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/reset/tegra/Kconfig | 4 +++ drivers/reset/tegra/Makefile | 2 ++ drivers/reset/tegra/reset-bpmp.c | 75 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 81 insertions(+) create mode 100644 drivers/reset/tegra/Kconfig create mode 100644 drivers/reset/tegra/Makefile create mode 100644 drivers/reset/tegra/reset-bpmp.c (limited to 'drivers/reset/tegra') diff --git a/drivers/reset/tegra/Kconfig b/drivers/reset/tegra/Kconfig new file mode 100644 index 000000000..4a2d26d12 --- /dev/null +++ b/drivers/reset/tegra/Kconfig @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0-only +config RESET_TEGRA_BPMP + bool "Tegra BPMP Reset Driver" if COMPILE_TEST + default TEGRA_BPMP diff --git a/drivers/reset/tegra/Makefile b/drivers/reset/tegra/Makefile new file mode 100644 index 000000000..eccba896a --- /dev/null +++ b/drivers/reset/tegra/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_RESET_TEGRA_BPMP) += reset-bpmp.o diff --git a/drivers/reset/tegra/reset-bpmp.c b/drivers/reset/tegra/reset-bpmp.c new file mode 100644 index 000000000..4c5bba52b --- /dev/null +++ b/drivers/reset/tegra/reset-bpmp.c @@ -0,0 +1,75 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2016 NVIDIA Corporation + */ + +#include + +#include +#include + +static struct tegra_bpmp *to_tegra_bpmp(struct reset_controller_dev *rstc) +{ + return container_of(rstc, struct tegra_bpmp, rstc); +} + +static int tegra_bpmp_reset_common(struct reset_controller_dev *rstc, + enum mrq_reset_commands command, + unsigned int id) +{ + struct tegra_bpmp *bpmp = to_tegra_bpmp(rstc); + struct mrq_reset_request request; + struct tegra_bpmp_message msg; + int err; + + memset(&request, 0, sizeof(request)); + request.cmd = command; + request.reset_id = id; + + memset(&msg, 0, sizeof(msg)); + msg.mrq = MRQ_RESET; + msg.tx.data = &request; + msg.tx.size = sizeof(request); + + err = tegra_bpmp_transfer(bpmp, &msg); + if (err) + return err; + if (msg.rx.ret) + return -EINVAL; + + return 0; +} + +static int tegra_bpmp_reset_module(struct reset_controller_dev *rstc, + unsigned long id) +{ + return tegra_bpmp_reset_common(rstc, CMD_RESET_MODULE, id); +} + +static int tegra_bpmp_reset_assert(struct reset_controller_dev *rstc, + unsigned long id) +{ + return tegra_bpmp_reset_common(rstc, CMD_RESET_ASSERT, id); +} + +static int tegra_bpmp_reset_deassert(struct reset_controller_dev *rstc, + unsigned long id) +{ + return tegra_bpmp_reset_common(rstc, CMD_RESET_DEASSERT, id); +} + +static const struct reset_control_ops tegra_bpmp_reset_ops = { + .reset = tegra_bpmp_reset_module, + .assert = tegra_bpmp_reset_assert, + .deassert = tegra_bpmp_reset_deassert, +}; + +int tegra_bpmp_init_resets(struct tegra_bpmp *bpmp) +{ + bpmp->rstc.ops = &tegra_bpmp_reset_ops; + bpmp->rstc.owner = THIS_MODULE; + bpmp->rstc.of_node = bpmp->dev->of_node; + bpmp->rstc.nr_resets = bpmp->soc->num_resets; + + return devm_reset_controller_register(bpmp->dev, &bpmp->rstc); +} -- cgit v1.3.1