CVE-2023-53631

A reference leak flaw was found in the Linux kernel's Dell system management driver in the attribute duplicate detection logic. A local user on Dell systems can trigger this issue when the driver encounters duplicate sysfs attributes during initialization, causing a kobject reference to be acquired via kset_find_obj but never released. This results in a permanent reference leak that prevents proper cleanup and leads to resource exhaustion or denial of service.

The dell-sysman driver uses kset_find_obj to check for duplicate attributes in sysfs. When a duplicate is found, the function returns a reference to the existing kobject, incrementing its reference count. However, the driver fails to call kobject_put to release this reference, violating the kernel's reference counting rules. Over time or across multiple driver load/unload cycles, these leaked references accumulate, preventing proper object cleanup and potentially exhausting kernel resources. Triggering requires Dell hardware with the system management interface and conditions that create duplicate attributes, which may occur through specific BIOS configurations or repeated driver operations.

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 dell_wmi_sysman module from being loaded. See https://access.redhat.com/solutions/41278 for instructions on blacklisting kernel modules.