CVE-2023-53549

An uncontrolled resource consumption flaw was found in the Linux kernel's netfilter ipset subsystem when processing large batch operations. A local user with CAP_NET_ADMIN capability can trigger this issue by adding or deleting a large number of ipset entries in a single operation, causing the kernel to execute long-running tasks without yielding. This results in soft lockup conditions and denial of service through system unresponsiveness.

The ipset code processes batch add/delete operations in a tight loop while holding the nfnl mutex. When users specify a large range of IP addresses or ports to add to or remove from a set, the kernel can spend extended periods (potentially seconds) without scheduling, leading to soft lockup detector warnings and system unresponsiveness. Previous attempts to limit the batch size were insufficient—the limits were still too high to prevent hung task conditions on slower systems. Exploitation requires CAP_NET_ADMIN capability, which is typically restricted to root or containers with explicit network administration privileges.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.