Ubuntu Linux Bluefield DDoS-Induced Kernel Crash Vulnerability

A vulnerability in the Ubuntu Linux Bluefield package, specifically in version 5.4.0-1001.2 prior to 5.4.0-1058.64 on the Focal release, causes a kernel crash when a DDoS attack is executed on TCP port 22. This issue arises from a backported commit related to 'nft_lookup' that was applied without subsequent necessary fixes. The vulnerability can be exploited by flooding the 'SmartNIC' IP address with packets directed to port 22, using a tool like 'hping3'.

Impact

Exploitation of this vulnerability leads to a kernel crash, causing a denial of service on the affected system.

Reproduction

The vulnerability can be reproduced by configuring nftables to direct new TCP connections on port 22 to a custom chain that accepts them. After applying this configuration, 'hping3' can be used to flood the 'SmartNIC' IP address on port 22, which will trigger the kernel crash.

Remediation

Users can upgrade to the linux-bluefield package version 5.4.0-1058.64 to address this vulnerability.