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 --- lib/kunit/hooks-impl.h | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 lib/kunit/hooks-impl.h (limited to 'lib/kunit/hooks-impl.h') diff --git a/lib/kunit/hooks-impl.h b/lib/kunit/hooks-impl.h new file mode 100644 index 000000000..d8720f261 --- /dev/null +++ b/lib/kunit/hooks-impl.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Declarations for hook implementations. + * + * These will be set as the function pointers in struct kunit_hook_table, + * found in include/kunit/test-bug.h. + * + * Copyright (C) 2023, Google LLC. + * Author: David Gow + */ + +#ifndef _KUNIT_HOOKS_IMPL_H +#define _KUNIT_HOOKS_IMPL_H + +#include + +/* List of declarations. */ +void __printf(3, 4) __kunit_fail_current_test_impl(const char *file, + int line, + const char *fmt, ...); +void *__kunit_get_static_stub_address_impl(struct kunit *test, void *real_fn_addr); +bool __kunit_is_suppressed_warning_impl(bool count); + +/* Code to set all of the function pointers. */ +static inline void kunit_install_hooks(void) +{ + /* Install the KUnit hook functions. */ + kunit_hooks.fail_current_test = __kunit_fail_current_test_impl; + kunit_hooks.get_static_stub_address = __kunit_get_static_stub_address_impl; + kunit_hooks.is_suppressed_warning = __kunit_is_suppressed_warning_impl; +} + +#endif /* _KUNIT_HOOKS_IMPL_H */ -- cgit v1.3.1