[PATCH v2 6/6] KEYS: remove KEY_FLAG_NEGATIVE

Eric Biggers
2017-09-26T20:15:57Z

Now that a key's reject_error is stored in the flags word, we can check
for nonzero reject_error rather than for KEY_FLAG_NEGATIVE. Do this,
then remove KEY_FLAG_NEGATIVE.

Signed-off-by: Eric Biggers <ebiggers@google.com>
---
include/linux/key.h | 20 ++++++++++++--------
security/keys/encrypted-keys/encrypted.c | 2 +-
security/keys/gc.c | 4 +---
security/keys/key.c | 4 +---
security/keys/keyctl.c | 2 +-
security/keys/keyring.c | 2 +-
security/keys/proc.c | 2 +-
security/keys/request_key.c | 2 +-
security/keys/trusted.c | 2 +-
security/keys/user_defined.c | 2 +-
10 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/include/linux/key.h b/include/linux/key.h
index fcb79eedbdb5..ecae4c1e4375 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -181,13 +181,12 @@ struct key {
#define KEY_FLAG_REVOKED 2 /* set if key had been revoked */
#define KEY_FLAG_IN_QUOTA 3 /* set if key consumes quota */
#define KEY_FLAG_USER_CONSTRUCT 4 /* set if key is being constructed in userspace */
-#define KEY_FLAG_NEGATIVE 5 /* set if key is negative */
-#define KEY_FLAG_ROOT_CAN_CLEAR 6 /* set if key can be cleared by root without permission */
-#define KEY_FLAG_INVALIDATED 7 /* set if key has been invalidated */
-#define KEY_FLAG_BUILTIN 8 /* set if key is built in to the kernel */
-#define KEY_FLAG_ROOT_CAN_INVAL 9 /* set if key can be invalidated by root without permission */
-#define KEY_FLAG_KEEP 10 /* set if key should not be removed */
-#define KEY_FLAG_UID_KEYRING 11 /* set if key is a user or user session keyring */
+#define KEY_FLAG_ROOT_CAN_CLEAR 5 /* set if key can be cleared by root without permission */
+#define KEY_FLAG_INVALIDATED 6 /* set if key has been invalidated */
+#define KEY_FLAG_BUILTIN 7 /* set if key is built in to the kernel */
+#define KEY_FLAG_ROOT_CAN_INVAL 8 /* set if key can be invalidated by root without permission */
+#define KEY_FLAG_KEEP 9 /* set if key should not be removed */
+#define KEY_FLAG_UID_KEYRING 10 /* set if key is a user or user session keyring */

/*
* If the key is negatively instantiated, then bits 20-31 hold the error
@@ -376,7 +375,12 @@ static inline bool key_is_instantiated(const struct key *key)
unsigned long flags = smp_load_acquire(&key->flags);

return (flags & KEY_FLAG_INSTANTIATED) &&
- !(flags & KEY_FLAG_NEGATIVE);
+ !(flags & KEY_FLAGS_REJECT_ERROR_MASK);
+}
+
+static inline bool key_is_negative(const struct key *key)
+{
+ return key->flags & KEY_FLAGS_REJECT_ERROR_MASK;
}

#define dereference_key_rcu(KEY) \
diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c
index 69855ba0d3b3..f54b92868bc3 100644
--- a/security/keys/encrypted-keys/encrypted.c
+++ b/security/keys/encrypted-keys/encrypted.c
@@ -847,7 +847,7 @@ static int encrypted_update(struct key *key, struct key_preparsed_payload *prep)
size_t datalen = prep->datalen;
int ret = 0;

- if (test_bit(KEY_FLAG_NEGATIVE, &key->flags))
+ if (key_is_negative(key))
return -ENOKEY;
if (datalen <= 0 || datalen > 32767 || !prep->data)
return -EINVAL;
diff --git a/security/keys/gc.c b/security/keys/gc.c
index 87cb260e4890..0adc52be3ea9 100644
--- a/security/keys/gc.c
+++ b/security/keys/gc.c
@@ -135,9 +135,7 @@ static noinline void key_gc_unused_keys(struct list_head *keys)
key_check(key);

