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/check-function-names.sh | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100755 scripts/check-function-names.sh (limited to 'scripts/check-function-names.sh') diff --git a/scripts/check-function-names.sh b/scripts/check-function-names.sh new file mode 100755 index 000000000..08071133e --- /dev/null +++ b/scripts/check-function-names.sh @@ -0,0 +1,25 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# +# Certain function names are disallowed due to section name ambiguities +# introduced by -ffunction-sections. +# +# See the comment above TEXT_MAIN in include/asm-generic/vmlinux.lds.h. + +objfile="$1" + +if [ ! -f "$objfile" ]; then + echo "usage: $0 " >&2 + exit 1 +fi + +bad_symbols=$(${NM:-nm} "$objfile" | awk '$2 ~ /^[TtWw]$/ {print $3}' | grep -E '^(startup|exit|split|unlikely|hot|unknown)(\.|$)') + +if [ -n "$bad_symbols" ]; then + echo "$bad_symbols" | while read -r sym; do + echo "$objfile: error: $sym() function name creates ambiguity with -ffunction-sections" >&2 + done + exit 1 +fi + +exit 0 -- cgit v1.3.1