VMCI: Fix possible memcpy() run-time warning in vmci_datagram_invoke_guest_handler()

The changes are similar to those given in the commit 19b070fefd0d
("VMCI: Fix memcpy() run-time warning in dg_dispatch_as_host()").

Fix filling of the msg and msg_payload in dg_info struct, which prevents a
possible "detected field-spanning write" of memcpy warning that is issued
by the tracking mechanism __fortify_memcpy_chk.

Signed-off-by: Vasiliy Kovalev <kovalev@altlinux.org>
Link: https://lore.kernel.org/r/20240219105315.76955-1-kovalev@altlinux.org
Signed-off-by: Kees Cook <keescook@chromium.org>

diff --git a/drivers/misc/vmw_vmci/vmci_datagram.c b/drivers/misc/vmw_vmci/vmci_datagram.c
index ba379cd6d054bdeb53c6d050a9b03443ab34b17e..3964d9e5a39b5d41ce51fcc32945362968ec376b 100644 (file)
--- a/drivers/misc/vmw_vmci/vmci_datagram.c
+++ b/drivers/misc/vmw_vmci/vmci_datagram.c
@@ -378,7 +378,8 @@ int vmci_datagram_invoke_guest_handler(struct vmci_datagram *dg)
 
                dg_info->in_dg_host_queue = false;
                dg_info->entry = dst_entry;
-               memcpy(&dg_info->msg, dg, VMCI_DG_SIZE(dg));
+               dg_info->msg = *dg;
+               memcpy(&dg_info->msg_payload, dg + 1, dg->payload_size);
 
                INIT_WORK(&dg_info->work, dg_delayed_dispatch);
                schedule_work(&dg_info->work);