CVE-2023-53453

What it actually does

The flaw is a kernel memory leak: atom_index_iio allocations performed during atom_parse in radeon_atombios_init are never freed in radeon_atombios_fini, leaving unreferenced 512-byte objects after driver unload.

Why it matters to the business

Systems that repeatedly load and unload the radeon driver experience gradual kernel-memory exhaustion, which can lead to performance degradation or require reboots in long-running servers or workstations using older AMD Radeon hardware.

How an attack unfolds

An attacker with local access repeatedly loads and unloads the radeon kernel module (or triggers driver probe/remove cycles) to accumulate unreferenced IIO allocations until memory pressure affects system stability; no remote or unauthenticated path exists and no named threat actors have been observed exploiting this issue.

How to fix it

Upgrade the Linux kernel to a version containing commit cb109cedbba11c33473e6780c256d8442a9e4460. For affected Debian tomcat9 packages apply version 9.0.37-1 or newer. Reboot or reload the driver after the update to release any previously leaked objects.

How to confirm the fix worked

After patching, unload and reload the radeon driver while running kmemleak or slabinfo; confirm no new unreferenced objects appear with the backtrace containing atom_parse and radeon_atombios_init. Verify the running kernel contains the cited commit hash.

Typical attack path

1. Obtain local access on a system with the radeon driver loaded
2. Trigger repeated module unload/load or PCI remove/rescan cycles
3. Monitor slab or kmemleak reports for growing unreferenced atom_parse allocations
4. Continue until memory pressure impacts availability

How to detect it

Inspect kmemleak reports and dmesg for unreferenced objects allocated in atom_parse called from radeon_atombios_init; correlate with radeon_pci_probe or driver unload timestamps in system logs.

What your security team should do

• Apply the kernel fix containing cb109cedbba11c33473e6780c256d8442a9e4460 on all systems using the radeon driver
• Prioritize patching on multi-tenant or long-uptime hosts where driver reloads occur
• Add kernel module load/unload events to monitoring for anomalous frequency
• Review and deprecate legacy radeon hardware where feasible