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 --- scripts/checkdeclares.pl | 53 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100755 scripts/checkdeclares.pl (limited to 'scripts/checkdeclares.pl') diff --git a/scripts/checkdeclares.pl b/scripts/checkdeclares.pl new file mode 100755 index 000000000..f6d551c84 --- /dev/null +++ b/scripts/checkdeclares.pl @@ -0,0 +1,53 @@ +#!/usr/bin/env perl +# SPDX-License-Identifier: GPL-2.0 +# +# checkdeclares: find struct declared more than once +# +# Copyright 2021 Wan Jiabing +# Inspired by checkincludes.pl +# +# This script checks for duplicate struct declares. +# Note that this will not take into consideration macros so +# you should run this only if you know you do have real dups +# and do not have them under #ifdef's. +# You could also just review the results. + +use strict; + +sub usage { + print "Usage: checkdeclares.pl file1.h ...\n"; + print "Warns of struct declaration duplicates\n"; + exit 1; +} + +if ($#ARGV < 0) { + usage(); +} + +my $dup_counter = 0; + +foreach my $file (@ARGV) { + open(my $f, '<', $file) + or die "Cannot open $file: $!.\n"; + + my %declaredstructs = (); + + while (<$f>) { + if (m/^\s*struct\s*(\w*);$/o) { + ++$declaredstructs{$1}; + } + } + + close($f); + + foreach my $structname (keys %declaredstructs) { + if ($declaredstructs{$structname} > 1) { + print "$file: struct $structname is declared more than once.\n"; + ++$dup_counter; + } + } +} + +if ($dup_counter == 0) { + print "No duplicate struct declares found.\n"; +} -- cgit v1.3.1