2024-02-19 10:56:21

by Vasiliy Kovalev

Subject: [PATCH] VMCI: Fix possible memcpy() run-time warning in vmci_datagram_invoke_guest_handler()

From: Vasiliy Kovalev <[email protected]>

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 <[email protected]>
---
drivers/misc/vmw_vmci/vmci_datagram.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/vmw_vmci/vmci_datagram.c b/drivers/misc/vmw_vmci/vmci_datagram.c
index d1d8224c8800c4..a0ad1f3a69f7e9 100644
--- 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);
--
2.33.8

2024-03-01 06:42:48

by Kees Cook

Subject: Re: [PATCH] VMCI: Fix possible memcpy() run-time warning in vmci_datagram_invoke_guest_handler()

On Mon, 19 Feb 2024 13:53:15 +0300, [email protected] wrote:
> 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.
>
> [...]

Since I ended up carrying the other fix, I can carry this one too. :)

Applied to for-next/hardening, thanks!

[1/1] VMCI: Fix possible memcpy() run-time warning in vmci_datagram_invoke_guest_handler()
https://git.kernel.org/kees/c/1ce15647a1aa

Take care,

--
Kees Cook