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 47D25408039; Tue, 21 Jul 2026 19:23:25 +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=1784661806; cv=none; b=ULXWUkfzylTPQwrNs2LbI7SIlABAIyPZXLMsd4scWCcD3mCibr3UNOHrqpg/RVNVOG0HRI+QR8xFCcaFJVJEKoVjzaolhgW/raW/hHfWHBLR9SryvhcW2sTCT4YTUgdoi/9mJBkDv+mfsyfvWlsiYEbDdOZyVPrnWKf69q+N08k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784661806; c=relaxed/simple; bh=WVDYg9f23B0N5udSZMWsNgz8WrKqaKPobQ/Wsz6nS3M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=V3+nbCc+ZRNsrDU2YvD9a5ZT5tOXeSFEq1Jg8corVVEC4NOLW27pGotqNb6NerKefRzeXPr31KiPg09Vmnh5Z9rR5tyX0YBSHXkb0A02x5OqzxFK7xFN0I3vkKU7FRJuZV/eRnLkNUTmFgIqMj84ZMOkluW5SpcsMPZlRtMyWVo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=o/WqlrFY; 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="o/WqlrFY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AD8221F000E9; Tue, 21 Jul 2026 19:23:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784661805; bh=XF9UkqGBIQICOtc9ZIsKCQF8uVkL76ek2YiJjAY5YwU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=o/WqlrFYD2wcJGZfxDwk+oEY3RVol88XGwB7AgD/9/wuj3u7UTulTLdInY/Za8BNE rVF6jvo09vvveWALSNAR1DZcviMUl7z1mmv9XROjVgs+eTLb2cC1UISQPZlMbU0iTW e1KmhAzg7vilXu8rxdCrNgsae3gYzhUOqlva7tXY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Michael Kelley , Gui-Dong Han , Danilo Krummrich , Sasha Levin Subject: [PATCH 6.12 0205/1276] Drivers: hv: vmbus: use generic driver_override infrastructure Date: Tue, 21 Jul 2026 17:10:48 +0200 Message-ID: <20260721152450.674520618@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152446.065700225@linuxfoundation.org> References: <20260721152446.065700225@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Danilo Krummrich [ Upstream commit 331d8900121a1d74ecd45cd2db742ddcb5a0a565 ] 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] Tested-by: Michael Kelley Reviewed-by: Michael Kelley 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") Reviewed-by: Greg Kroah-Hartman Link: https://patch.msgid.link/20260505133935.3772495-4-dakr@kernel.org Signed-off-by: Danilo Krummrich Signed-off-by: Sasha Levin --- drivers/hv/vmbus_drv.c | 43 ++++++++++-------------------------------- include/linux/hyperv.h | 5 ----- 2 files changed, 10 insertions(+), 38 deletions(-) diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 0191562e606d0c..83f3215bc5bd59 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -521,34 +521,6 @@ 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, @@ -579,7 +551,6 @@ 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, }; @@ -691,9 +662,11 @@ 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)) + /* If a driver override is set, only bind to the matching driver */ + ret = device_match_driver_override(&dev->device, &drv->driver); + if (ret == 0) return NULL; /* Look at the dynamic ids first, before the static ones */ @@ -701,8 +674,11 @@ static const struct hv_vmbus_device_id *hv_vmbus_get_id(const struct hv_driver * if (!id) id = hv_vmbus_dev_match(drv->id_table, guid); - /* driver_override will always match, send a dummy id */ - if (!id && dev->driver_override) + /* + * If there's a matching driver override, this function should succeed, + * thus return a dummy device ID if no matching ID is found. + */ + if (!id && ret > 0) id = &vmbus_device_null; return id; @@ -981,6 +957,7 @@ 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 44bf8af37901ba..2f40e2f40aa2c1 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1311,11 +1311,6 @@ 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