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 B67C6471401; Tue, 21 Jul 2026 17:51:34 +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=1784656295; cv=none; b=SlwrEYALVClTYESozQAI3//mlrVgwfmXRhjJ8RGsvGX4JqVdTwuCYYpCtyGNVlUJ9Czr5bbTPeLHyqvNM76FrO4BaqScMu9/QQuFzK9cXWIgiwFLmCe/RO2pvNqjW2z48A4gf/aRXvh+KskNytU4smKZYzHwvAyGCkkzx/sXkS8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784656295; c=relaxed/simple; bh=9/8bTIlvb/CC3BmkTJh9B5gEC3h66A6q4Wugp8kubxM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kEMp8RsCS36xjdiedjPL3p9OMcvpg/Pcj8R3/flq3h2MaOmK+zz8xCLX7pQ2daC0Kkn2P+72LCYaBTVQNSJB5dJKIenF/rAgVlq5umGkn/tRgxkD0rtMEdlFPUqclg2b8MJqcKCaMtjYM//Ex+JzEiwfvMHAErsee3bvZAtp2PU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ItkxYJjL; 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="ItkxYJjL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 283101F000E9; Tue, 21 Jul 2026 17:51:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784656294; bh=mn9UUbzWDu404IuyPVZRakYF9xcO+5bv7+BF32ZUJwg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ItkxYJjL06hovThKhd6DdgApC2ItI0IogIwE2Rrc1Fwoc9hDLXn42LIlyy6hjAXpZ dmHewSuABNmjpsXlDGh3ynljRcU8VMfNFC+B3LoCz9vN4Kdlbp3G5RWIj7rr8oJ1ax TKLUMCI1exq5AqVGdzwl7dXwE/MM7Meh1/p7x2pg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Gui-Dong Han , Danilo Krummrich , Sasha Levin Subject: [PATCH 6.18 0280/1611] cdx: use generic driver_override infrastructure Date: Tue, 21 Jul 2026 17:06:36 +0200 Message-ID: <20260721152521.353888928@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 d541aa1897f67f4f14c805785bff894bcc61dca1 ] 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: 2959ab247061 ("cdx: add the cdx bus driver") Reviewed-by: Greg Kroah-Hartman Link: https://patch.msgid.link/20260505133935.3772495-3-dakr@kernel.org Signed-off-by: Danilo Krummrich Signed-off-by: Sasha Levin --- drivers/cdx/cdx.c | 40 +++++-------------------------------- include/linux/cdx/cdx_bus.h | 4 ---- 2 files changed, 5 insertions(+), 39 deletions(-) diff --git a/drivers/cdx/cdx.c b/drivers/cdx/cdx.c index 3d50f8cd9c0bd7..9d6d24f49938b3 100644 --- a/drivers/cdx/cdx.c +++ b/drivers/cdx/cdx.c @@ -156,8 +156,6 @@ static int cdx_unregister_device(struct device *dev, } else { cdx_destroy_res_attr(cdx_dev, MAX_CDX_DEV_RESOURCES); debugfs_remove_recursive(cdx_dev->debugfs_dir); - kfree(cdx_dev->driver_override); - cdx_dev->driver_override = NULL; } /* @@ -268,6 +266,7 @@ static int cdx_bus_match(struct device *dev, const struct device_driver *drv) const struct cdx_driver *cdx_drv = to_cdx_driver(drv); const struct cdx_device_id *found_id = NULL; const struct cdx_device_id *ids; + int ret; if (cdx_dev->is_bus) return false; @@ -275,7 +274,8 @@ static int cdx_bus_match(struct device *dev, const struct device_driver *drv) ids = cdx_drv->match_id_table; /* When driver_override is set, only bind to the matching driver */ - if (cdx_dev->driver_override && strcmp(cdx_dev->driver_override, drv->name)) + ret = device_match_driver_override(dev, drv); + if (ret == 0) return false; found_id = cdx_match_id(ids, cdx_dev); @@ -289,7 +289,7 @@ static int cdx_bus_match(struct device *dev, const struct device_driver *drv) */ if (!found_id->override_only) return true; - if (cdx_dev->driver_override) + if (ret > 0) return true; ids = found_id + 1; @@ -453,36 +453,6 @@ static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR_RO(modalias); -static ssize_t driver_override_store(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t count) -{ - struct cdx_device *cdx_dev = to_cdx_device(dev); - int ret; - - if (WARN_ON(dev->bus != &cdx_bus_type)) - return -EINVAL; - - ret = driver_set_override(dev, &cdx_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 cdx_device *cdx_dev = to_cdx_device(dev); - ssize_t len; - - device_lock(dev); - len = sysfs_emit(buf, "%s\n", cdx_dev->driver_override); - device_unlock(dev); - return len; -} -static DEVICE_ATTR_RW(driver_override); - static ssize_t enable_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { @@ -552,7 +522,6 @@ static struct attribute *cdx_dev_attrs[] = { &dev_attr_class.attr, &dev_attr_revision.attr, &dev_attr_modalias.attr, - &dev_attr_driver_override.attr, NULL, }; @@ -653,6 +622,7 @@ ATTRIBUTE_GROUPS(cdx_bus); struct bus_type cdx_bus_type = { .name = "cdx", + .driver_override = true, .match = cdx_bus_match, .probe = cdx_probe, .remove = cdx_remove, diff --git a/include/linux/cdx/cdx_bus.h b/include/linux/cdx/cdx_bus.h index 79bb80e5679083..527f8851f0cde9 100644 --- a/include/linux/cdx/cdx_bus.h +++ b/include/linux/cdx/cdx_bus.h @@ -137,9 +137,6 @@ struct cdx_controller { * @enabled: is this bus enabled * @msi_dev_id: MSI Device ID associated with CDX device * @num_msi: Number of MSI's supported by the device - * @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. * @irqchip_lock: lock to synchronize irq/msi configuration * @msi_write_pending: MSI write pending for this device */ @@ -165,7 +162,6 @@ struct cdx_device { bool enabled; u32 msi_dev_id; u32 num_msi; - const char *driver_override; struct mutex irqchip_lock; bool msi_write_pending; }; -- 2.53.0