dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel()grafted

When dma_device_put() drops the last reference on chan->device->ref,
dma_device_release() runs and may free the dma_device along with its
channels.

dma_chan_put() then still reads chan->device->owner via
dma_chan_to_owner() for the trailing module_put(). KASAN catches it:

	slab-use-after-free in dma_chan_put+0x3e6/0x4c0
	Read of size 8 by task insmod/6319
	Freed by task 6319:
	  kfree+0x225/0x470
	  dma_chan_put+0x395/0x4c0
	  dmaengine_put+0xf8/0x160

Cache the module owner in dma_chan_put() before the put so the trailing
module_put() does not need chan->device.

Fixes: 8ad342a86359 ("dmaengine: Add reference counting to dma_device struct")
Suggested-by: Sashiko <sashiko-bot@kernel.org>
Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Shivank Garg <shivankg@amd.com>
Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

1 files changed, 98 insertions, 0 deletions

diff --git a/drivers/hid/hid-generic.c b/drivers/hid/hid-generic.c
new file mode 100644
index 000000000..c2de91674
--- /dev/null
+++ b/drivers/hid/hid-generic.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  HID support for Linux
+ *
+ *  Copyright (c) 1999 Andreas Gal
+ *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
+ *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
+ *  Copyright (c) 2007-2008 Oliver Neukum
+ *  Copyright (c) 2006-2012 Jiri Kosina
+ *  Copyright (c) 2012 Henrik Rydberg
+ */
+
+/*
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/unaligned.h>
+#include <asm/byteorder.h>
+
+#include <linux/hid.h>
+
+static struct hid_driver hid_generic;
+
+static int __check_hid_generic(struct device_driver *drv, void *data)
+{
+	struct hid_driver *hdrv = to_hid_driver(drv);
+	struct hid_device *hdev = data;
+
+	if (hdrv == &hid_generic)
+		return 0;
+
+	return hid_match_device(hdev, hdrv) != NULL;
+}
+
+static bool hid_generic_match(struct hid_device *hdev,
+			      bool ignore_special_driver)
+{
+	if (ignore_special_driver)
+		return true;
+
+	if (hdev->quirks & HID_QUIRK_IGNORE_SPECIAL_DRIVER)
+		return true;
+
+	if (hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER)
+		return false;
+
+	/*
+	 * If any other driver wants the device, leave the device to this other
+	 * driver.
+	 */
+	if (bus_for_each_drv(&hid_bus_type, NULL, hdev, __check_hid_generic))
+		return false;
+
+	return true;
+}
+
+static int hid_generic_probe(struct hid_device *hdev,
+			     const struct hid_device_id *id)
+{
+	int ret;
+
+	hdev->quirks |= HID_QUIRK_INPUT_PER_APP;
+
+	ret = hid_parse(hdev);
+	if (ret)
+		return ret;
+
+	return hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+}
+
+static int hid_generic_reset_resume(struct hid_device *hdev)
+{
+	if (hdev->claimed & HID_CLAIMED_INPUT)
+		hidinput_reset_resume(hdev);
+
+	return 0;
+}
+
+static const struct hid_device_id hid_table[] = {
+	{ HID_DEVICE(HID_BUS_ANY, HID_GROUP_ANY, HID_ANY_ID, HID_ANY_ID) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, hid_table);
+
+static struct hid_driver hid_generic = {
+	.name = "hid-generic",
+	.id_table = hid_table,
+	.match = hid_generic_match,
+	.probe = hid_generic_probe,
+	.reset_resume = hid_generic_reset_resume,
+};
+module_hid_driver(hid_generic);
+
+MODULE_AUTHOR("Henrik Rydberg");
+MODULE_DESCRIPTION("HID generic driver");
+MODULE_LICENSE("GPL");