CVE-2024-35968

What it actually does

Deadlock in the pds_core Linux kernel driver occurs when pdsc_check_pci_health runs pci_reset_function from the health thread context, which then calls pdsc_stop_health_thread and blocks indefinitely; a secondary issue prevents safe driver unload when firmware is in fw_down state.

Why it matters to the business

Systems using affected network hardware may experience kernel thread deadlocks, driver unload failures, or forced reboots, leading to unplanned downtime and requiring manual intervention to restore service.

How an attack unfolds

An attacker with local access triggers firmware status checks that enter the fw_status == 0xff path while the health thread is active; the resulting deadlock prevents normal operation and can be reached during driver removal or hardware fault conditions.

How to fix it

Update the Linux kernel to a version containing commit 0dd3ee31125508cd67f7e7172247f05b7fd1753a or later; ensure the pds_core driver is rebuilt and loaded from the fixed tree before rebooting affected systems.

How to confirm the fix worked

Confirm the running kernel contains commit 0dd3ee31125508cd67f7e7172247f05b7fd1753a, verify pdsc_check_pci_health no longer calls pci_reset_function directly, and test driver load/unload cycles under simulated firmware-down conditions.

Typical attack path

1. Gain local access to a system with the vulnerable pds_core driver loaded
2. Trigger firmware health monitoring that observes fw_status == 0xff
3. Cause the health thread to invoke pci_reset_function
4. Observe deadlock when stop/flush of the same thread is attempted
5. Optionally trigger module unload to reach the secondary workqueue warning path

How to detect it

Review kernel logs for warnings from __queue_work during module removal or health thread operations; inspect dmesg or journalctl for traces involving pdsc_devcmd_reset, pdsc_teardown, or pdsc_remove under firmware-down states.

What your security team should do

• Prioritize kernel upgrades on all systems exposing the pds_core driver within the next maintenance window
• Add the fixed commit hash to internal kernel build and deployment pipelines
• Monitor vendor advisories for backported patches in distribution kernels