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/mod/Makefile | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100644 scripts/mod/Makefile (limited to 'scripts/mod/Makefile') diff --git a/scripts/mod/Makefile b/scripts/mod/Makefile new file mode 100644 index 000000000..c729bc936 --- /dev/null +++ b/scripts/mod/Makefile @@ -0,0 +1,27 @@ +# SPDX-License-Identifier: GPL-2.0 +CFLAGS_REMOVE_empty.o += $(CC_FLAGS_LTO) + +hostprogs-always-y += modpost mk_elfconfig +always-y += empty.o + +modpost-objs := modpost.o file2alias.o sumversion.o symsearch.o + +devicetable-offsets-file := devicetable-offsets.h + +$(obj)/$(devicetable-offsets-file): $(obj)/devicetable-offsets.s FORCE + $(call filechk,offsets,__DEVICETABLE_OFFSETS_H__) + +targets += $(devicetable-offsets-file) devicetable-offsets.s + +# dependencies on generated files need to be listed explicitly + +$(obj)/modpost.o $(obj)/file2alias.o $(obj)/sumversion.o $(obj)/symsearch.o: $(obj)/elfconfig.h +$(obj)/file2alias.o: $(obj)/$(devicetable-offsets-file) + +quiet_cmd_elfconfig = MKELF $@ + cmd_elfconfig = $(obj)/mk_elfconfig < $< > $@ + +$(obj)/elfconfig.h: $(obj)/empty.o $(obj)/mk_elfconfig FORCE + $(call if_changed,elfconfig) + +targets += elfconfig.h -- cgit v1.3.1