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/bootconfig/scripts/xbc.sh | 56 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 tools/bootconfig/scripts/xbc.sh (limited to 'tools/bootconfig/scripts/xbc.sh') diff --git a/tools/bootconfig/scripts/xbc.sh b/tools/bootconfig/scripts/xbc.sh new file mode 100644 index 000000000..1f0ebf50d --- /dev/null +++ b/tools/bootconfig/scripts/xbc.sh @@ -0,0 +1,56 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0-only + +# bootconfig utility functions + +XBC_TMPFILE= +XBC_BASEDIR=`dirname $0` +BOOTCONFIG=${BOOTCONFIG:=$XBC_BASEDIR/../bootconfig} +if [ ! -x "$BOOTCONFIG" ]; then + BOOTCONFIG=`which bootconfig` + if [ -z "$BOOTCONFIG" ]; then + echo "Erorr: bootconfig command is not found" 1>&2 + exit 1 + fi +fi + +xbc_cleanup() { + if [ "$XBC_TMPFILE" ]; then + rm -f "$XBC_TMPFILE" + fi +} + +xbc_init() { # bootconfig-file + xbc_cleanup + XBC_TMPFILE=`mktemp bconf-XXXX` + trap xbc_cleanup EXIT TERM + + $BOOTCONFIG -l $1 > $XBC_TMPFILE || exit 1 +} + +nr_args() { # args + echo $# +} + +xbc_get_val() { # key [maxnum] + if [ "$2" ]; then + MAXOPT="-L $2" + fi + grep "^$1 =" $XBC_TMPFILE | cut -d= -f2- | \ + sed -e 's/", /" /g' -e "s/',/' /g" | \ + xargs $MAXOPT -n 1 echo +} + +xbc_has_key() { # key + grep -q "^$1 =" $XBC_TMPFILE +} + +xbc_has_branch() { # prefix-key + grep -q "^$1" $XBC_TMPFILE +} + +xbc_subkeys() { # prefix-key depth [subkey-pattern] + __keys=`echo $1 | sed "s/\./ /g"` + __s=`nr_args $__keys` + grep "^$1$3" $XBC_TMPFILE | cut -d= -f1| cut -d. -f$((__s + 1))-$((__s + $2)) | uniq +} -- cgit v1.3.1