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/stackusage | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) create mode 100755 scripts/stackusage (limited to 'scripts/stackusage') diff --git a/scripts/stackusage b/scripts/stackusage new file mode 100755 index 000000000..56ef1ab67 --- /dev/null +++ b/scripts/stackusage @@ -0,0 +1,34 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 + +outfile="" +now=`date +%s` + +while [ $# -gt 0 ] +do + case "$1" in + -o) + outfile="$2" + shift 2;; + -h) + echo "usage: $0 [-o outfile] " + exit 0;; + *) break;; + esac +done + +if [ -z "$outfile" ] +then + outfile=`mktemp --tmpdir stackusage.$$.XXXX` +fi + +KCFLAGS="${KCFLAGS} -fstack-usage" make "$@" + +# Prepend directory name to file names, remove column information, +# make file:line/function/size/type properly tab-separated. +find . -name '*.su' -newermt "@${now}" -print | \ + xargs perl -MFile::Basename -pe \ + '$d = dirname($ARGV); s#([^:]+:[0-9]+):[0-9]+:#$d/$1\t#;' | \ + sort -k3,3nr > "${outfile}" + +echo "$0: output written to ${outfile}" -- cgit v1.3.1