL(fscrypt_fname_alloc_buffer);
/**
- * fscrypt_fname_crypto_free_buffer() -
+ * fscrypt_fname_free_buffer - free the buffer for presented filenames
*
- * Frees the buffer allocated for crypto operation.
+ * Free the buffer allocated by fscrypt_fname_alloc_buffer().
*/
void fscrypt_fname_free_buffer(struct fscrypt_str *crypto_str)
{
@@ -266,6 +252,10 @@ EXPORT_SYMBOL(fscrypt_fname_free_buffer)
*
* The caller must have allocated sufficient memory for the @oname string.
*
+ * If the key is available, we'll decrypt the disk name; otherwise, we'll encode
+ * it for presentation. Short names are directly base64-encoded, while long
+ * names are encoded in fscrypt_digested_name format.
+ *
* Return: 0 on success, -errno on failure
*/
int fscrypt_fname_disk_to_usr(struct inode *inode,
@@ -274,7 +264,7 @@ int fscrypt_fname_disk_to_usr(struct ino
struct fscrypt_str *oname)
{
const struct qstr qname = FSTR_TO_QSTR(iname);
- char buf[24];
+ struct fscrypt_digested_name digested_name;
if (fscrypt_is_dot_dotdot(&qname)) {
oname->name[0] = '.';
@@ -289,63 +279,62 @@ int fscrypt_fname_disk_to_usr(struct ino
if (inode->i_crypt_info)
return fname_decrypt(inode, iname, oname);
- if (iname->len <= FS_FNAME_CRYPTO_DIGEST_SIZE) {
+ if (iname->len <= FSCRYPT_FNAME_MAX_UNDIGESTED_SIZE) {
oname->len = digest_encode(iname->name, iname->len,
oname->name);
return 0;
}
if (hash) {
- memcpy(buf, &hash, 4);
- memcpy(buf + 4, &minor_hash, 4);
+ digested_name.hash = hash;
+ digested_name.minor_hash = minor_hash;
} else {
- memset(buf, 0, 8);
+ digested_name.hash = 0;
+ digested_name.minor_hash = 0;
}
- memcpy(buf + 8, iname->name + ((iname->len - 17) & ~15), 16);
+ memcpy(digested_name.digest,
+ FSCRYPT_FNAME_DIGEST(iname->name, iname->len),
+ FSCRYPT_FNAME_DIGEST_SIZE);
oname->name[0] = '_';
- oname->len = 1 + digest_encode(buf, 24, oname->name + 1);
+ oname->len = 1 + digest_encode((const char *)&digested_name,
+ sizeof(digested_name), oname->name + 1);
return 0;
}
EXPORT_SYMBOL(fscrypt_fname_disk_to_usr);
/**
- * fscrypt_fname_usr_to_disk() - converts a filename from user space to disk
- * space
+ * fscrypt_setup_filename() - prepare to search a possibly encrypted directory
+ * @dir: the directory that will be searched
+ * @iname: the user-provided filename being searched for
+ * @lookup: 1 if we're allowed to proceed without the key because it's
+ * ->lookup() or we're finding the dir_entry for deletion; 0 if we cannot
+ * proceed without the key because we're going to create the dir_entry.
+ * @fname: the filename information to be filled in
*
- * The caller must have allocated sufficient memory for the @oname string.
+ * Given a user-provided filename @iname, this function sets @fname->disk_name
+ * to the name that would be stored in the on-disk directory entry, if possible.
+ * If the directory is unencrypted this is simply @iname. Else, if we have the
+ * directory's encryption key, then @iname is the plaintext, so we encrypt it to
+ * get the disk_name.
+ *
+ * Else, for keyless @lookup operations, @iname is the presented ciphertext, so
+ * we decode it to get either the ciphertext disk_name (for short names) or the
+ * fscrypt_digested_name (for long names). Non-@lookup operations will be
+ * impossible in this case, so we fail them with ENOKEY.
+ *
+ * If successful, fscrypt_free_filename() must be called later to clean up.
