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/makelst | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100755 scripts/makelst (limited to 'scripts/makelst') diff --git a/scripts/makelst b/scripts/makelst new file mode 100755 index 000000000..e432af073 --- /dev/null +++ b/scripts/makelst @@ -0,0 +1,32 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# A script to dump mixed source code & assembly +# with correct relocations from System.map +# Requires the following lines in makefile: +#%.lst: %.c +# $(CC) $(c_flags) -g -c -o $*.o $< && +# $(srctree)/scripts/makelst $*.o System.map $(OBJDUMP) > $@ +# +# Copyright (C) 2000 IBM Corporation +# Author(s): DJ Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com) +# William Stearns +# + +# awk style field access +field() { + shift $1 ; echo $1 +} + +t1=`$3 --syms $1 | grep .text | grep -m1 " F "` +if [ -n "$t1" ]; then + t2=`field 6 $t1` + if [ ! -r $2 ]; then + echo "No System.map" >&2 + else + t3=`grep $t2 $2` + t4=`field 1 $t3` + t5=`field 1 $t1` + t6=`printf "%lu" $((0x$t4 - 0x$t5))` + fi +fi +$3 -r --source --adjust-vma=${t6:-0} $1 -- cgit v1.3.1