Re: [PATCH v36 3/7] firmware: imx: add driver for NXP EdgeLock Enclave

[Frank Li <Frank.li@oss.nxp.com>]

On Tue, Aug 18, 2026 at 08:45:26AM +0000, Pankaj Gupta (OSS) wrote:
> > > > +void se_if_rx_callback(struct mbox_client *mbox_cl, void *msg) {
> > > [ ... ]
> > > > + } else if (header->tag == priv->if_defs->rsp_tag) {
> > > [ ... ]
> > > > +         se_clbk_hdl->rx_msg_sz = min(rx_msg_sz, exp_rx_msg_sz);
> > > > +         memcpy(se_clbk_hdl->rx_msg, msg, se_clbk_hdl->rx_msg_sz);
> > >
> > > [Severity: High]
> > > If the mailbox controller driver passes a pointer to a small local
> > > buffer on the IRQ stack for msg, but the untrusted firmware-provided
> > > header->size specifies a large size, does this memcpy() read
> > > out-of-bounds past the msg pointer capacity?
> >
> > Please check this also
> >
> > Frank
> >
>
> Not an issue.
> rx_msg_sz is derived from the firmware-provided header->size field.
> It is safe to use as the source length for the memcpy() calls below
> because the MU mailbox driver (imx-mailbox.c) already validates that
> header->size does not exceed the capacity of its own fixed-size
> priv->msg buffer (sizeof(imx_sc_rpc_msg_max) = 124 bytes for
> i.MX8/i.MX93, sizeof(imx_s4_rpc_msg_max) = 1020 bytes for S4
> variants).  If firmware reports an oversized length the mailbox driver
> returns -EINVAL and never invokes this callback, so rx_msg_sz here is
> always <= the capacity of the msg pointer.  The min() / min_t() calls
> below additionally clamp the copy to the destination buffer size.
>
> >
> > > --
> > > Sashiko AI review *
> > > https://sashiko.dev/#/patchset/20260817-imx-se-if-v36-0-
> > 45c42847bfd8@o
> > > ss.nxp.com?part=3
>
> NXP Confidential

Maybe it is auto added. In public email, can't use tag "NXP Confidential"

Frank