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/input/misc/cpcap-pwrbutton.c | 112 +++++++++++++++++++++++++++++++++++ 1 file changed, 112 insertions(+) create mode 100644 drivers/input/misc/cpcap-pwrbutton.c (limited to 'drivers/input/misc/cpcap-pwrbutton.c') diff --git a/drivers/input/misc/cpcap-pwrbutton.c b/drivers/input/misc/cpcap-pwrbutton.c new file mode 100644 index 000000000..85cddb847 --- /dev/null +++ b/drivers/input/misc/cpcap-pwrbutton.c @@ -0,0 +1,112 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * CPCAP Power Button Input Driver + * + * Copyright (C) 2017 Sebastian Reichel + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define CPCAP_IRQ_ON 23 +#define CPCAP_IRQ_ON_BITMASK (1 << (CPCAP_IRQ_ON % 16)) + +struct cpcap_power_button { + struct regmap *regmap; + struct input_dev *idev; + struct device *dev; +}; + +static irqreturn_t powerbutton_irq(int irq, void *_button) +{ + struct cpcap_power_button *button = _button; + int val; + + val = cpcap_sense_virq(button->regmap, irq); + if (val < 0) { + dev_err(button->dev, "irq read failed: %d", val); + return IRQ_HANDLED; + } + + pm_wakeup_event(button->dev, 0); + input_report_key(button->idev, KEY_POWER, val); + input_sync(button->idev); + + return IRQ_HANDLED; +} + +static int cpcap_power_button_probe(struct platform_device *pdev) +{ + struct cpcap_power_button *button; + int irq; + int err; + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + button = devm_kmalloc(&pdev->dev, sizeof(*button), GFP_KERNEL); + if (!button) + return -ENOMEM; + + button->idev = devm_input_allocate_device(&pdev->dev); + if (!button->idev) + return -ENOMEM; + + button->regmap = dev_get_regmap(pdev->dev.parent, NULL); + if (!button->regmap) + return -ENODEV; + + button->dev = &pdev->dev; + + button->idev->name = "cpcap-pwrbutton"; + button->idev->phys = "cpcap-pwrbutton/input0"; + input_set_capability(button->idev, EV_KEY, KEY_POWER); + + err = devm_request_threaded_irq(&pdev->dev, irq, NULL, + powerbutton_irq, IRQF_ONESHOT, "cpcap_pwrbutton", button); + if (err < 0) { + dev_err(&pdev->dev, "IRQ request failed: %d\n", err); + return err; + } + + err = input_register_device(button->idev); + if (err) { + dev_err(&pdev->dev, "Input register failed: %d\n", err); + return err; + } + + device_init_wakeup(&pdev->dev, true); + + return 0; +} + +#ifdef CONFIG_OF +static const struct of_device_id cpcap_pwrbutton_dt_match_table[] = { + { .compatible = "motorola,cpcap-pwrbutton" }, + {}, +}; +MODULE_DEVICE_TABLE(of, cpcap_pwrbutton_dt_match_table); +#endif + +static struct platform_driver cpcap_power_button_driver = { + .probe = cpcap_power_button_probe, + .driver = { + .name = "cpcap-pwrbutton", + .of_match_table = of_match_ptr(cpcap_pwrbutton_dt_match_table), + }, +}; +module_platform_driver(cpcap_power_button_driver); + +MODULE_ALIAS("platform:cpcap-pwrbutton"); +MODULE_DESCRIPTION("CPCAP Power Button"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Sebastian Reichel "); -- cgit v1.3.1