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/ktest/compare-ktest-sample.pl | 33 +++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100755 tools/testing/ktest/compare-ktest-sample.pl (limited to 'tools/testing/ktest/compare-ktest-sample.pl') diff --git a/tools/testing/ktest/compare-ktest-sample.pl b/tools/testing/ktest/compare-ktest-sample.pl new file mode 100755 index 000000000..ebea21d0a --- /dev/null +++ b/tools/testing/ktest/compare-ktest-sample.pl @@ -0,0 +1,33 @@ +#!/usr/bin/env perl +# SPDX-License-Identifier: GPL-2.0 + +open (IN,"ktest.pl"); +while () { + # hashes are now used + if (/\$opt\{"?([A-Z].*?)(\[.*\])?"?\}/ || + /^\s*"?([A-Z].*?)"?\s*=>\s*/ || + /set_test_option\("(.*?)"/) { + $opt{$1} = 1; + } +} +close IN; + +open (IN, "sample.conf"); +while () { + if (/^\s*#?\s*([A-Z]\S*)\s*=/) { + $samp{$1} = 1; + } +} +close IN; + +foreach $opt (keys %opt) { + if (!defined($samp{$opt})) { + print "opt = $opt\n"; + } +} + +foreach $samp (keys %samp) { + if (!defined($opt{$samp})) { + print "samp = $samp\n"; + } +} -- cgit v1.3.1