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/base/pinctrl.c | 107 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 107 insertions(+) create mode 100644 drivers/base/pinctrl.c (limited to 'drivers/base/pinctrl.c') diff --git a/drivers/base/pinctrl.c b/drivers/base/pinctrl.c new file mode 100644 index 000000000..0bbc83231 --- /dev/null +++ b/drivers/base/pinctrl.c @@ -0,0 +1,107 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Driver core interface to the pinctrl subsystem. + * + * Copyright (C) 2012 ST-Ericsson SA + * Written on behalf of Linaro for ST-Ericsson + * Based on bits of regulator core, gpio core and clk core + * + * Author: Linus Walleij + */ + +#include +#include +#include +#include + +#include "base.h" + +/** + * pinctrl_bind_pins() - called by the device core before probe + * @dev: the device that is just about to probe + */ +int pinctrl_bind_pins(struct device *dev) +{ + int ret; + + if (dev_of_node_reused(dev)) + return 0; + + dev->pins = devm_kzalloc(dev, sizeof(*(dev->pins)), GFP_KERNEL); + if (!dev->pins) + return -ENOMEM; + + dev->pins->p = devm_pinctrl_get(dev); + if (IS_ERR(dev->pins->p)) { + dev_dbg(dev, "no pinctrl handle\n"); + ret = PTR_ERR(dev->pins->p); + goto cleanup_alloc; + } + + dev->pins->default_state = pinctrl_lookup_state(dev->pins->p, + PINCTRL_STATE_DEFAULT); + if (IS_ERR(dev->pins->default_state)) { + dev_dbg(dev, "no default pinctrl state\n"); + ret = 0; + goto cleanup_get; + } + + dev->pins->init_state = pinctrl_lookup_state(dev->pins->p, + PINCTRL_STATE_INIT); + if (IS_ERR(dev->pins->init_state)) { + /* Not supplying this state is perfectly legal */ + dev_dbg(dev, "no init pinctrl state\n"); + + ret = pinctrl_select_state(dev->pins->p, + dev->pins->default_state); + } else { + ret = pinctrl_select_state(dev->pins->p, dev->pins->init_state); + } + + if (ret) { + dev_dbg(dev, "failed to activate initial pinctrl state\n"); + goto cleanup_get; + } + +#ifdef CONFIG_PM + /* + * If power management is enabled, we also look for the optional + * sleep and idle pin states, with semantics as defined in + * + */ + dev->pins->sleep_state = pinctrl_lookup_state(dev->pins->p, + PINCTRL_STATE_SLEEP); + if (IS_ERR(dev->pins->sleep_state)) + /* Not supplying this state is perfectly legal */ + dev_dbg(dev, "no sleep pinctrl state\n"); + + dev->pins->idle_state = pinctrl_lookup_state(dev->pins->p, + PINCTRL_STATE_IDLE); + if (IS_ERR(dev->pins->idle_state)) + /* Not supplying this state is perfectly legal */ + dev_dbg(dev, "no idle pinctrl state\n"); +#endif + + return 0; + + /* + * If no pinctrl handle or default state was found for this device, + * let's explicitly free the pin container in the device, there is + * no point in keeping it around. + */ +cleanup_get: + devm_pinctrl_put(dev->pins->p); +cleanup_alloc: + devm_kfree(dev, dev->pins); + dev->pins = NULL; + + /* Return deferrals */ + if (ret == -EPROBE_DEFER) + return ret; + /* Return serious errors */ + if (ret == -EINVAL) + return ret; + /* We ignore errors like -ENOENT meaning no pinctrl state */ + + return 0; +} -- cgit v1.3.1