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.randstruct | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) create mode 100644 scripts/Makefile.randstruct (limited to 'scripts/Makefile.randstruct') diff --git a/scripts/Makefile.randstruct b/scripts/Makefile.randstruct new file mode 100644 index 000000000..24e283e89 --- /dev/null +++ b/scripts/Makefile.randstruct @@ -0,0 +1,17 @@ +# SPDX-License-Identifier: GPL-2.0 + +randstruct-cflags-y += -DRANDSTRUCT + +ifdef CONFIG_GCC_PLUGIN_RANDSTRUCT +randstruct-cflags-y \ + += -fplugin=$(objtree)/scripts/gcc-plugins/randomize_layout_plugin.so +randstruct-cflags-$(CONFIG_RANDSTRUCT_PERFORMANCE) \ + += -fplugin-arg-randomize_layout_plugin-performance-mode +else +randstruct-cflags-y \ + += -frandomize-layout-seed-file=$(objtree)/scripts/basic/randstruct.seed +endif + +export RANDSTRUCT_CFLAGS := $(randstruct-cflags-y) + +KBUILD_CFLAGS += $(RANDSTRUCT_CFLAGS) -- cgit v1.3.1