KEYS: Load key expiry time atomically in keyring_search_iterator()

Similar to the case for key_validate(), we should load the key ->expiry once atomically in keyring_search_iterator(), since it can be changed concurrently with the flags whenever the key semaphore isn't held. Signed-off-by: Eric Biggers <[email protected]> Signed-off-by: David Howells <[email protected]>
ambv · Oct 18, 2017 · 9d6c871 · 9d6c871
1 parent 1823d47
commit 9d6c871
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
@@ -566,14 +566,16 @@ static int keyring_search_iterator(const void *object, void *iterator_data)
 
 	/* skip invalidated, revoked and expired keys */
 	if (ctx->flags & KEYRING_SEARCH_DO_STATE_CHECK) {
+		time_t expiry = READ_ONCE(key->expiry);
+
 		if (kflags & ((1 << KEY_FLAG_INVALIDATED) |
 			      (1 << KEY_FLAG_REVOKED))) {
 			ctx->result = ERR_PTR(-EKEYREVOKED);
 			kleave(" = %d [invrev]", ctx->skipped_ret);
 			goto skipped;
 		}
 
-		if (key->expiry && ctx->now.tv_sec >= key->expiry) {
+		if (expiry && ctx->now.tv_sec >= expiry) {
 			if (!(ctx->flags & KEYRING_SEARCH_SKIP_EXPIRED))
 				ctx->result = ERR_PTR(-EKEYEXPIRED);
 			kleave(" = %d [expire]", ctx->skipped_ret);