Re: [PATCH 4/4] PCI: endpoint: pci-ep-msi: Fix error unwind and prevent double alloc

Niklas Cassel
2026-02-16T11:57:46Z

On Mon, Feb 16, 2026 at 12:09:14AM +0900, Koichiro Den wrote:
> 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.
>
> Fixes: 1c3b002c6bf6 ("PCI: endpoint: Add RC-to-EP doorbell support using platform MSI controller")
> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Signed-off-by: Koichiro Den <den@valinux.co.jp>
> ---

Reviewed-by: Niklas Cassel <cassel@kernel.org>