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/firewire/uapi-test.c | 90 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 drivers/firewire/uapi-test.c (limited to 'drivers/firewire/uapi-test.c') diff --git a/drivers/firewire/uapi-test.c b/drivers/firewire/uapi-test.c new file mode 100644 index 000000000..bc3f10a2e --- /dev/null +++ b/drivers/firewire/uapi-test.c @@ -0,0 +1,90 @@ +// SPDX-License-Identifier: GPL-2.0-only +// +// uapi_test.c - An application of Kunit to check layout of structures exposed to user space for +// FireWire subsystem. +// +// Copyright (c) 2023 Takashi Sakamoto + +#include +#include + +// Known issue added at v2.6.27 kernel. +static void structure_layout_event_response(struct kunit *test) +{ +#if defined(CONFIG_X86_32) + // 4 bytes alignment for aggregate type including 8 bytes storage types. + KUNIT_EXPECT_EQ(test, 20, sizeof(struct fw_cdev_event_response)); +#else + // 8 bytes alignment for aggregate type including 8 bytes storage types. + KUNIT_EXPECT_EQ(test, 24, sizeof(struct fw_cdev_event_response)); +#endif + + KUNIT_EXPECT_EQ(test, 0, offsetof(struct fw_cdev_event_response, closure)); + KUNIT_EXPECT_EQ(test, 8, offsetof(struct fw_cdev_event_response, type)); + KUNIT_EXPECT_EQ(test, 12, offsetof(struct fw_cdev_event_response, rcode)); + KUNIT_EXPECT_EQ(test, 16, offsetof(struct fw_cdev_event_response, length)); + KUNIT_EXPECT_EQ(test, 20, offsetof(struct fw_cdev_event_response, data)); +} + +// Added at v6.5. +static void structure_layout_event_request3(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, 56, sizeof(struct fw_cdev_event_request3)); + + KUNIT_EXPECT_EQ(test, 0, offsetof(struct fw_cdev_event_request3, closure)); + KUNIT_EXPECT_EQ(test, 8, offsetof(struct fw_cdev_event_request3, type)); + KUNIT_EXPECT_EQ(test, 12, offsetof(struct fw_cdev_event_request3, tcode)); + KUNIT_EXPECT_EQ(test, 16, offsetof(struct fw_cdev_event_request3, offset)); + KUNIT_EXPECT_EQ(test, 24, offsetof(struct fw_cdev_event_request3, source_node_id)); + KUNIT_EXPECT_EQ(test, 28, offsetof(struct fw_cdev_event_request3, destination_node_id)); + KUNIT_EXPECT_EQ(test, 32, offsetof(struct fw_cdev_event_request3, card)); + KUNIT_EXPECT_EQ(test, 36, offsetof(struct fw_cdev_event_request3, generation)); + KUNIT_EXPECT_EQ(test, 40, offsetof(struct fw_cdev_event_request3, handle)); + KUNIT_EXPECT_EQ(test, 44, offsetof(struct fw_cdev_event_request3, length)); + KUNIT_EXPECT_EQ(test, 48, offsetof(struct fw_cdev_event_request3, tstamp)); + KUNIT_EXPECT_EQ(test, 56, offsetof(struct fw_cdev_event_request3, data)); +} + +// Added at v6.5. +static void structure_layout_event_response2(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, 32, sizeof(struct fw_cdev_event_response2)); + + KUNIT_EXPECT_EQ(test, 0, offsetof(struct fw_cdev_event_response2, closure)); + KUNIT_EXPECT_EQ(test, 8, offsetof(struct fw_cdev_event_response2, type)); + KUNIT_EXPECT_EQ(test, 12, offsetof(struct fw_cdev_event_response2, rcode)); + KUNIT_EXPECT_EQ(test, 16, offsetof(struct fw_cdev_event_response2, length)); + KUNIT_EXPECT_EQ(test, 20, offsetof(struct fw_cdev_event_response2, request_tstamp)); + KUNIT_EXPECT_EQ(test, 24, offsetof(struct fw_cdev_event_response2, response_tstamp)); + KUNIT_EXPECT_EQ(test, 32, offsetof(struct fw_cdev_event_response2, data)); +} + +// Added at v6.5. +static void structure_layout_event_phy_packet2(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, 24, sizeof(struct fw_cdev_event_phy_packet2)); + + KUNIT_EXPECT_EQ(test, 0, offsetof(struct fw_cdev_event_phy_packet2, closure)); + KUNIT_EXPECT_EQ(test, 8, offsetof(struct fw_cdev_event_phy_packet2, type)); + KUNIT_EXPECT_EQ(test, 12, offsetof(struct fw_cdev_event_phy_packet2, rcode)); + KUNIT_EXPECT_EQ(test, 16, offsetof(struct fw_cdev_event_phy_packet2, length)); + KUNIT_EXPECT_EQ(test, 20, offsetof(struct fw_cdev_event_phy_packet2, tstamp)); + KUNIT_EXPECT_EQ(test, 24, offsetof(struct fw_cdev_event_phy_packet2, data)); +} + +static struct kunit_case structure_layout_test_cases[] = { + KUNIT_CASE(structure_layout_event_response), + KUNIT_CASE(structure_layout_event_request3), + KUNIT_CASE(structure_layout_event_response2), + KUNIT_CASE(structure_layout_event_phy_packet2), + {} +}; + +static struct kunit_suite structure_layout_test_suite = { + .name = "firewire-uapi-structure-layout", + .test_cases = structure_layout_test_cases, +}; +kunit_test_suite(structure_layout_test_suite); + +MODULE_DESCRIPTION("FireWire UAPI unit test suite"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1