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/Makefile.btf | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 scripts/Makefile.btf (limited to 'scripts/Makefile.btf') diff --git a/scripts/Makefile.btf b/scripts/Makefile.btf new file mode 100644 index 000000000..a1812985a --- /dev/null +++ b/scripts/Makefile.btf @@ -0,0 +1,32 @@ +# SPDX-License-Identifier: GPL-2.0 + +pahole-ver := $(CONFIG_PAHOLE_VERSION) +pahole-flags-y := + +JOBS := $(patsubst -j%,%,$(filter -j%,$(MAKEFLAGS))) + +ifeq ($(call test-le, $(pahole-ver), 125),y) + +pahole-flags-y += --btf_gen_floats -j$(JOBS) + +pahole-flags-$(call test-ge, $(pahole-ver), 125) += --skip_encoding_btf_inconsistent_proto --btf_gen_optimized + +else + +# Switch to using --btf_features for v1.26 and later. +pahole-flags-$(call test-ge, $(pahole-ver), 126) = -j$(JOBS) --btf_features=encode_force,var,float,enum64,decl_tag,type_tag,optimized_func,consistent_func + +pahole-flags-$(call test-ge, $(pahole-ver), 131) += --btf_features=layout + +endif + +pahole-flags-$(CONFIG_PAHOLE_HAS_LANG_EXCLUDE) += --lang_exclude=rust + +export PAHOLE_FLAGS := $(pahole-flags-y) + +resolve-btfids-flags-y := +resolve-btfids-flags-$(CONFIG_WERROR) += --fatal_warnings +resolve-btfids-flags-$(if $(KBUILD_EXTMOD),y) += --distill_base +resolve-btfids-flags-$(if $(KBUILD_VERBOSE),y) += --verbose + +export RESOLVE_BTFIDS_FLAGS := $(resolve-btfids-flags-y) -- cgit v1.3.1