diff options
Diffstat (limited to 'fs/crypto')
| -rw-r--r-- | fs/crypto/fname.c | 31 | ||||
| -rw-r--r-- | fs/crypto/fscrypt_private.h | 3 | ||||
| -rw-r--r-- | fs/crypto/hooks.c | 10 |
3 files changed, 23 insertions, 21 deletions
diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c index 44ddd094b7c5..e33f3d3c5ade 100644 --- a/fs/crypto/fname.c +++ b/fs/crypto/fname.c @@ -191,17 +191,20 @@ static int digest_decode(const char *src, int len, char *dst) return cp - dst; } -u32 fscrypt_fname_encrypted_size(const 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; - - 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); + int padding = 4 << (inode->i_crypt_info->ci_flags & + FS_POLICY_FLAGS_PAD_MASK); + u32 encrypted_len; + + 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_alloc_buffer - allocate a buffer for presented filenames @@ -342,14 +345,10 @@ int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname, return ret; if (dir->i_crypt_info) { - unsigned int max_len = dir->i_sb->s_cop->max_namelen(dir); - - if (iname->len > max_len) + 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.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) diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h index 053917587200..ad6722bae8b7 100644 --- a/fs/crypto/fscrypt_private.h +++ b/fs/crypto/fscrypt_private.h @@ -110,6 +110,9 @@ extern struct page *fscrypt_alloc_bounce_page(struct fscrypt_ctx *ctx, /* fname.c */ extern int fname_encrypt(struct inode *inode, const struct qstr *iname, u8 *out, unsigned int olen); +extern bool fscrypt_fname_encrypted_size(const struct inode *inode, + u32 orig_len, u32 max_len, + u32 *encrypted_len_ret); /* keyinfo.c */ extern void __exit fscrypt_essiv_cleanup(void); diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c index 5bf38d94c5d2..28f9f059571d 100644 --- a/fs/crypto/hooks.c +++ b/fs/crypto/hooks.c @@ -143,12 +143,12 @@ int __fscrypt_prepare_symlink(struct inode *dir, unsigned int len, * counting it (even though it is meaningless for ciphertext) is simpler * for now since filesystems will assume it is there and subtract it. */ - if (sizeof(struct fscrypt_symlink_data) + len > max_len) + if (!fscrypt_fname_encrypted_size(dir, len, + max_len - sizeof(struct fscrypt_symlink_data), + &disk_link->len)) return -ENAMETOOLONG; - disk_link->len = min_t(unsigned int, - sizeof(struct fscrypt_symlink_data) + - fscrypt_fname_encrypted_size(dir, len), - max_len); + disk_link->len += sizeof(struct fscrypt_symlink_data); + disk_link->name = NULL; return 0; } |