CVE-2024-49974 addresses a vulnerability in the Linux kernel's NFSD component where there was no limit on the number of concurrent asynchronous COPY operations clients could initiate. Each async COPY could transfer an unlimited number of 4MB chunks, potentially allowing long-running operations that could be exploited as a denial-of-service (DoS) vector. The fix introduces a per-namespace limit on concurrent background COPY operations, returning NFS4ERR_DELAY to clients exceeding this limit, allowing them to retry later or use traditional copy methods.