diff options
Diffstat (limited to 'fs/crypto')
| -rw-r--r-- | fs/crypto/fname.c | 53 | ||||
| -rw-r--r-- | fs/crypto/fscrypt_private.h | 4 | ||||
| -rw-r--r-- | fs/crypto/hooks.c | 7 |
3 files changed, 29 insertions, 35 deletions
diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c index cae7d1bcc8c5..65424b89a1d1 100644 --- a/fs/crypto/fname.c +++ b/fs/crypto/fname.c @@ -30,39 +30,29 @@ static inline bool fscrypt_is_dot_dotdot(const struct qstr *str) /** * 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 */ -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_CRYPTO_WAIT(wait); - struct fscrypt_info *ci = inode->i_crypt_info; - struct crypto_skcipher *tfm = ci->ci_ctfm; + 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. */ - if (WARN_ON(oname->len < iname->len)) + if (WARN_ON(olen < iname->len)) return -ENOBUFS; - cryptlen = max_t(unsigned int, iname->len, FS_CRYPTO_BLOCK_SIZE); - cryptlen = round_up(cryptlen, padding); - cryptlen = min3(cryptlen, lim, oname->len); - memcpy(oname->name, iname->name, iname->len); - memset(oname->name + iname->len, 0, cryptlen - iname->len); + memcpy(out, iname->name, iname->len); + memset(out + iname->len, 0, olen - iname->len); /* Initialize the IV */ memset(iv, 0, FS_CRYPTO_BLOCK_SIZE); @@ -77,8 +67,8 @@ int fname_encrypt(struct inode *inode, skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, crypto_req_done, &wait); - sg_init_one(&sg, oname->name, cryptlen); - skcipher_request_set_crypt(req, &sg, &sg, cryptlen, iv); + sg_init_one(&sg, out, olen); + skcipher_request_set_crypt(req, &sg, &sg, olen, iv); /* Do the encryption */ res = crypto_wait_req(crypto_skcipher_encrypt(req), &wait); @@ -89,7 +79,6 @@ int fname_encrypt(struct inode *inode, return res; } - oname->len = cryptlen; return 0; } @@ -354,11 +343,21 @@ int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname, 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); + unsigned int max_len = dir->i_sb->s_cop->max_namelen(dir); + + if (iname->len > max_len) + return -ENAMETOOLONG; + + fname->crypto_buf.len = + min(fscrypt_fname_encrypted_size(dir, iname->len), + max_len); + 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; @@ -410,7 +409,7 @@ int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname, return 0; errout: - fscrypt_fname_free_buffer(&fname->crypto_buf); + kfree(fname->crypto_buf.name); return ret; } EXPORT_SYMBOL(fscrypt_setup_filename); diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h index cec9ce309f41..053917587200 100644 --- a/fs/crypto/fscrypt_private.h +++ b/fs/crypto/fscrypt_private.h @@ -108,8 +108,8 @@ extern struct page *fscrypt_alloc_bounce_page(struct fscrypt_ctx *ctx, gfp_t gfp_flags); /* fname.c */ -extern int fname_encrypt(struct inode *inode, - const struct qstr *iname, struct fscrypt_str *oname); +extern int fname_encrypt(struct inode *inode, const struct qstr *iname, + u8 *out, unsigned int olen); /* keyinfo.c */ extern void __exit fscrypt_essiv_cleanup(void); diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c index 8900e348ba6e..5bf38d94c5d2 100644 --- a/fs/crypto/hooks.c +++ b/fs/crypto/hooks.c @@ -161,7 +161,6 @@ int __fscrypt_encrypt_symlink(struct inode *inode, const char *target, struct qstr iname = { .name = target, .len = len }; struct fscrypt_symlink_data *sd; unsigned int ciphertext_len; - struct fscrypt_str oname; err = fscrypt_require_key(inode); if (err) @@ -178,16 +177,12 @@ int __fscrypt_encrypt_symlink(struct inode *inode, const char *target, ciphertext_len = disk_link->len - sizeof(*sd); sd->len = cpu_to_le16(ciphertext_len); - oname.name = sd->encrypted_path; - oname.len = ciphertext_len; - err = fname_encrypt(inode, &iname, &oname); + err = fname_encrypt(inode, &iname, sd->encrypted_path, ciphertext_len); if (err) { if (!disk_link->name) kfree(sd); return err; } - BUG_ON(oname.len != ciphertext_len); - /* * Null-terminating the ciphertext doesn't make sense, but we still * count the null terminator in the length, so we might as well |