@@ -217,7 +217,7 @@ static int fscrypt_setup_v2_file_key(struct fscrypt_info *ci,
if (err)
return err;
- if (S_ISDIR(ci->ci_inode->i_mode)) {
+ if (S_ISDIR(ci->ci_inode->i_mode) && IS_CASEFOLDED(ci->ci_inode)) {
err = fscrypt_hkdf_expand(&mk->mk_secret.hkdf,
HKDF_CONTEXT_FNAME_HASH_KEY,
ci->ci_nonce,
@@ -10,6 +10,7 @@
* Modified by Eric Biggers, 2019 for v2 policy support.
*/
+#include <linux/key-type.h>
#include <linux/random.h>
#include <linux/string.h>
#include <linux/mount.h>
@@ -591,6 +592,8 @@ int fscrypt_ioc_setflags_prepare(struct inode *inode,
unsigned int flags)
{
union fscrypt_policy policy;
+ struct fscrypt_info *ci;
+ struct fscrypt_master_key *mk;
int err;
/*
@@ -603,6 +606,28 @@ int fscrypt_ioc_setflags_prepare(struct inode *inode,
return err;
if (policy.version != FSCRYPT_POLICY_V2)
return -EINVAL;
+ err = fscrypt_require_key(inode);
+ if (err)
+ return err;
+ ci = inode->i_crypt_info;
+ if (ci->ci_hash_key_initialized)
+ return 0;
+ mk = ci->ci_master_key->payload.data[0];
+ down_read(&mk->mk_secret_sem);
+ if (!is_master_key_secret_present(&mk->mk_secret)) {
+ err = -ENOKEY;
+ } else {
+ err = fscrypt_hkdf_expand(&mk->mk_secret.hkdf,
+ HKDF_CONTEXT_FNAME_HASH_KEY,
+ ci->ci_nonce,
+ FS_KEY_DERIVATION_NONCE_SIZE,
+ (u8 *)&ci->ci_hash_key,
+ sizeof(ci->ci_hash_key));
+ }
+ up_read(&mk->mk_secret_sem);
+ if (err)
+ return err;
+ ci->ci_hash_key_initialized = true;
}
return 0;
If a directory isn't casefolded, it doesn't need the hash key. Skip deriving it unless we enable it later. Signed-off-by: Daniel Rosenberg <drosen@google.com> --- fs/crypto/keysetup.c | 2 +- fs/crypto/policy.c | 25 +++++++++++++++++++++++++ 2 files changed, 26 insertions(+), 1 deletion(-)