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/nvdimm/dax-dev.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) create mode 100644 tools/testing/nvdimm/dax-dev.c (limited to 'tools/testing/nvdimm/dax-dev.c') diff --git a/tools/testing/nvdimm/dax-dev.c b/tools/testing/nvdimm/dax-dev.c new file mode 100644 index 000000000..fb342a8c9 --- /dev/null +++ b/tools/testing/nvdimm/dax-dev.c @@ -0,0 +1,39 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2016, Intel Corporation. + */ +#include "test/nfit_test.h" +#include +#include "../../../drivers/dax/dax-private.h" + +phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff, + unsigned long size) +{ + int i; + + for (i = 0; i < dev_dax->nr_range; i++) { + struct dev_dax_range *dax_range = &dev_dax->ranges[i]; + struct range *range = &dax_range->range; + unsigned long long pgoff_end; + phys_addr_t addr; + + pgoff_end = dax_range->pgoff + PHYS_PFN(range_len(range)) - 1; + if (pgoff < dax_range->pgoff || pgoff > pgoff_end) + continue; + addr = PFN_PHYS(pgoff - dax_range->pgoff) + range->start; + if (addr + size - 1 <= range->end) { + if (get_nfit_res(addr)) { + struct page *page; + + if (dev_dax->region->align > PAGE_SIZE) + return -1; + + page = vmalloc_to_page((void *)addr); + return PFN_PHYS(page_to_pfn(page)); + } + return addr; + } + break; + } + return -1; +} -- cgit v1.3.1