Re: [PATCH] net: vmw_vsock: vmci: Check memcpy_from_msg()

[Vishnu Dasa <vdasa@vmware.com>]

> On Dec 2, 2022, at 2:58 PM, Artem Chernyshev <artem.chernyshev@red-soft.ru> wrote:
> 
> We returns from vmci_transport_dgram_enqueue() with error
> if memcpy goes wrong

Thanks for the patch.

Nit: could you please update the description?  Maybe something like -
vmci_transport_dgram_enqueue() does not check the return value
of memcpy_from_msg(). Return with an error if the memcpy fails.

> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Fixes: 0f7db23a07af ("vmci_transport: switch ->enqeue_dgram, ->enqueue_stream and ->dequeue_stream to msghdr")
> Signed-off-by: Artem Chernyshev <artem.chernyshev@red-soft.ru>
> ---
> net/vmw_vsock/vmci_transport.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
> index 842c94286d31..7994090e0314 100644
> --- a/net/vmw_vsock/vmci_transport.c
> +++ b/net/vmw_vsock/vmci_transport.c
> @@ -1711,7 +1711,8 @@ static int vmci_transport_dgram_enqueue(
> 	if (!dg)
> 		return -ENOMEM;
> 
> -	memcpy_from_msg(VMCI_DG_PAYLOAD(dg), msg, len);
> +	if (memcpy_from_msg(VMCI_DG_PAYLOAD(dg), msg, len))

Need to free dg using kfree() before returning.

> +		return -EFAULT;
> 
> 	dg->dst = vmci_make_handle(remote_addr->svm_cid,
> 				   remote_addr->svm_port);
> -- 
> 2.30.3
>