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/selftests/rust/Makefile | 4 +++ tools/testing/selftests/rust/config | 6 ++++ tools/testing/selftests/rust/test_probe_samples.sh | 41 ++++++++++++++++++++++ 3 files changed, 51 insertions(+) create mode 100644 tools/testing/selftests/rust/Makefile create mode 100644 tools/testing/selftests/rust/config create mode 100755 tools/testing/selftests/rust/test_probe_samples.sh (limited to 'tools/testing/selftests/rust') diff --git a/tools/testing/selftests/rust/Makefile b/tools/testing/selftests/rust/Makefile new file mode 100644 index 000000000..fce1584d3 --- /dev/null +++ b/tools/testing/selftests/rust/Makefile @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 +TEST_PROGS += test_probe_samples.sh + +include ../lib.mk diff --git a/tools/testing/selftests/rust/config b/tools/testing/selftests/rust/config new file mode 100644 index 000000000..5f942b5c8 --- /dev/null +++ b/tools/testing/selftests/rust/config @@ -0,0 +1,6 @@ +# CONFIG_GCC_PLUGINS is not set +CONFIG_RUST=y +CONFIG_SAMPLES=y +CONFIG_SAMPLES_RUST=y +CONFIG_SAMPLE_RUST_MINIMAL=m +CONFIG_SAMPLE_RUST_PRINT=m diff --git a/tools/testing/selftests/rust/test_probe_samples.sh b/tools/testing/selftests/rust/test_probe_samples.sh new file mode 100755 index 000000000..ad0397e49 --- /dev/null +++ b/tools/testing/selftests/rust/test_probe_samples.sh @@ -0,0 +1,41 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# Copyright (c) 2023 Collabora Ltd +# +# This script tests whether the rust sample modules can +# be added and removed correctly. +# +DIR="$(dirname "$(readlink -f "$0")")" + +KTAP_HELPERS="${DIR}/../kselftest/ktap_helpers.sh" +if [ -e "$KTAP_HELPERS" ]; then + source "$KTAP_HELPERS" +else + echo "$KTAP_HELPERS file not found [SKIP]" + exit 4 +fi + +rust_sample_modules=("rust_minimal" "rust_print") + +ktap_print_header + +for sample in "${rust_sample_modules[@]}"; do + if ! /sbin/modprobe -n -q "$sample"; then + ktap_skip_all "module $sample is not found in /lib/modules/$(uname -r)" + exit "$KSFT_SKIP" + fi +done + +ktap_set_plan "${#rust_sample_modules[@]}" + +for sample in "${rust_sample_modules[@]}"; do + if /sbin/modprobe -q "$sample"; then + /sbin/modprobe -q -r "$sample" + ktap_test_pass "$sample" + else + ktap_test_fail "$sample" + fi +done + +ktap_finished -- cgit v1.3.1