From: Marcel Apfelbaum <marcel@redhat.com>
Ensure mremap boundaries not trusting the guest kernel to
pass the correct buffer length.
Fixes: CVE-2021-3582
Reported-by: VictorV (Kunlun Lab) <vv474172261@gmail.com>
Tested-by: VictorV (Kunlun Lab) <vv474172261@gmail.com>
Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
---
hw/rdma/vmw/pvrdma_cmd.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/hw/rdma/vmw/pvrdma_cmd.c b/hw/rdma/vmw/pvrdma_cmd.c
index f59879e257..dadab4966b 100644
--- a/hw/rdma/vmw/pvrdma_cmd.c
+++ b/hw/rdma/vmw/pvrdma_cmd.c
@@ -38,6 +38,12 @@ static void *pvrdma_map_to_pdir(PCIDevice *pdev, uint64_t pdir_dma,
return NULL;
}
+ length = ROUND_UP(length, TARGET_PAGE_SIZE);
+ if (nchunks * TARGET_PAGE_SIZE != length) {
+ rdma_error_report("Invalid nchunks/length (%u, %lu)", nchunks, length);
+ return NULL;
+ }
+
dir = rdma_pci_dma_map(pdev, pdir_dma, TARGET_PAGE_SIZE);
if (!dir) {
rdma_error_report("Failed to map to page directory");
--
2.17.2