CVE-2021-46947

Name of the Vulnerable Software and Affected Versions Linux kernel version 5.10.20-cloudflare-2021.3.1

Description The issue arises from the efx->xdp tx queue count being initially initialized to num possible cpus() and later used to allocate and traverse efx->xdp tx queues lookup array. However, not all array slots may be initialized with real queues during probing, resulting in a NULL pointer dereference when running commands like ethtool -S <iface>. This can lead to a kernel crash.

Recommendations To resolve this issue, adjust efx->xdp tx queue count after probing to reflect the true value of initialized slots in efx->xdp tx queues. This adjustment ensures that the kernel accurately accounts for the number of queues available, preventing NULL pointer dereferences and subsequent crashes.