eCryptfs: write lock requested keys
A requested key is write locked in order to prevent modifications on the
authentication token while it is being used.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index d95dd50..03e609c 100644
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -516,10 +516,11 @@
goto out_invalid_auth_tok;
}
+ down_write(&(walker->global_auth_tok_key->sem));
rc = ecryptfs_verify_auth_tok_from_key(
walker->global_auth_tok_key, auth_tok);
if (rc)
- goto out_invalid_auth_tok;
+ goto out_invalid_auth_tok_unlock;
(*auth_tok_key) = walker->global_auth_tok_key;
key_get(*auth_tok_key);
@@ -527,6 +528,8 @@
}
rc = -ENOENT;
goto out;
+out_invalid_auth_tok_unlock:
+ up_write(&(walker->global_auth_tok_key->sem));
out_invalid_auth_tok:
printk(KERN_WARNING "Invalidating auth tok with sig = [%s]\n", sig);
walker->flags |= ECRYPTFS_AUTH_TOK_INVALID;
@@ -869,8 +872,10 @@
out_unlock:
mutex_unlock(s->tfm_mutex);
out:
- if (auth_tok_key)
+ if (auth_tok_key) {
+ up_write(&(auth_tok_key->sem));
key_put(auth_tok_key);
+ }
kfree(s);
return rc;
}
@@ -1106,8 +1111,10 @@
(*filename_size) = 0;
(*filename) = NULL;
}
- if (auth_tok_key)
+ if (auth_tok_key) {
+ up_write(&(auth_tok_key->sem));
key_put(auth_tok_key);
+ }
kfree(s);
return rc;
}
@@ -1638,9 +1645,10 @@
(*auth_tok_key) = NULL;
goto out;
}
-
+ down_write(&(*auth_tok_key)->sem);
rc = ecryptfs_verify_auth_tok_from_key(*auth_tok_key, auth_tok);
if (rc) {
+ up_write(&(*auth_tok_key)->sem);
key_put(*auth_tok_key);
(*auth_tok_key) = NULL;
goto out;
@@ -1865,6 +1873,7 @@
find_next_matching_auth_tok:
found_auth_tok = 0;
if (auth_tok_key) {
+ up_write(&(auth_tok_key->sem));
key_put(auth_tok_key);
auth_tok_key = NULL;
}
@@ -1951,8 +1960,10 @@
out_wipe_list:
wipe_auth_tok_list(&auth_tok_list);
out:
- if (auth_tok_key)
+ if (auth_tok_key) {
+ up_write(&(auth_tok_key->sem));
key_put(auth_tok_key);
+ }
return rc;
}
@@ -2446,6 +2457,7 @@
rc = -EINVAL;
goto out_free;
}
+ up_write(&(auth_tok_key->sem));
key_put(auth_tok_key);
auth_tok_key = NULL;
}
@@ -2460,8 +2472,10 @@
out:
if (rc)
(*len) = 0;
- if (auth_tok_key)
+ if (auth_tok_key) {
+ up_write(&(auth_tok_key->sem));
key_put(auth_tok_key);
+ }
mutex_unlock(&crypt_stat->keysig_list_mutex);
return rc;