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>
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");