Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751317Ab3HSR1p (ORCPT ); Mon, 19 Aug 2013 13:27:45 -0400 Received: from cavan.codon.org.uk ([93.93.128.6]:51131 "EHLO cavan.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750946Ab3HSR0V (ORCPT ); Mon, 19 Aug 2013 13:26:21 -0400 From: Matthew Garrett To: linux-kernel@vger.kernel.org Cc: linux-efi@vger.kernel.org, jwboyer@redhat.com, keescook@chromium.org, Matthew Garrett Subject: [PATCH V2 04/10] ACPI: Limit access to custom_method Date: Mon, 19 Aug 2013 13:26:05 -0400 Message-Id: <1376933171-9854-5-git-send-email-matthew.garrett@nebula.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1376933171-9854-1-git-send-email-matthew.garrett@nebula.com> References: <1376933171-9854-1-git-send-email-matthew.garrett@nebula.com> X-SA-Do-Not-Run: Yes X-SA-Exim-Connect-IP: 2001:470:1f07:1371:6267:20ff:fec3:2318 X-SA-Exim-Mail-From: matthew.garrett@nebula.com X-SA-Exim-Scanned: No (on cavan.codon.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1273 Lines: 39 custom_method effectively allows arbitrary access to system memory, making it possible for an attacker to circumvent restrictions on module loading. Disable it if any such restrictions have been enabled. Signed-off-by: Matthew Garrett --- drivers/acpi/custom_method.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/acpi/custom_method.c b/drivers/acpi/custom_method.c index 12b62f2..55a013f 100644 --- a/drivers/acpi/custom_method.c +++ b/drivers/acpi/custom_method.c @@ -7,6 +7,7 @@ #include #include #include +#include #include #include "internal.h" @@ -29,6 +30,9 @@ static ssize_t cm_write(struct file *file, const char __user * user_buf, struct acpi_table_header table; acpi_status status; + if (secure_modules()) + return -EPERM; + if (!(*ppos)) { /* parse the table header to get the table length */ if (count <= sizeof(struct acpi_table_header)) -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/