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 --- drivers/usb/common/led.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 drivers/usb/common/led.c (limited to 'drivers/usb/common/led.c') diff --git a/drivers/usb/common/led.c b/drivers/usb/common/led.c new file mode 100644 index 000000000..1de18d90b --- /dev/null +++ b/drivers/usb/common/led.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * LED Triggers for USB Activity + * + * Copyright 2014 Michal Sojka + */ + +#include +#include +#include +#include +#include +#include "common.h" + +#define BLINK_DELAY 30 + +DEFINE_LED_TRIGGER(ledtrig_usb_gadget); +DEFINE_LED_TRIGGER(ledtrig_usb_host); + +void usb_led_activity(enum usb_led_event ev) +{ + struct led_trigger *trig = NULL; + + switch (ev) { + case USB_LED_EVENT_GADGET: + trig = ledtrig_usb_gadget; + break; + case USB_LED_EVENT_HOST: + trig = ledtrig_usb_host; + break; + } + /* led_trigger_blink_oneshot() handles trig == NULL gracefully */ + led_trigger_blink_oneshot(trig, BLINK_DELAY, BLINK_DELAY, 0); +} +EXPORT_SYMBOL_GPL(usb_led_activity); + + +void __init ledtrig_usb_init(void) +{ + led_trigger_register_simple("usb-gadget", &ledtrig_usb_gadget); + led_trigger_register_simple("usb-host", &ledtrig_usb_host); +} + +void __exit ledtrig_usb_exit(void) +{ + led_trigger_unregister_simple(ledtrig_usb_gadget); + led_trigger_unregister_simple(ledtrig_usb_host); +} -- cgit v1.3.1