Fabian Grünbichler

**Name of the Vulnerable Software and Affected Versions** Linux kernel versions 4.11.x through 4.11-rc7 **Description** The cookie feature in the packet action API implementation mishandles the tb nlattr array, allowing local users to cause a denial of service, such as uninitialized memory access and refcount underflow, which can lead to system hang or crash. This issue can be exploited via "tc filter add" commands in certain contexts. **Recommendations** For Linux kernel versions 4.11.x through 4.11-rc7, consider restricting access to the "tc filter add" command to minimize the risk of exploitation until a patch is available. As a temporary workaround, avoid using the "tc filter add" command in sensitive contexts until the issue is resolved. At the moment, there is no information about a newer version that contains a fix for this vulnerability.