On Mon, Sep 26, 2022 at 05:40:11PM -0700, Kees Cook wrote: > To work around a misbehavior of the compiler's ability to see into > composite flexible array structs (as detailed in the coming memcpy() > hardening series[1]), split the memcpy() of the header and the payload > so no false positive run-time overflow warning will be generated. > > [1] https://lore.kernel.org/linux-hardening/20220901065914.1417829-2-keescook@xxxxxxxxxxxx > > Cc: Maximilian Luz <luzmaximilian@xxxxxxxxx> > Cc: Hans de Goede <hdegoede@xxxxxxxxxx> > Cc: Mark Gross <markgross@xxxxxxxxxx> > Cc: platform-driver-x86@xxxxxxxxxxxxxxx > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> Thanks! -- Gustavo > --- > drivers/platform/surface/surface_acpi_notify.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/platform/surface/surface_acpi_notify.c b/drivers/platform/surface/surface_acpi_notify.c > index 44e317970557..50500e562963 100644 > --- a/drivers/platform/surface/surface_acpi_notify.c > +++ b/drivers/platform/surface/surface_acpi_notify.c > @@ -355,7 +355,8 @@ static u32 san_evt_bat_nf(struct ssam_event_notifier *nf, > INIT_DELAYED_WORK(&work->work, san_evt_bat_workfn); > work->dev = d->dev; > > - memcpy(&work->event, event, sizeof(struct ssam_event) + event->length); > + work->event = *event; > + memcpy(work->event.data, event->data, event->length); > > queue_delayed_work(san_wq, &work->work, delay); > return SSAM_NOTIF_HANDLED; > -- > 2.34.1 >
