CVE-2023-53755

AMD PTDMA (Pass-Through DMA) engine crashes the kernel when pt_issue_pending() encounters empty descriptor queues. The function blindly invokes pt_cmd_callback() without verifying that a valid descriptor exists, triggering a NULL pointer dereference. This commonly surfaces during system shutdown on AMD platforms after the DMA engine has been active.

Systems with AMD processors utilizing PTDMA are vulnerable to kernel panics during specific shutdown sequences. The timing-dependent nature of this bug reduces reproducibility in normal operation.

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 ptdma module from being loaded. See https://access.redhat.com/solutions/41278 for instructions on how to blacklist a kernel module.