CVE-2022-49219

Summary

In the Linux kernel, the following vulnerability has been resolved:

vfio/pci: fix memory leak during D3hot to D0 transition

If 'vfio_pci_core_device::needs_pm_restore' is set (PCI device does not have No_Soft_Reset bit set in its PMCSR config register), then the current PCI state will be saved locally in 'vfio_pci_core_device::pm_save' during D0->D3hot transition and same will be restored back during D3hot->D0 transition. For saving the PCI state locally, pci_store_saved_state() is being used and the pci_load_and_free_saved_state() will free the allocated memory.

But for reset related IOCTLs, vfio driver calls PCI reset-related API's which will internally change the PCI power state back to D0. So, when the guest resumes, then it will get the current state as D0 and it will skip the call to vfio_pci_set_power_state() for changing the power state to D0 explicitly. In this case, the memory pointed by 'pm_save' will never be freed. In a malicious sequence, the state changing to D3hot followed by VFIO_DEVICE_RESET/VFIO_DEVICE_PCI_HOT_RESET can be run in a loop and it can cause an OOM situation.

This patch frees the earlier allocated memory first before overwriting 'pm_save' to prevent the mentioned memory leak.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux51ef3a004b1eb6241e56b3aa8495769a092a4dc2 < da426ad86027b849b877d4628b277ffbbd2f5325affected
LinuxLinux51ef3a004b1eb6241e56b3aa8495769a092a4dc2 < 4319f17fb8264ba39352b611dfa913a4d8c1d1a0affected
LinuxLinux51ef3a004b1eb6241e56b3aa8495769a092a4dc2 < 26ddd196e9eb264da8e1bdc4df8a94d62581c8b5affected
LinuxLinux51ef3a004b1eb6241e56b3aa8495769a092a4dc2 < c8a1f8bd586ee31020614b8d48b702ece3e2ae44affected
LinuxLinux51ef3a004b1eb6241e56b3aa8495769a092a4dc2 < eadf88ecf6ac7d6a9f47a76c6055d9a1987a8991affected
LinuxLinux5.1affected
LinuxLinux0 < 5.1unaffected
LinuxLinux5.10.237 <= 5.10.*unaffected
LinuxLinux5.15.33 <= 5.15.*unaffected
LinuxLinux5.16.19 <= 5.16.*unaffected
LinuxLinux5.17.2 <= 5.17.*unaffected
LinuxLinux5.18 <= *unaffected

Weaknesses

ADP Enrichment

CVE Program Container

Additional References

References