Linux Kernel RDMA hfi1 Divide-By-Zero Vulnerability in find_hw_thread_mask Function

A vulnerability in the Linux kernel's RDMA subsystem, specifically within the hfi1 driver, can lead to a divide-by-zero runtime error. This issue arises in the find_hw_thread_mask function, which improperly checks the number of core siblings before performing a division. The vulnerability is present in the Linux kernel stable tree.

Impact

Exploitation of this vulnerability can cause a divide-by-zero runtime error, potentially leading to a denial-of-service condition.

Reproduction

The vulnerability can be reproduced by invoking the find_hw_thread_mask function in the hfi1 driver when the num_core_siblings parameter is set to zero. This can be done by configuring the system to have no core siblings or by manipulating the affinity settings of the hfi1 driver.

Remediation

Users can upgrade to the latest version of the Linux kernel where this vulnerability has been patched. Instructions for upgrading the Linux kernel can be found in the official Linux kernel documentation.