From: Koichiro Den Date: Tue, 17 Feb 2026 06:38:56 +0000 (+0900) Subject: PCI: endpoint: pci-ep-msi: Fix error unwind and prevent double alloc X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1cba96c0a795124c3229293ed7b5b5765e66f259;p=thirdparty%2Fkernel%2Flinux.git 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. Fixes: 1c3b002c6bf6 ("PCI: endpoint: Add RC-to-EP doorbell support using platform MSI controller") Signed-off-by: Koichiro Den Signed-off-by: Manivannan Sadhasivam Reviewed-by: Frank Li Reviewed-by: Niklas Cassel Link: https://patch.msgid.link/20260217063856.3759713-4-den@valinux.co.jp --- diff --git a/drivers/pci/endpoint/pci-ep-msi.c b/drivers/pci/endpoint/pci-ep-msi.c index 51c19942a81ef..1395919571f83 100644 --- a/drivers/pci/endpoint/pci-ep-msi.c +++ b/drivers/pci/endpoint/pci-ep-msi.c @@ -50,6 +50,9 @@ int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 num_db) return -EINVAL; } + if (epf->db_msg) + return -EBUSY; + domain = of_msi_map_get_device_domain(epc->dev.parent, 0, DOMAIN_BUS_PLATFORM_MSI); if (!domain) { @@ -79,6 +82,8 @@ int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 num_db) if (ret) { dev_err(dev, "Failed to allocate MSI\n"); kfree(msg); + epf->db_msg = NULL; + epf->num_db = 0; return ret; }