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 D3F8046D082; Tue, 21 Jul 2026 17:49:35 +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=1784656177; cv=none; b=WqgkKARkXFhcnLhYCI5FrnzVtUeswykyW2Sw4RTFXyfKLUfn6bzbz51mIXgMYrgJK9jWeGEfePEOLy9ZSa6qM+bMHjcJG4WlooupJO75oNZQh8hi6vIHxVi9TbYPzXX76bwanD0EyExxgOHNYr6mFVD3xgL5yVSJoEgyFHeIuJg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784656177; c=relaxed/simple; bh=9aPpvn8VbN+9V7AmWHOqOtdGteEGlWZ4uawz7aGs6VI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=twG2R7yenrg/PJzgOlHv8okI3tvKBTz9iGtIJd2ujkjRQeBDfp2nTN+sagt+rFiXh0WdEq1fa1NrKcmPXB0OercRXNKnyNkUFsSPN5EM5EUd7dv88h+0PUm7+l4tVim4Wn2GVfXh7tZsJYlFDseNDpVgoAnrag8jz3fJJEX+9+U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=yu55AOBd; 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="yu55AOBd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 45D351F000E9; Tue, 21 Jul 2026 17:49:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784656175; bh=LGVYVsQxjjn8zwchSool2+m1dptS6WUytcSSzymOtro=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=yu55AOBdzkHLMOeqkxEm1b5D+SsyNej9TvOoFPb630+LaTjndy3QI5bFHtstuxPp7 dc1gorzI8vHyP1Ke76rYBy7US1HXt2IJ+FJIa22b9vDRWENPbAmLTIoxk0JB85fCtn sW3IEXa0eLlV8ZATG3u7gzp7UgDFUNvM0lGBvRRA= 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 6.18 0281/1611] Drivers: hv: vmbus: use generic driver_override infrastructure Date: Tue, 21 Jul 2026 17:06:37 +0200 Message-ID: <20260721152521.377017931@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152514.750365251@linuxfoundation.org> References: <20260721152514.750365251@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 6.18-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 137cf82e2292ec..1a0e350c19404d 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -550,34 +550,6 @@ 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, @@ -608,7 +580,6 @@ 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, }; @@ -720,9 +691,11 @@ 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 */ @@ -730,8 +703,11 @@ 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; @@ -1033,6 +1009,7 @@ 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 b0502a336eb3a5..be9946a2cff2ad 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