| Message ID | 20220927004011.1942739-1-keescook@chromium.org (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | a776bf77c98ddea32233e2480f565797900975ba |
| Headers | show |
| Series | platform/surface: Split memcpy() of struct ssam_event flexible array | expand |
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@chromium.org > > Cc: Maximilian Luz <luzmaximilian@gmail.com> > Cc: Hans de Goede <hdegoede@redhat.com> > Cc: Mark Gross <markgross@kernel.org> > Cc: platform-driver-x86@vger.kernel.org > Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> 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 >
On 9/27/22 02:40, 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@chromium.org > > Cc: Maximilian Luz <luzmaximilian@gmail.com> > Cc: Hans de Goede <hdegoede@redhat.com> > Cc: Mark Gross <markgross@kernel.org> > Cc: platform-driver-x86@vger.kernel.org > Signed-off-by: Kees Cook <keescook@chromium.org> Thanks! Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com> Regards, Max > --- > 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;
Hi, On 9/27/22 02:40, 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@chromium.org > > Cc: Maximilian Luz <luzmaximilian@gmail.com> > Cc: Hans de Goede <hdegoede@redhat.com> > Cc: Mark Gross <markgross@kernel.org> > Cc: platform-driver-x86@vger.kernel.org > Signed-off-by: Kees Cook <keescook@chromium.org> Thank you for your patch, I've applied this patch to my review-hans branch: https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans Note it will show up in my review-hans branch once I've pushed my local branch there, which might take a while. Once I've run some tests on this branch the patches there will be added to the platform-drivers-x86/for-next branch and eventually will be included in the pdx86 pull-request to Linus for the next merge-window. Regards, Hans > --- > 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;
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;
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@chromium.org Cc: Maximilian Luz <luzmaximilian@gmail.com> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Mark Gross <markgross@kernel.org> Cc: platform-driver-x86@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> --- drivers/platform/surface/surface_acpi_notify.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)