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authorShivank Garg <shivankg@amd.com>2026-08-22 19:22:05 +0000
committerVinod Koul <vkoul@kernel.org>2026-09-09 17:51:44 +0530
commite873c74132f0c5f1452816cd9bb26208f0bba1e1 (patch)
treecc1ce1567f5b982359331863ebd9da38741f8d2e /tools/testing/selftests/locking
downloadlinux-stable-e873c74132f0c5f1452816cd9bb26208f0bba1e1.tar.gz
linux-stable-e873c74132f0c5f1452816cd9bb26208f0bba1e1.zip
dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel()grafted
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 <sashiko-bot@kernel.org> Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com Reviewed-by: Frank Li <Frank.Li@nxp.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Shivank Garg <shivankg@amd.com> Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'tools/testing/selftests/locking')
-rw-r--r--tools/testing/selftests/locking/Makefile10
-rwxr-xr-xtools/testing/selftests/locking/ww_mutex.sh19
2 files changed, 29 insertions, 0 deletions
diff --git a/tools/testing/selftests/locking/Makefile b/tools/testing/selftests/locking/Makefile
new file mode 100644
index 000000000..6e7761ab3
--- /dev/null
+++ b/tools/testing/selftests/locking/Makefile
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for locking/ww_mutx selftests
+
+# No binaries, but make sure arg-less "make" doesn't trigger "run_tests"
+all:
+
+TEST_PROGS := ww_mutex.sh
+
+include ../lib.mk
diff --git a/tools/testing/selftests/locking/ww_mutex.sh b/tools/testing/selftests/locking/ww_mutex.sh
new file mode 100755
index 000000000..91e4ac756
--- /dev/null
+++ b/tools/testing/selftests/locking/ww_mutex.sh
@@ -0,0 +1,19 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+
+# Runs API tests for struct ww_mutex (Wait/Wound mutexes)
+if ! /sbin/modprobe -q -n test-ww_mutex; then
+ echo "ww_mutex: module test-ww_mutex is not found [SKIP]"
+ exit $ksft_skip
+fi
+
+if /sbin/modprobe -q test-ww_mutex; then
+ /sbin/modprobe -q -r test-ww_mutex
+ echo "locking/ww_mutex: ok"
+else
+ echo "locking/ww_mutex: [FAIL]"
+ exit 1
+fi