Prevent Redis from crashing from key tracking invalidations (#11814)

There is a built in limit to client side tracking keys, which when exceeded will invalidate keys. This occurs in two places, one in the server cron and other before executing a command. If it happens in the second scenario, the invalidations will be queued for later since current client is set. This queue is never drained if a command is not executed (through call) such as a multi-exec command getting queued. This results in a later server assert crashing.

1 files changed, 3 insertions, 3 deletions

diff --git a/src/tracking.c b/src/tracking.c
index 3d207563f..775eea684 100644
--- a/src/tracking.c
+++ b/src/tracking.c
@@ -393,10 +393,10 @@ void trackingInvalidateKey(client *c, robj *keyobj, int bcast) {
             continue;
         }
 
-        /* If target is current client, we need schedule key invalidation.
+        /* If target is current client and it's executing a command, we need schedule key invalidation.
          * As the invalidation messages may be interleaved with command
-         * response and should after command response */
-        if (target == server.current_client){
+         * response and should after command response. */
+        if (target == server.current_client && (server.current_client->flags & CLIENT_EXECUTING_COMMAND)) {
             incrRefCount(keyobj);
             listAddNodeTail(server.tracking_pending_keys, keyobj);
         } else {