From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 73E761A6813; Tue, 24 Mar 2026 01:00:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774314011; cv=none; b=r+EOUq7uQbOsUzPJ+r4mPUipU1HmcPIOwNaq5RDFmapykApzsX18ybG3pT4y5V6bkOH0tupk0Nh0CUEItZg9Dc8vk+a7gz0RVo8PZQEl+3LUiZq7cIQHuiwnybmGhwuiM/NKwzwcl9vdUoT9cSSh8lcsy/t17wOYTAU6hRdFdfs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774314011; c=relaxed/simple; bh=n8Np19d6r8hZP3UfKo2xpfAW6SzD3g4bxMFuAspv2o0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=I47evUoeKybiw8OLEmSrA26mFzVnuIIDz1+08L3RYb7jGvj5CpcPq5DW9Wr/N143oZtyHRAlLsU7aY1qDs+VuK0E5lOMPTsepLecUqUK+2VH5VdAY0LHTUQFRbn4jlImJF1rbLySdOvvCqXIF5TwM4WGqIs8unCr5lax1QzboJA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UaBbnH6K; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UaBbnH6K" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 98196C4CEF7; Tue, 24 Mar 2026 01:00:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774314011; bh=n8Np19d6r8hZP3UfKo2xpfAW6SzD3g4bxMFuAspv2o0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UaBbnH6K5PmlHRTAv2QpnB7L6Oek7DpdNRyO3DZniaipx3T4OH8aQr0MWP23mO+nu bfEd7aSy90OVPMONjSRlDR+BhJep8zQkJXj3EuTj+FdEJ7Qnz1bGziLI/rD717BPhk b0qHoXuzvssQYxYxewY0RImhKrTnweUaP7b/G+xvgY86M3nL9h5A6viQlAO4cSYSa+ cTGrxdvuLF6cPLHkd8IEp6jriRalhcgoEWJdpC8TUtaMkApKMmASLxQKpBLi0FdDUk 0+jAHYnaXmU5F6R+YbNbusudC4hG0VrqpKsYsYuN7LhJINQFVJ9EqYYng4Ywg7RJ8h GAjkf9mQ3//og== From: Danilo Krummrich To: Russell King , Greg Kroah-Hartman , "Rafael J. Wysocki" , Ioana Ciornei , Nipun Gupta , Nikhil Agarwal , "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Long Li , Bjorn Helgaas , Armin Wolf , Bjorn Andersson , Mathieu Poirier , Vineeth Vijayan , Peter Oberparleiter , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Harald Freudenberger , Holger Dengler , Mark Brown , "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , =?UTF-8?q?Eugenio=20P=C3=A9rez?= , Alex Williamson , Juergen Gross , Stefano Stabellini , Oleksandr Tyshchenko , "Christophe Leroy (CS GROUP)" Cc: linux-kernel@vger.kernel.org, driver-core@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-hyperv@vger.kernel.org, linux-pci@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-s390@vger.kernel.org, linux-spi@vger.kernel.org, virtualization@lists.linux.dev, kvm@vger.kernel.org, xen-devel@lists.xenproject.org, linux-arm-kernel@lists.infradead.org, Danilo Krummrich , Gui-Dong Han Subject: [PATCH 04/12] hv: vmbus: use generic driver_override infrastructure Date: Tue, 24 Mar 2026 01:59:08 +0100 Message-ID: <20260324005919.2408620-5-dakr@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260324005919.2408620-1-dakr@kernel.org> References: <20260324005919.2408620-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit When a driver is probed through __driver_attach(), the bus' match() callback is called without the device lock held, thus accessing the driver_override field without a lock, which can cause a UAF. Fix this by using the driver-core driver_override infrastructure taking care of proper locking internally. Note that calling match() from __driver_attach() without the device lock held is intentional. [1] Link: https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/ [1] Reported-by: Gui-Dong Han Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220789 Fixes: d765edbb301c ("vmbus: add driver_override support") Signed-off-by: Danilo Krummrich --- drivers/hv/vmbus_drv.c | 36 +++++------------------------------- include/linux/hyperv.h | 5 ----- 2 files changed, 5 insertions(+), 36 deletions(-) diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index bc4fc1951ae1..bc8dfd136f3c 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -541,34 +541,6 @@ static ssize_t device_show(struct device *dev, } static DEVICE_ATTR_RO(device); -static ssize_t driver_override_store(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t count) -{ - struct hv_device *hv_dev = device_to_hv_device(dev); - int ret; - - ret = driver_set_override(dev, &hv_dev->driver_override, buf, count); - if (ret) - return ret; - - return count; -} - -static ssize_t driver_override_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct hv_device *hv_dev = device_to_hv_device(dev); - ssize_t len; - - device_lock(dev); - len = sysfs_emit(buf, "%s\n", hv_dev->driver_override); - device_unlock(dev); - - return len; -} -static DEVICE_ATTR_RW(driver_override); - /* Set up per device attributes in /sys/bus/vmbus/devices/ */ static struct attribute *vmbus_dev_attrs[] = { &dev_attr_id.attr, @@ -599,7 +571,6 @@ static struct attribute *vmbus_dev_attrs[] = { &dev_attr_channel_vp_mapping.attr, &dev_attr_vendor.attr, &dev_attr_device.attr, - &dev_attr_driver_override.attr, NULL, }; @@ -711,9 +682,11 @@ static const struct hv_vmbus_device_id *hv_vmbus_get_id(const struct hv_driver * { const guid_t *guid = &dev->dev_type; const struct hv_vmbus_device_id *id; + int ret; /* When driver_override is set, only bind to the matching driver */ - if (dev->driver_override && strcmp(dev->driver_override, drv->name)) + ret = device_match_driver_override(&dev->device, &drv->driver); + if (ret == 0) return NULL; /* Look at the dynamic ids first, before the static ones */ @@ -722,7 +695,7 @@ static const struct hv_vmbus_device_id *hv_vmbus_get_id(const struct hv_driver * id = hv_vmbus_dev_match(drv->id_table, guid); /* driver_override will always match, send a dummy id */ - if (!id && dev->driver_override) + if (!id && ret > 0) id = &vmbus_device_null; return id; @@ -1024,6 +997,7 @@ static const struct dev_pm_ops vmbus_pm = { /* The one and only one */ static const struct bus_type hv_bus = { .name = "vmbus", + .driver_override = true, .match = vmbus_match, .shutdown = vmbus_shutdown, .remove = vmbus_remove, diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index dfc516c1c719..bf689d07d750 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1272,11 +1272,6 @@ struct hv_device { u16 device_id; struct device device; - /* - * Driver name to force a match. Do not set directly, because core - * frees it. Use driver_set_override() to set or clear it. - */ - const char *driver_override; struct vmbus_channel *channel; struct kset *channels_kset; -- 2.53.0