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/touchscreen/dynapro.c | 185 ++++++++++++++++++++++++++++++++++++ 1 file changed, 185 insertions(+) create mode 100644 drivers/input/touchscreen/dynapro.c (limited to 'drivers/input/touchscreen/dynapro.c') diff --git a/drivers/input/touchscreen/dynapro.c b/drivers/input/touchscreen/dynapro.c new file mode 100644 index 000000000..943ba8c2f --- /dev/null +++ b/drivers/input/touchscreen/dynapro.c @@ -0,0 +1,185 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Dynapro serial touchscreen driver + * + * Copyright (c) 2009 Tias Guns + * Based on the inexio driver (c) Vojtech Pavlik and Dan Streetman and + * Richard Lemon + */ + + +/* + * 2009/09/19 Tias Guns + * Copied inexio.c and edited for Dynapro protocol (from retired Xorg module) + */ + +#include +#include +#include +#include +#include +#include + +#define DRIVER_DESC "Dynapro serial touchscreen driver" + +MODULE_AUTHOR("Tias Guns "); +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_LICENSE("GPL"); + +/* + * Definitions & global arrays. + */ + +#define DYNAPRO_FORMAT_TOUCH_BIT 0x40 +#define DYNAPRO_FORMAT_LENGTH 3 +#define DYNAPRO_RESPONSE_BEGIN_BYTE 0x80 + +#define DYNAPRO_MIN_XC 0 +#define DYNAPRO_MAX_XC 0x3ff +#define DYNAPRO_MIN_YC 0 +#define DYNAPRO_MAX_YC 0x3ff + +#define DYNAPRO_GET_XC(data) (data[1] | ((data[0] & 0x38) << 4)) +#define DYNAPRO_GET_YC(data) (data[2] | ((data[0] & 0x07) << 7)) +#define DYNAPRO_GET_TOUCHED(data) (DYNAPRO_FORMAT_TOUCH_BIT & data[0]) + +/* + * Per-touchscreen data. + */ + +struct dynapro { + struct input_dev *dev; + struct serio *serio; + int idx; + unsigned char data[DYNAPRO_FORMAT_LENGTH]; + char phys[32]; +}; + +static void dynapro_process_data(struct dynapro *pdynapro) +{ + struct input_dev *dev = pdynapro->dev; + + if (DYNAPRO_FORMAT_LENGTH == ++pdynapro->idx) { + input_report_abs(dev, ABS_X, DYNAPRO_GET_XC(pdynapro->data)); + input_report_abs(dev, ABS_Y, DYNAPRO_GET_YC(pdynapro->data)); + input_report_key(dev, BTN_TOUCH, + DYNAPRO_GET_TOUCHED(pdynapro->data)); + input_sync(dev); + + pdynapro->idx = 0; + } +} + +static irqreturn_t dynapro_interrupt(struct serio *serio, + unsigned char data, unsigned int flags) +{ + struct dynapro *pdynapro = serio_get_drvdata(serio); + + pdynapro->data[pdynapro->idx] = data; + + if (DYNAPRO_RESPONSE_BEGIN_BYTE & pdynapro->data[0]) + dynapro_process_data(pdynapro); + else + dev_dbg(&serio->dev, "unknown/unsynchronized data: %x\n", + pdynapro->data[0]); + + return IRQ_HANDLED; +} + +static void dynapro_disconnect(struct serio *serio) +{ + struct dynapro *pdynapro = serio_get_drvdata(serio); + + input_get_device(pdynapro->dev); + input_unregister_device(pdynapro->dev); + serio_close(serio); + serio_set_drvdata(serio, NULL); + input_put_device(pdynapro->dev); + kfree(pdynapro); +} + +/* + * dynapro_connect() is the routine that is called when someone adds a + * new serio device that supports dynapro protocol and registers it as + * an input device. This is usually accomplished using inputattach. + */ + +static int dynapro_connect(struct serio *serio, struct serio_driver *drv) +{ + struct dynapro *pdynapro; + struct input_dev *input_dev; + int err; + + pdynapro = kzalloc_obj(*pdynapro); + input_dev = input_allocate_device(); + if (!pdynapro || !input_dev) { + err = -ENOMEM; + goto fail1; + } + + pdynapro->serio = serio; + pdynapro->dev = input_dev; + scnprintf(pdynapro->phys, sizeof(pdynapro->phys), + "%s/input0", serio->phys); + + input_dev->name = "Dynapro Serial TouchScreen"; + input_dev->phys = pdynapro->phys; + input_dev->id.bustype = BUS_RS232; + input_dev->id.vendor = SERIO_DYNAPRO; + input_dev->id.product = 0; + input_dev->id.version = 0x0001; + input_dev->dev.parent = &serio->dev; + input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); + input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); + input_set_abs_params(pdynapro->dev, ABS_X, + DYNAPRO_MIN_XC, DYNAPRO_MAX_XC, 0, 0); + input_set_abs_params(pdynapro->dev, ABS_Y, + DYNAPRO_MIN_YC, DYNAPRO_MAX_YC, 0, 0); + + serio_set_drvdata(serio, pdynapro); + + err = serio_open(serio, drv); + if (err) + goto fail2; + + err = input_register_device(pdynapro->dev); + if (err) + goto fail3; + + return 0; + + fail3: serio_close(serio); + fail2: serio_set_drvdata(serio, NULL); + fail1: input_free_device(input_dev); + kfree(pdynapro); + return err; +} + +/* + * The serio driver structure. + */ + +static const struct serio_device_id dynapro_serio_ids[] = { + { + .type = SERIO_RS232, + .proto = SERIO_DYNAPRO, + .id = SERIO_ANY, + .extra = SERIO_ANY, + }, + { 0 } +}; + +MODULE_DEVICE_TABLE(serio, dynapro_serio_ids); + +static struct serio_driver dynapro_drv = { + .driver = { + .name = "dynapro", + }, + .description = DRIVER_DESC, + .id_table = dynapro_serio_ids, + .interrupt = dynapro_interrupt, + .connect = dynapro_connect, + .disconnect = dynapro_disconnect, +}; + +module_serio_driver(dynapro_drv); -- cgit v1.3.1