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/include/nolibc/assert.h | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 tools/include/nolibc/assert.h (limited to 'tools/include/nolibc/assert.h') diff --git a/tools/include/nolibc/assert.h b/tools/include/nolibc/assert.h new file mode 100644 index 000000000..84ff8ad9a --- /dev/null +++ b/tools/include/nolibc/assert.h @@ -0,0 +1,36 @@ +/* SPDX-License-Identifier: LGPL-2.1 OR MIT */ +/* + * Assert for NOLIBC + * Copyright (C) 2026 Thomas Weißschuh + */ + +/* make sure to include all global symbols */ +#include "nolibc.h" + +#ifndef _NOLIBC_ASSERT_H +#define _NOLIBC_ASSERT_H + +#include "errno.h" +#include "stdio.h" +#include "stdlib.h" + +#endif /* _NOLIBC_ASSERT_H */ + +/* NDEBUG needs to be evaluated on *each* inclusion */ +#ifdef assert +#undef assert +#endif + +#ifndef NDEBUG +#define assert(expr) \ +({ \ + if (!(expr)) { \ + fprintf(stderr, "%s: %s:%d: %s: Assertion `%s' failed.\n", \ + program_invocation_short_name, __FILE__, __LINE__, __func__, \ + #expr); \ + abort(); \ + } \ +}) +#else +#define assert(expr) ((void)0) +#endif -- cgit v1.3.1