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 197C1373BF8; Tue, 24 Mar 2026 01:00:49 +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=1774314050; cv=none; b=tEvHq1M4zapJbmdsBPLyNQKBV46y6MeVg4IH1og9fPlM3hOXXEdKH+8uTvnQtM/4/M1OPjuT8Prb9sTJv23MraheIMLWSbqOOpg5b5gh8TKzJjS2aJs8a932KiCuewB/NCMWcdBQBKVXl4+MdYQYs+aEGwnoKEE1b2/2yZTV5DI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774314050; c=relaxed/simple; bh=2lHhdrgE9qzH1ZdWMWGXkZLiIUExSh17kxoWzoBpEYw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tn4r10MH46SBtv2c/Ly9ouNQ+DCFU5PLIbMOO+I/8Cy9zHin/0o5gt2VN9u+gLdJoPovI8eN/pSCeFd5TuV98w4uTLqcL/1tODJp5XE5nWdI7Nuz/99vIo+8inwxCVIHWPycS0rJK2M8giSLlHDK4v63QKa7vtW5G/TwOYvUgtc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=urbkSyPC; 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="urbkSyPC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 600FAC2BCB3; Tue, 24 Mar 2026 01:00:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774314049; bh=2lHhdrgE9qzH1ZdWMWGXkZLiIUExSh17kxoWzoBpEYw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=urbkSyPC//Mc+7xDMT60BWD1PM5iJno/Pv3C12Ww9BFBlm+Txslon6hgVop799Zux g+Sv+q81mxYoKpArwgNlL1ZLxKeJEZHi/lM3U9lsj91wt+dVuwPQVluFb1QQ+HQlCj sv5wTpgn5xlflwnnmanQE9E5F/Pn2wr+wAILRhGodQgtrhj4oxFDHJG9NtY75ERcHC m7A8DB8J2Ne77LkVgV0/eIo9dU9uCfUYKNhjjLT4Tt3E8Clc0+8oqnyAcHS/Bg4R5L D1zJWmU8m174lSqL3A0Ubvc3fqLrq3bwEdahRa42TfG/CVeZDK4Hwt1j/T6kr4aNVX 9oiBCcvJ5IK1g== 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 08/12] vdpa: use generic driver_override infrastructure Date: Tue, 24 Mar 2026 01:59:12 +0100 Message-ID: <20260324005919.2408620-9-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: 539fec78edb4 ("vdpa: add driver_override support") Signed-off-by: Danilo Krummrich --- drivers/vdpa/vdpa.c | 48 +++++--------------------------------------- include/linux/vdpa.h | 4 ---- 2 files changed, 5 insertions(+), 47 deletions(-) diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c index 34874beb0152..caf0ee5d6856 100644 --- a/drivers/vdpa/vdpa.c +++ b/drivers/vdpa/vdpa.c @@ -67,57 +67,20 @@ static void vdpa_dev_remove(struct device *d) static int vdpa_dev_match(struct device *dev, const struct device_driver *drv) { - struct vdpa_device *vdev = dev_to_vdpa(dev); + int ret; /* Check override first, and if set, only use the named driver */ - if (vdev->driver_override) - return strcmp(vdev->driver_override, drv->name) == 0; + ret = device_match_driver_override(dev, drv); + if (ret >= 0) + return ret; /* Currently devices must be supported by all vDPA bus drivers */ return 1; } -static ssize_t driver_override_store(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t count) -{ - struct vdpa_device *vdev = dev_to_vdpa(dev); - int ret; - - ret = driver_set_override(dev, &vdev->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 vdpa_device *vdev = dev_to_vdpa(dev); - ssize_t len; - - device_lock(dev); - len = sysfs_emit(buf, "%s\n", vdev->driver_override); - device_unlock(dev); - - return len; -} -static DEVICE_ATTR_RW(driver_override); - -static struct attribute *vdpa_dev_attrs[] = { - &dev_attr_driver_override.attr, - NULL, -}; - -static const struct attribute_group vdpa_dev_group = { - .attrs = vdpa_dev_attrs, -}; -__ATTRIBUTE_GROUPS(vdpa_dev); - static const struct bus_type vdpa_bus = { .name = "vdpa", - .dev_groups = vdpa_dev_groups, + .driver_override = true, .match = vdpa_dev_match, .probe = vdpa_dev_probe, .remove = vdpa_dev_remove, @@ -132,7 +95,6 @@ static void vdpa_release_dev(struct device *d) ops->free(vdev); ida_free(&vdpa_index_ida, vdev->index); - kfree(vdev->driver_override); kfree(vdev); } diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h index 2bfe3baa63f4..782c42d25db1 100644 --- a/include/linux/vdpa.h +++ b/include/linux/vdpa.h @@ -72,9 +72,6 @@ struct vdpa_mgmt_dev; * struct vdpa_device - representation of a vDPA device * @dev: underlying device * @vmap: the metadata passed to upper layer to be used for mapping - * @driver_override: driver name to force a match; do not set directly, - * because core frees it; use driver_set_override() to - * set or clear it. * @config: the configuration ops for this device. * @map: the map ops for this device * @cf_lock: Protects get and set access to configuration layout. @@ -90,7 +87,6 @@ struct vdpa_mgmt_dev; struct vdpa_device { struct device dev; union virtio_map vmap; - const char *driver_override; const struct vdpa_config_ops *config; const struct virtio_map_ops *map; struct rw_semaphore cf_lock; /* Protects get/set config */ -- 2.53.0