From e873c74132f0c5f1452816cd9bb26208f0bba1e1 Mon Sep 17 00:00:00 2001 From: Shivank Garg Date: Sat, 22 Aug 2026 19:22:05 +0000 Subject: dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel() 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 Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com Reviewed-by: Frank Li Reviewed-by: Logan Gunthorpe Signed-off-by: Shivank Garg Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com Signed-off-by: Vinod Koul --- net/bluetooth/leds.c | 100 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 100 insertions(+) create mode 100644 net/bluetooth/leds.c (limited to 'net/bluetooth/leds.c') diff --git a/net/bluetooth/leds.c b/net/bluetooth/leds.c new file mode 100644 index 000000000..6e349704e --- /dev/null +++ b/net/bluetooth/leds.c @@ -0,0 +1,100 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2015, Heiner Kallweit + */ + +#include +#include + +#include "leds.h" + +DEFINE_LED_TRIGGER(bt_power_led_trigger); + +struct hci_basic_led_trigger { + struct led_trigger led_trigger; + struct hci_dev *hdev; +}; + +#define to_hci_basic_led_trigger(arg) container_of(arg, \ + struct hci_basic_led_trigger, led_trigger) + +void hci_leds_update_powered(struct hci_dev *hdev, bool enabled) +{ + if (hdev->power_led) + led_trigger_event(hdev->power_led, + enabled ? LED_FULL : LED_OFF); + + if (!enabled) { + struct hci_dev *d; + + read_lock(&hci_dev_list_lock); + + list_for_each_entry(d, &hci_dev_list, list) { + if (test_bit(HCI_UP, &d->flags)) + enabled = true; + } + + read_unlock(&hci_dev_list_lock); + } + + led_trigger_event(bt_power_led_trigger, enabled ? LED_FULL : LED_OFF); +} + +static int power_activate(struct led_classdev *led_cdev) +{ + struct hci_basic_led_trigger *htrig; + bool powered; + + htrig = to_hci_basic_led_trigger(led_cdev->trigger); + powered = test_bit(HCI_UP, &htrig->hdev->flags); + + led_set_brightness(led_cdev, powered ? LED_FULL : LED_OFF); + + return 0; +} + +static struct led_trigger *led_allocate_basic(struct hci_dev *hdev, + int (*activate)(struct led_classdev *led_cdev), + const char *name) +{ + struct hci_basic_led_trigger *htrig; + + htrig = devm_kzalloc(&hdev->dev, sizeof(*htrig), GFP_KERNEL); + if (!htrig) + return NULL; + + htrig->hdev = hdev; + htrig->led_trigger.activate = activate; + htrig->led_trigger.name = devm_kasprintf(&hdev->dev, GFP_KERNEL, + "%s-%s", hdev->name, + name); + if (!htrig->led_trigger.name) + goto err_alloc; + + if (devm_led_trigger_register(&hdev->dev, &htrig->led_trigger)) + goto err_register; + + return &htrig->led_trigger; + +err_register: + devm_kfree(&hdev->dev, (void *)htrig->led_trigger.name); +err_alloc: + devm_kfree(&hdev->dev, htrig); + return NULL; +} + +void hci_leds_init(struct hci_dev *hdev) +{ + /* initialize power_led */ + hdev->power_led = led_allocate_basic(hdev, power_activate, "power"); +} + +void bt_leds_init(void) +{ + led_trigger_register_simple("bluetooth-power", &bt_power_led_trigger); +} + +void bt_leds_cleanup(void) +{ + led_trigger_unregister_simple(bt_power_led_trigger); +} -- cgit v1.3.1