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/objtool/sync-check.sh | 77 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+) create mode 100755 tools/objtool/sync-check.sh (limited to 'tools/objtool/sync-check.sh') diff --git a/tools/objtool/sync-check.sh b/tools/objtool/sync-check.sh new file mode 100755 index 000000000..e38167ca5 --- /dev/null +++ b/tools/objtool/sync-check.sh @@ -0,0 +1,77 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 + +if [ -z "$SRCARCH" ]; then + echo 'sync-check.sh: error: missing $SRCARCH environment variable' >&2 + exit 1 +fi + +FILES="include/linux/objtool_types.h" + +if [ "$SRCARCH" = "x86" ]; then +FILES="$FILES +arch/x86/include/asm/nops.h +arch/x86/include/asm/inat_types.h +arch/x86/include/asm/orc_types.h +arch/x86/include/asm/emulate_prefix.h +arch/x86/lib/x86-opcode-map.txt +arch/x86/tools/gen-insn-attr-x86.awk +include/linux/interval_tree_generic.h +include/linux/livepatch_external.h +include/linux/static_call_types.h +" + +SYNC_CHECK_FILES=' +arch/x86/include/asm/inat.h +arch/x86/include/asm/insn.h +arch/x86/lib/inat.c +arch/x86/lib/insn.c +' +fi + +check_2 () { + file1=$1 + file2=$2 + + shift + shift + + cmd="diff $* $file1 $file2 > /dev/null" + + test -f $file2 && { + eval $cmd || { + echo "Warning: Kernel ABI header at '$file1' differs from latest version at '$file2'" >&2 + echo diff -u $file1 $file2 + } + } +} + +check () { + file=$1 + + shift + + check_2 tools/$file $file $* +} + +if [ ! -d ../../kernel ] || [ ! -d ../../tools ] || [ ! -d ../objtool ]; then + exit 0 +fi + +cd ../.. + +while read -r file_entry; do + if [ -z "$file_entry" ]; then + continue + fi + + check $file_entry +done <