CVE-2023-53611

A memory leak flaw was found in the Linux kernel's IPMI System Interface driver in the initialization error path. A local user can trigger this issue by loading the ipmi_si module when initialization fails after allocating the si_sm structure but before registering the shutdown handler. This causes the allocated memory to never be freed, resulting in a permanent memory leak leading to resource exhaustion and denial of service.

The try_smi_init function performs IPMI interface initialization and allocates the new_smi->si_sm structure early in the process. If an error occurs after this allocation but before the shutdown_smi handler is registered, the error cleanup path returns without freeing si_sm because shutdown_smi is the normal mechanism for releasing this resource. Since initialization failures don't retry, each failed attempt permanently leaks 1024 bytes. While individual leaks are relatively small, repeated module load attempts (such as through automatic hardware detection or manual troubleshooting) can accumulate significant memory loss.

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.

To mitigate this issue, prevent the ipmi_si module from being loaded. See https://access.redhat.com/solutions/41278 for instructions on blacklisting kernel modules.