From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 1DE03356754; Wed, 20 May 2026 16:28:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779294536; cv=none; b=f7cZlDNmPutb+I0G+pg9esgu25UTWkInsGbBFqMNVR81/qGc2LTeHllRBbY7ZFSsEw2H2txJnT6Lb/rxkP0lk9oV4T/8iMJpDXmA5lOp7TPlFr1Ii9SG0Awyd//N4u8ubB/K/sIU40etsx+FpCejbceC9G0/Wm2XfYB1Orh/SH8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779294536; c=relaxed/simple; bh=TiC+OBPymeKcDGPLCfrHQpBfgZJFicQQTvZ60amCTPE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=mKwPFNXhAKZzR3UB+QMYDsI+44hziyYjllsQeBbU4jarSOa+/Mb46NH7lMRNwKWcRtLuC3J05Sux+/E7Yv1AgSrirLrQJcd6vTV0nLTQqbxGMlBB/QAUtL2Pt0++yD4v40eVTofqZWKdUDtuH7ciRDScXdPFJSdflmRc6EkDDx8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=hGF+HT+c; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="hGF+HT+c" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5B7941F000E9; Wed, 20 May 2026 16:28:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779294534; bh=GR4szUdE+9ZHOEs3SqM2n+3bGd1tFFmo13DlLxb3gDE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=hGF+HT+cmHNmuTOMTnfgVIHuv/6DbfjAt5OtBaNp6iILjfOcZx/SxheLMdtpedKtd gbG47YRsEMoZFXsubKFL0V7art7j6JaN5Z8B1Cfoh22CW578fFCAW1heymclPw8zbz ig/3uEuxZLtjLWeZacPzRgb14tYbCXyOKC7tyjgU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Gui-Dong Han , =?UTF-8?q?Eugenio=20P=C3=A9rez?= , "Michael S. Tsirkin" , Danilo Krummrich , Sasha Levin Subject: [PATCH 7.0 0039/1146] vdpa: use generic driver_override infrastructure Date: Wed, 20 May 2026 18:04:49 +0200 Message-ID: <20260520162149.267015111@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162148.390695140@linuxfoundation.org> References: <20260520162148.390695140@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 7.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Danilo Krummrich [ Upstream commit 85bb534ff12aab6916058897b39c748940a7a4c6 ] 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") Acked-by: Eugenio Pérez Acked-by: Michael S. Tsirkin Link: https://patch.msgid.link/20260324005919.2408620-9-dakr@kernel.org Signed-off-by: Danilo Krummrich Signed-off-by: Sasha Levin --- 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 34874beb0152e..caf0ee5d6856c 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 2bfe3baa63f42..782c42d25db16 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