From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Wed, 20 Aug 2025 16:32:25 +0200 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1uojrW-002eF9-1S for lore@lore.pengutronix.de; Wed, 20 Aug 2025 16:32:25 +0200 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1uojrT-0006Ne-4P for lore@pengutronix.de; Wed, 20 Aug 2025 16:32:25 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:To:In-Reply-To:References: Message-Id:Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date: From:Reply-To:Cc:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=b/fJxrFjccB4wz6Ntkvs5NZIFVIjhe7+gWUFNfwWgoY=; b=iKQnm06UI853A+GNqAwrjWts3j N9e2cXfosHNG4oJp1qnWOM9V3xdJ62fj7CwE+Oc/JEniALaqohovN4yxJAtFDLDBFmdciioj0BgB7 29LoYBuFzK8QSMZOG50Mgi500w27WvkwWCJpV3npZgjSXOlUhX2OerS2YkVTqXdteUMFANZi2+MiH VPH1sDi91PnzO664TKzP+4N5EmnAiCtjbAdfMd8ntD++ebceYB1+fKJVVBMw1ljUoUGdlBfE3w4Yb W/zXdNiMnkKHsMYCnPlHTsniLbD2zl/P+RVCz7EPdHQNY9GHktNTjbKrIOw+uk3WrG5f51AqqfWgr IlV2/M/Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uojqv-0000000E4Mu-0RtK; Wed, 20 Aug 2025 14:31:49 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uoixI-0000000DoZY-3ss8 for barebox@lists.infradead.org; Wed, 20 Aug 2025 13:34:23 +0000 Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1uoixH-0003Ef-QB; Wed, 20 Aug 2025 15:34:19 +0200 Received: from dude02.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::28]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1uoixH-001FrX-1t; Wed, 20 Aug 2025 15:34:19 +0200 Received: from localhost ([::1] helo=dude02.red.stw.pengutronix.de) by dude02.red.stw.pengutronix.de with esmtp (Exim 4.96) (envelope-from ) id 1uoihK-004jSI-1r; Wed, 20 Aug 2025 15:17:50 +0200 From: Sascha Hauer Date: Wed, 20 Aug 2025 15:18:03 +0200 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20250820-security-policies-v1-19-76fde70fdbd8@pengutronix.de> References: <20250820-security-policies-v1-0-76fde70fdbd8@pengutronix.de> In-Reply-To: <20250820-security-policies-v1-0-76fde70fdbd8@pengutronix.de> To: BAREBOX X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1755695870; l=4769; i=s.hauer@pengutronix.de; s=20230412; h=from:subject:message-id; bh=VIf3qAqA6W2JZqnTnxDMQ75J6vHuGW6j1ggkcgvHOcM=; b=ZvsaTYeIeyrQ/bWB17GPZI9jf4NsxueORluKVX5m7FZUabOX7sJru9kOpFcNErCZtzdJ58+cC j5vn8O9JPG6DIKH1hrYejuxEOHgjafxtkU5tEoPvVeEA75+V5870xzL X-Developer-Key: i=s.hauer@pengutronix.de; a=ed25519; pk=4kuc9ocmECiBJKWxYgqyhtZOHj5AWi7+d0n/UjhkwTg= X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250820_063421_018138_C5EF9FCC X-CRM114-Status: GOOD ( 16.96 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.whiteo.stw.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-5.2 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: [PATCH 19/24] security: usbgadget: add usbgadget security policy X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.whiteo.stw.pengutronix.de) USB gadget might be considered dangerous in secure environments, so add a security policy for it. Signed-off-by: Sascha Hauer --- Sconfig | 1 + common/usbgadget.c | 26 ++++++++++++++++++++++++++ drivers/usb/gadget/Sconfig | 11 +++++++++++ drivers/usb/gadget/composite.c | 4 ++++ drivers/usb/gadget/legacy/serial.c | 4 ++++ 5 files changed, 46 insertions(+) diff --git a/Sconfig b/Sconfig index 899a1fb5783fb79def32e5af160b39208fea2edc..878d5055af2967617219cbadbfd8bee3f85236bd 100644 --- a/Sconfig +++ b/Sconfig @@ -6,4 +6,5 @@ source "scripts/Sconfig.include" source "security/Sconfig" source "common/Sconfig" +source "drivers/usb/gadget/Sconfig" source "commands/Sconfig" diff --git a/common/usbgadget.c b/common/usbgadget.c index 1333eaa413eafb766dc74e37e14d5082e93879ac..dc7b3ddc808ee0b1c63d81b914ff915bcc92a863 100644 --- a/common/usbgadget.c +++ b/common/usbgadget.c @@ -18,6 +18,7 @@ #include #include #include +#include static int autostart; static int nv_loaded; @@ -81,6 +82,9 @@ int usbgadget_register(struct f_multi_opts *opts) int ret; struct device *dev; + if (!IS_ALLOWED(SCONFIG_USB_GADGET)) + return -EPERM; + /* * Creating a gadget with both DFU and Fastboot may not work. * fastboot 1:8.1.0+r23-5 can deal with it, but dfu-util 0.9 @@ -106,6 +110,9 @@ int usbgadget_prepare_register(const struct usbgadget_funcs *funcs) struct f_multi_opts *opts; int ret; + if (!IS_ALLOWED(SCONFIG_USB_GADGET)) + return -EPERM; + opts = usbgadget_prepare(funcs); if (IS_ERR(opts)) return PTR_ERR(opts); @@ -161,6 +168,21 @@ void usbgadget_autostart(bool enable) usbgadget_do_autostart(); } +static void usbgadget_sconfig_update(struct sconfig_notifier_block *nb, + enum security_config_option opt, + bool allowed) +{ + if (allowed) { + if (autostart) + usbgadget_do_autostart(); + } else { + usb_multi_unregister(); + usb_serial_unregister(); + } +} + +static struct sconfig_notifier_block sconfig_notifier; + static int usbgadget_globalvars_init(void) { globalvar_add_simple_bool("usbgadget.acm", &acm); @@ -169,6 +191,10 @@ static int usbgadget_globalvars_init(void) globalvar_add_bool("usbgadget.autostart", usbgadget_autostart_set, &autostart, NULL); + sconfig_register_handler_filtered(&sconfig_notifier, + usbgadget_sconfig_update, + SCONFIG_USB_GADGET); + return 0; } coredevice_initcall(usbgadget_globalvars_init); diff --git a/drivers/usb/gadget/Sconfig b/drivers/usb/gadget/Sconfig new file mode 100644 index 0000000000000000000000000000000000000000..38797301e514c203f75f876fa54971846d39d292 --- /dev/null +++ b/drivers/usb/gadget/Sconfig @@ -0,0 +1,11 @@ + +menu "USB Gadget Policy" + +config USB_GADGET + bool "Allow USB gadget" + depends on $(kconfig-enabled,USB_GADGET) + help + USB gadget support might be potentially dangerous in secure environments. + The DFU and fastboot protocols allow to modify system partitions. + +endmenu diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c index 98f7b5bf7fb412b77f8a926375df3f0ffbbc96da..2a9984e37ad3ec1325822eb2d328481ceb3ff906 100644 --- a/drivers/usb/gadget/composite.c +++ b/drivers/usb/gadget/composite.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include @@ -2489,6 +2490,9 @@ int usb_composite_probe(struct usb_composite_driver *driver) { struct usb_gadget_driver *gadget_driver; + if (!IS_ALLOWED(SCONFIG_USB_GADGET)) + return -EPERM; + if (!driver || !driver->dev || !driver->bind) return -EINVAL; diff --git a/drivers/usb/gadget/legacy/serial.c b/drivers/usb/gadget/legacy/serial.c index 913d174a917794e7cab0f8006b8fd814887029f4..700e9db3a57462e331936efd303c6614544b251a 100644 --- a/drivers/usb/gadget/legacy/serial.c +++ b/drivers/usb/gadget/legacy/serial.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include "u_serial.h" @@ -253,6 +254,9 @@ int usb_serial_register(struct usb_serial_pdata *pdata) { int ret; + if (!IS_ALLOWED(SCONFIG_USB_GADGET)) + return -EPERM; + if (usb_serial_registered) { pr_err("USB serial gadget already registered\n"); return -EBUSY; -- 2.39.5