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/zstd/common/debug.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 lib/zstd/common/debug.c (limited to 'lib/zstd/common/debug.c') diff --git a/lib/zstd/common/debug.c b/lib/zstd/common/debug.c new file mode 100644 index 000000000..8eb6aa9a3 --- /dev/null +++ b/lib/zstd/common/debug.c @@ -0,0 +1,31 @@ +// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause +/* ****************************************************************** + * debug + * Part of FSE library + * Copyright (c) Meta Platforms, Inc. and affiliates. + * + * You can contact the author at : + * - Source repository : https://github.com/Cyan4973/FiniteStateEntropy + * + * This source code is licensed under both the BSD-style license (found in the + * LICENSE file in the root directory of this source tree) and the GPLv2 (found + * in the COPYING file in the root directory of this source tree). + * You may select, at your option, one of the above-listed licenses. +****************************************************************** */ + + +/* + * This module only hosts one global variable + * which can be used to dynamically influence the verbosity of traces, + * such as DEBUGLOG and RAWLOG + */ + +#include "debug.h" + +#if (DEBUGLEVEL>=2) +/* We only use this when DEBUGLEVEL>=2, but we get -Werror=pedantic errors if a + * translation unit is empty. So remove this from Linux kernel builds, but + * otherwise just leave it in. + */ +int g_debuglevel = DEBUGLEVEL; +#endif -- cgit v1.3.1