From: Kees Cook <keescook@chromium.org>
To: Maximilian Luz <luzmaximilian@gmail.com>
Cc: Kees Cook <keescook@chromium.org>,
Hans de Goede <hdegoede@redhat.com>,
Mark Gross <markgross@kernel.org>,
platform-driver-x86@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: [PATCH] platform/surface: Split memcpy() of struct ssam_event flexible array
Date: Mon, 26 Sep 2022 17:40:11 -0700 [thread overview]
Message-ID: <20220927004011.1942739-1-keescook@chromium.org> (raw)
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(-)
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
next reply other threads:[~2022-09-27 0:40 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-27 0:40 Kees Cook [this message]
2022-09-27 1:12 ` [PATCH] platform/surface: Split memcpy() of struct ssam_event flexible array Gustavo A. R. Silva
2022-09-27 11:17 ` Maximilian Luz
2022-09-27 13:15 ` Hans de Goede
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