hw/rdma: Fix possible mremap overflow in the pvrdma device (CVE-2021-3582)

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>
Message-Id: <20210616110600.20889-1-marcel.apfelbaum@gmail.com>
Reviewed-by: Yuval Shaia <yuval.shaia.ml@gmail.com>
Tested-by: Yuval Shaia <yuval.shaia.ml@gmail.com>
Reviewed-by: Prasad J Pandit <pjp@fedoraproject.org>
Signed-off-by: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
This commit is contained in:
Marcel Apfelbaum 2021-06-16 14:06:00 +03:00 committed by Marcel Apfelbaum
parent 9c2647f750
commit 284f191b4a

View File

@ -38,6 +38,13 @@ 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,
(unsigned long)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");