*
* Return: 0 on success, -errno on failure
*/
-int fscrypt_fname_usr_to_disk(struct inode *inode,
- const struct qstr *iname,
- struct fscrypt_str *oname)
-{
- if (fscrypt_is_dot_dotdot(iname)) {
- oname->name[0] = '.';
- oname->name[iname->len - 1] = '.';
- oname->len = iname->len;
- return 0;
- }
- if (inode->i_crypt_info)
- return fname_encrypt(inode, iname, oname);
- /*
- * Without a proper key, a user is not allowed to modify the filenames
- * in a directory. Consequently, a user space name cannot be mapped to
- * a disk-space name
- */
- return -ENOKEY;
-}
-EXPORT_SYMBOL(fscrypt_fname_usr_to_disk);
-
int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname,
int lookup, struct fscrypt_name *fname)
{
- int ret = 0, bigname = 0;
+ int ret;
+ int digested;
memset(fname, 0, sizeof(struct fscrypt_name));
fname->usr_fname = iname;
- if (!dir->i_sb->s_cop->is_encrypted(dir) ||
- fscrypt_is_dot_dotdot(iname)) {
+ if (!IS_ENCRYPTED(dir) || fscrypt_is_dot_dotdot(iname)) {
fname->disk_name.name = (unsigned char *)iname->name;
fname->disk_name.len = iname->len;
return 0;
@@ -355,11 +344,17 @@ int fscrypt_setup_filename(struct inode
return ret;
if (dir->i_crypt_info) {
- ret = fscrypt_fname_alloc_buffer(dir, iname->len,
- &fname->crypto_buf);
- if (ret)
- return ret;
- ret = fname_encrypt(dir, iname, &fname->crypto_buf);
+ if (!fscrypt_fname_encrypted_size(dir, iname->len,
+ dir->i_sb->s_cop->max_namelen(dir),
+ &fname->crypto_buf.len))
+ return -ENAMETOOLONG;
+ fname->crypto_buf.name = kmalloc(fname->crypto_buf.len,
+ GFP_NOFS);
+ if (!fname->crypto_buf.name)
+ return -ENOMEM;
+
+ ret = fname_encrypt(dir, iname, fname->crypto_buf.name,
+ fname->crypto_buf.len);
if (ret)
goto errout;
fname->disk_name.name = fname->crypto_buf.name;
@@ -373,25 +368,37 @@ int fscrypt_setup_filename(struct inode
* We don't have the key and we are doing a lookup; decode the
* user-supplied name
*/
- if (iname->name[0] == '_')
- bigname = 1;
- if ((bigname && (iname->len != 33)) || (!bigname && (iname->len > 43)))
- return -ENOENT;
+ if (iname->name[0] == '_') {
+ if (iname->len !=
+ 1 + BASE64_CHARS(sizeof(struct fscrypt_digested_name)))
+ return -ENOENT;
+ digested = 1;
+ } else {
+ if (iname->len >
+ BASE64_CHARS(FSCRYPT_FNAME_MAX_UNDIGESTED_SIZE))
+ return -ENOENT;
+ digested = 0;
+ }
- fname->crypto_buf.name = kmalloc(32, GFP_KERNEL);
+ fname->crypto_buf.name =
+ kmalloc(max_t(size_t, FSCRYPT_FNAME_MAX_UNDIGESTED_SIZE,
+ sizeof(struct fscrypt_digested_name)),
+ GFP_KERNEL);
if (fname->crypto_buf.name == NULL)
return -ENOMEM;
- ret = digest_decode(iname->name + bigname, iname->len - bigname,
+ ret = digest_decode(iname->name + digested, iname->len - digested,
fname->crypto_buf.name);
if (ret < 0) {
ret = -ENOENT;
goto errout;
}
fname->crypto_buf.len = ret;
- if (bigname) {
- memcpy(&fname->hash, fname->crypto_buf.name, 4);
- memcpy(&fname->minor_hash, fname->crypto_buf.name + 4, 4);
+ if (digested) {
+ const struct fscrypt_digested_name *n =
+ (const void *)fname->crypto_buf.name;
+ fname->hash = n->hash;
+ fname->minor_hash = n->minor_hash;
} else {
fname->disk_name.name = fname->crypto_buf.name;
fname->disk_name.len = fname->crypto_buf.len;
@@ -399,16 +406,7 @@ int fscrypt_setup_filename(struct inode
return 0;
errout:
- fscrypt_fname_free_buffer(&fname->crypto_buf);
+ kfree(fname->crypto_buf.name);
return ret;
}
EXPORT_SYMBOL(fscrypt_setup_filename);
-
-void fscrypt_free_filename(struct fscrypt_name *fname)
-{
- kfree(fname->crypto_buf.name);
- fname->crypto_buf.name = NULL;
- fname->usr_fname = NULL;
- fname->disk_name.name = NULL;
-}
-EXPORT_SYMBOL(fscrypt_free_filename);
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