From 9937fa6d1eb6fac95586970e17617a718919c858 Mon Sep 17 00:00:00 2001 From: "Andrea Parri (Microsoft)" Date: Thu, 12 May 2022 00:32:06 +0200 Subject: PCI: hv: Add validation for untrusted Hyper-V values For additional robustness in the face of Hyper-V errors or malicious behavior, validate all values that originate from packets that Hyper-V has sent to the guest in the host-to-guest ring buffer. Ensure that invalid values cannot cause data being copied out of the bounds of the source buffer in hv_pci_onchannelcallback(). While at it, remove a redundant validation in hv_pci_generic_compl(): hv_pci_onchannelcallback() already ensures that all processed incoming packets are "at least as large as [in fact larger than] a response". Signed-off-by: Andrea Parri (Microsoft) Reviewed-by: Michael Kelley Acked-by: Lorenzo Pieralisi Link: https://lore.kernel.org/r/20220511223207.3386-2-parri.andrea@gmail.com Signed-off-by: Wei Liu --- drivers/pci/controller/pci-hyperv.c | 33 ++++++++++++++++++++++++--------- 1 file changed, 24 insertions(+), 9 deletions(-) (limited to 'drivers/pci/controller/pci-hyperv.c') diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c index e439b810f974..a06e2cf94658 100644 --- a/drivers/pci/controller/pci-hyperv.c +++ b/drivers/pci/controller/pci-hyperv.c @@ -981,11 +981,7 @@ static void hv_pci_generic_compl(void *context, struct pci_response *resp, { struct hv_pci_compl *comp_pkt = context; - if (resp_packet_size >= offsetofend(struct pci_response, status)) - comp_pkt->completion_status = resp->status; - else - comp_pkt->completion_status = -1; - + comp_pkt->completion_status = resp->status; complete(&comp_pkt->host_event); } @@ -1606,8 +1602,13 @@ static void hv_pci_compose_compl(void *context, struct pci_response *resp, struct pci_create_int_response *int_resp = (struct pci_create_int_response *)resp; + if (resp_packet_size < sizeof(*int_resp)) { + comp_pkt->comp_pkt.completion_status = -1; + goto out; + } comp_pkt->comp_pkt.completion_status = resp->status; comp_pkt->int_desc = int_resp->int_desc; +out: complete(&comp_pkt->comp_pkt.host_event); } @@ -2291,12 +2292,14 @@ static void q_resource_requirements(void *context, struct pci_response *resp, struct q_res_req_compl *completion = context; struct pci_q_res_req_response *q_res_req = (struct pci_q_res_req_response *)resp; + s32 status; int i; - if (resp->status < 0) { + status = (resp_packet_size < sizeof(*q_res_req)) ? -1 : resp->status; + if (status < 0) { dev_err(&completion->hpdev->hbus->hdev->device, "query resource requirements failed: %x\n", - resp->status); + status); } else { for (i = 0; i < PCI_STD_NUM_BARS; i++) { completion->hpdev->probed_bar[i] = @@ -2848,7 +2851,8 @@ static void hv_pci_onchannelcallback(void *context) case PCI_BUS_RELATIONS: bus_rel = (struct pci_bus_relations *)buffer; - if (bytes_recvd < + if (bytes_recvd < sizeof(*bus_rel) || + bytes_recvd < struct_size(bus_rel, func, bus_rel->device_count)) { dev_err(&hbus->hdev->device, @@ -2862,7 +2866,8 @@ static void hv_pci_onchannelcallback(void *context) case PCI_BUS_RELATIONS2: bus_rel2 = (struct pci_bus_relations2 *)buffer; - if (bytes_recvd < + if (bytes_recvd < sizeof(*bus_rel2) || + bytes_recvd < struct_size(bus_rel2, func, bus_rel2->device_count)) { dev_err(&hbus->hdev->device, @@ -2876,6 +2881,11 @@ static void hv_pci_onchannelcallback(void *context) case PCI_EJECT: dev_message = (struct pci_dev_incoming *)buffer; + if (bytes_recvd < sizeof(*dev_message)) { + dev_err(&hbus->hdev->device, + "eject message too small\n"); + break; + } hpdev = get_pcichild_wslot(hbus, dev_message->wslot.slot); if (hpdev) { @@ -2887,6 +2897,11 @@ static void hv_pci_onchannelcallback(void *context) case PCI_INVALIDATE_BLOCK: inval = (struct pci_dev_inval_block *)buffer; + if (bytes_recvd < sizeof(*inval)) { + dev_err(&hbus->hdev->device, + "invalidate message too small\n"); + break; + } hpdev = get_pcichild_wslot(hbus, inval->wslot.slot); if (hpdev) { -- cgit v1.2.3