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 --- lib/vdso/Makefile.include | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) create mode 100644 lib/vdso/Makefile.include (limited to 'lib/vdso/Makefile.include') diff --git a/lib/vdso/Makefile.include b/lib/vdso/Makefile.include new file mode 100644 index 000000000..cedbf15f8 --- /dev/null +++ b/lib/vdso/Makefile.include @@ -0,0 +1,18 @@ +# SPDX-License-Identifier: GPL-2.0 + +GENERIC_VDSO_MK_PATH := $(abspath $(lastword $(MAKEFILE_LIST))) +GENERIC_VDSO_DIR := $(dir $(GENERIC_VDSO_MK_PATH)) + +c-gettimeofday-$(CONFIG_GENERIC_GETTIMEOFDAY) := $(addprefix $(GENERIC_VDSO_DIR), gettimeofday.c) +c-getrandom-$(CONFIG_VDSO_GETRANDOM) := $(addprefix $(GENERIC_VDSO_DIR), getrandom.c) + +# This cmd checks that the vdso library does not contain dynamic relocations. +# It has to be called after the linking of the vdso library and requires it +# as a parameter. +# +# As a workaround for some GNU ld ports which produce unneeded R_*_NONE +# dynamic relocations, ignore R_*_NONE. +quiet_cmd_vdso_check = VDSOCHK $@ + cmd_vdso_check = if $(READELF) -rW $@ | grep -v _NONE | grep -q " R_\w*_"; \ + then (echo >&2 "$@: dynamic relocations are not supported"; \ + rm -f $@; /bin/false); fi -- cgit v1.3.1