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, 85 insertions, 0 deletions

diff --git a/drivers/hid/hid-input-test.c b/drivers/hid/hid-input-test.c
new file mode 100644
index 000000000..c92008daf
--- /dev/null
+++ b/drivers/hid/hid-input-test.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  HID to Linux Input mapping
+ *
+ *  Copyright (c) 2022 José Expósito <jose.exposito89@gmail.com>
+ */
+
+#include <kunit/test.h>
+
+static void hid_test_input_update_battery_charge_status(struct kunit *test)
+{
+	struct hid_battery *bat;
+	bool handled;
+
+	bat = kunit_kzalloc(test, sizeof(*bat), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bat);
+
+	handled = hidinput_update_battery_charge_status(bat, HID_DG_HEIGHT, 0);
+	KUNIT_EXPECT_FALSE(test, handled);
+	KUNIT_EXPECT_EQ(test, bat->charge_status, POWER_SUPPLY_STATUS_UNKNOWN);
+
+	handled = hidinput_update_battery_charge_status(bat, HID_BAT_CHARGING, 0);
+	KUNIT_EXPECT_TRUE(test, handled);
+	KUNIT_EXPECT_EQ(test, bat->charge_status, POWER_SUPPLY_STATUS_DISCHARGING);
+
+	handled = hidinput_update_battery_charge_status(bat, HID_BAT_CHARGING, 1);
+	KUNIT_EXPECT_TRUE(test, handled);
+	KUNIT_EXPECT_EQ(test, bat->charge_status, POWER_SUPPLY_STATUS_CHARGING);
+}
+
+static void hid_test_input_get_battery_property(struct kunit *test)
+{
+	struct power_supply *psy;
+	struct hid_battery *bat;
+	struct hid_device *dev;
+	union power_supply_propval val;
+	int ret;
+
+	dev = kunit_kzalloc(test, sizeof(*dev), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dev);
+
+	bat = kunit_kzalloc(test, sizeof(*bat), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bat);
+	bat->dev = dev;
+	bat->avoid_query = true;
+
+	psy = kunit_kzalloc(test, sizeof(*psy), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, psy);
+	psy->drv_data = bat;
+
+	bat->status = HID_BATTERY_UNKNOWN;
+	bat->charge_status = POWER_SUPPLY_STATUS_CHARGING;
+	ret = hidinput_get_battery_property(psy, POWER_SUPPLY_PROP_STATUS, &val);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, val.intval, POWER_SUPPLY_STATUS_UNKNOWN);
+
+	bat->status = HID_BATTERY_REPORTED;
+	bat->charge_status = POWER_SUPPLY_STATUS_CHARGING;
+	ret = hidinput_get_battery_property(psy, POWER_SUPPLY_PROP_STATUS, &val);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, val.intval, POWER_SUPPLY_STATUS_CHARGING);
+
+	bat->status = HID_BATTERY_REPORTED;
+	bat->charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
+	ret = hidinput_get_battery_property(psy, POWER_SUPPLY_PROP_STATUS, &val);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, val.intval, POWER_SUPPLY_STATUS_DISCHARGING);
+}
+
+static struct kunit_case hid_input_tests[] = {
+	KUNIT_CASE(hid_test_input_update_battery_charge_status),
+	KUNIT_CASE(hid_test_input_get_battery_property),
+	{ }
+};
+
+static struct kunit_suite hid_input_test_suite = {
+	.name = "hid_input",
+	.test_cases = hid_input_tests,
+};
+
+kunit_test_suite(hid_input_test_suite);
+
+MODULE_DESCRIPTION("HID input KUnit tests");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("José Expósito <jose.exposito89@gmail.com>");