In the Linux kernel, the following vulnerability has been resolved: PCI: endpoint: pci-ep-msi: Fix error unwind and prevent double alloc pci_epf_alloc_doorbell() stores the allocated doorbell message array in epf->db_msg/epf->num_db before requesting MSI vectors. If MSI allocation fails, the array is freed but the EPF state may still point to freed memory. Clear epf->db_msg and epf->num_db on the MSI allocation failure path so that later cleanup cannot double-free the array and callers can retry allocation. Also return -EBUSY when doorbells have already been allocated to prevent leaking or overwriting an existing allocation.
https://git.kernel.org/stable/c/3c25587fbf8797b92090b064a6d239a873e55fb1
https://git.kernel.org/stable/c/1cba96c0a795124c3229293ed7b5b5765e66f259
https://git.kernel.org/stable/c/175717cfc06cab79f84cd037d66dda1b8564cd9e