/* Throw away the key data if the key is instantiated */
- if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags) &&
- !test_bit(KEY_FLAG_NEGATIVE, &key->flags) &&
- key->type->destroy)
+ if (key_is_instantiated(key) && key->type->destroy)
key->type->destroy(key);

security_key_free(key);
diff --git a/security/keys/key.c b/security/keys/key.c
index 3ffb6829972f..990573a14666 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -407,10 +407,8 @@ static void mark_key_instantiated(struct key *key, unsigned int reject_error)

do {
old = READ_ONCE(key->flags);
- new = (old & ~(KEY_FLAG_NEGATIVE |
- KEY_FLAGS_REJECT_ERROR_MASK)) |
+ new = (old & ~KEY_FLAGS_REJECT_ERROR_MASK) |
KEY_FLAG_INSTANTIATED |
- (reject_error ? KEY_FLAG_NEGATIVE : 0) |
(reject_error << KEY_FLAGS_REJECT_ERROR_SHIFT);
} while (cmpxchg_release(&key->flags, old, new) != old);
}
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 19a09e121089..e90b352cc3bd 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -766,7 +766,7 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen)

key = key_ref_to_ptr(key_ref);

- if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) {
+ if (key_is_negative(key)) {
ret = -ENOKEY;
goto error2;
}
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 1dfff0eac474..16d21d0e5e45 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -599,7 +599,7 @@ static int keyring_search_iterator(const void *object, void *iterator_data)

if (ctx->flags & KEYRING_SEARCH_DO_STATE_CHECK) {
/* we set a different error code if we pass a negative key */
- if (kflags & (1 << KEY_FLAG_NEGATIVE)) {
+ if (kflags & KEY_FLAGS_REJECT_ERROR_MASK) {
ctx->result = ERR_PTR(-(int)(kflags >>
KEY_FLAGS_REJECT_ERROR_SHIFT));
kleave(" = %d [neg]", ctx->skipped_ret);
diff --git a/security/keys/proc.c b/security/keys/proc.c
index a038069ac46a..7d34e70f8aa1 100644
--- a/security/keys/proc.c
+++ b/security/keys/proc.c
@@ -250,7 +250,7 @@ static int proc_keys_show(struct seq_file *m, void *v)
showflag(flags, 'D', KEY_FLAG_DEAD),
showflag(flags, 'Q', KEY_FLAG_IN_QUOTA),
showflag(flags, 'U', KEY_FLAG_USER_CONSTRUCT),
- showflag(flags, 'N', KEY_FLAG_NEGATIVE),
+ (flags & KEY_FLAGS_REJECT_ERROR_MASK) ? 'N' : '-',
showflag(flags, 'i', KEY_FLAG_INVALIDATED),
refcount_read(&key->usage),
xbuf,
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 0aab68344837..1953ceb33efc 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -599,7 +599,7 @@ int wait_for_key_construction(struct key *key, bool intr)

/* Pairs with RELEASE in mark_key_instantiated() */
flags = smp_load_acquire(&key->flags);
- if (flags & (1 << KEY_FLAG_NEGATIVE))
+ if (flags & KEY_FLAGS_REJECT_ERROR_MASK)
return -(int)(flags >> KEY_FLAGS_REJECT_ERROR_SHIFT);

return key_validate(key);
diff --git a/security/keys/trusted.c b/security/keys/trusted.c
index ddfaebf60fc8..bd85315cbfeb 100644
--- a/security/keys/trusted.c
+++ b/security/keys/trusted.c
@@ -1066,7 +1066,7 @@ static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
char *datablob;
int ret = 0;

- if (test_bit(KEY_FLAG_NEGATIVE, &key->flags))
+ if (key_is_negative(key))
return -ENOKEY;
p = key->payload.data[0];
if (!p->migratable)
diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c
index 3d8c68eba516..a5506400836c 100644
--- a/security/keys/user_defined.c
+++ b/security/keys/user_defined.c
@@ -114,7 +114,7 @@ int user_update(struct key *key, struct key_preparsed_payload *prep)

/* attach the new data, displacing the old */
key->expiry = prep->expiry;
- if (!test_bit(KEY_FLAG_NEGATIVE, &key->flags))
+ if (!key_is_negative(key))
zap = dereference_key_locked(key);
rcu_assign_keypointer(key, prep->payload.data[0]);
prep->payload.data[0] = NULL;
--
2.14.1.992.g2c7b836f3a-goog