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/modules-check.sh | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100755 scripts/modules-check.sh (limited to 'scripts/modules-check.sh') diff --git a/scripts/modules-check.sh b/scripts/modules-check.sh new file mode 100755 index 000000000..4c8da90de --- /dev/null +++ b/scripts/modules-check.sh @@ -0,0 +1,26 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 + +set -e + +if [ $# != 1 ]; then + echo "Usage: $0 " >& 2 + exit 1 +fi + +exit_code=0 + +# Check uniqueness of module names +check_same_name_modules() +{ + for m in $(sed 's:.*/::' "$1" | sort | uniq -d) + do + echo "error: the following would cause module name conflict:" >&2 + sed -n "/\/$m/s:^\(.*\)\.o\$: \1.ko:p" "$1" >&2 + exit_code=1 + done +} + +check_same_name_modules "$1" + +exit $exit_code -- cgit v1.3.1