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 --- tools/testing/vma/main.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 tools/testing/vma/main.c (limited to 'tools/testing/vma/main.c') diff --git a/tools/testing/vma/main.c b/tools/testing/vma/main.c new file mode 100644 index 000000000..18338f5d2 --- /dev/null +++ b/tools/testing/vma/main.c @@ -0,0 +1,57 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +#include "shared.h" +/* + * Directly import the VMA implementation here. Our vma_internal.h wrapper + * provides userland-equivalent functionality for everything vma.c uses. + */ +#include "../../../mm/vma_init.c" +#include "../../../mm/vma_exec.c" +#include "../../../mm/vma.c" + +/* Tests are included directly so they can test static functions in mm/vma.c. */ +#include "tests/merge.c" +#include "tests/mmap.c" +#include "tests/vma.c" + +int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT; + +/* Helper functions which utilise static kernel functions. */ + +struct vm_area_struct *merge_existing(struct vma_merge_struct *vmg) +{ + struct vm_area_struct *vma; + + vma = vma_merge_existing_range(vmg); + if (vma) + vma_assert_attached(vma); + return vma; +} + +int attach_vma(struct mm_struct *mm, struct vm_area_struct *vma) +{ + int res; + + res = vma_link(mm, vma); + if (!res) + vma_assert_attached(vma); + return res; +} + +/* Main test running which invokes tests/ *.c runners. */ +int main(void) +{ + int num_tests = 0, num_fail = 0; + + maple_tree_init(); + vma_state_init(); + + run_merge_tests(&num_tests, &num_fail); + run_mmap_tests(&num_tests, &num_fail); + run_vma_tests(&num_tests, &num_fail); + + printf("%d tests run, %d passed, %d failed.\n", + num_tests, num_tests - num_fail, num_fail); + + return num_fail == 0 ? EXIT_SUCCESS : EXIT_FAILURE; +} -- cgit v1.3.1