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 --- tools/testing/vma/Makefile | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) create mode 100644 tools/testing/vma/Makefile (limited to 'tools/testing/vma/Makefile') diff --git a/tools/testing/vma/Makefile b/tools/testing/vma/Makefile new file mode 100644 index 000000000..ef6cc558a --- /dev/null +++ b/tools/testing/vma/Makefile @@ -0,0 +1,21 @@ +# SPDX-License-Identifier: GPL-2.0-or-later + +.PHONY: default clean + +default: vma + +include ../shared/shared.mk + +OFILES = $(SHARED_OFILES) main.o shared.o maple-shim.o +TARGETS = vma + +# These can be varied to test different sizes. +CFLAGS += -DNUM_VMA_FLAG_BITS=64 -DNUM_MM_FLAG_BITS=64 + +main.o: main.c shared.c shared.h vma_internal.h tests/merge.c tests/mmap.c tests/vma.c ../../../mm/vma.c ../../../mm/vma_init.c ../../../mm/vma_exec.c ../../../mm/vma.h include/custom.h include/dup.h include/stubs.h + +vma: $(OFILES) + $(CC) $(CFLAGS) -o $@ $(OFILES) $(LDLIBS) + +clean: + $(RM) $(TARGETS) *.o radix-tree.c idr.c generated/map-shift.h generated/bit-length.h generated/autoconf.h -- cgit v1.3.1