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 --- arch/alpha/Makefile | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) create mode 100644 arch/alpha/Makefile (limited to 'arch/alpha/Makefile') diff --git a/arch/alpha/Makefile b/arch/alpha/Makefile new file mode 100644 index 000000000..7074602dc --- /dev/null +++ b/arch/alpha/Makefile @@ -0,0 +1,66 @@ +# +# alpha/Makefile +# +# This file is subject to the terms and conditions of the GNU General Public +# License. See the file "COPYING" in the main directory of this archive +# for more details. +# +# Copyright (C) 1994 by Linus Torvalds +# + +NM := $(NM) -B + +LDFLAGS_vmlinux := -static -N #-relax +CHECKFLAGS += -D__alpha__ +cflags-y := -pipe -mno-fp-regs -ffixed-8 +cflags-y += $(call cc-option, -fno-jump-tables) + +cpuflags-$(CONFIG_ALPHA_EV56) := -mcpu=ev56 +cpuflags-$(CONFIG_ALPHA_POLARIS) := -mcpu=pca56 +cpuflags-$(CONFIG_ALPHA_SX164) := -mcpu=pca56 +cpuflags-$(CONFIG_ALPHA_EV6) := -mcpu=ev6 +cpuflags-$(CONFIG_ALPHA_EV67) := -mcpu=ev67 +# If GENERIC, make sure to turn off any instruction set extensions that +# the host compiler might have on by default. +cpuflags-$(CONFIG_ALPHA_GENERIC) := -mcpu=ev56 -mtune=ev6 + +cflags-y += $(cpuflags-y) + + +KBUILD_CFLAGS += $(cflags-y) + +# For TSUNAMI, we must have the assembler not emulate our instructions. +# The same is true for IRONGATE, POLARIS, PYXIS. +# BWX is most important, but we don't really want any emulation ever. +# Only gas emulates instructions the target does not implement, and only gas +# understands -mev6. LLVM's integrated assembler never emulates. +ifdef CONFIG_AS_IS_GNU +KBUILD_CFLAGS += -Wa,-mev6 +endif + +libs-y += arch/alpha/lib/ + +# export what is needed by arch/alpha/boot/Makefile +LIBS_Y := $(patsubst %/, %/lib.a, $(libs-y)) +export LIBS_Y + +boot := arch/alpha/boot + +#Default target when executing make with no arguments +all boot: $(boot)/vmlinux.gz + +$(boot)/vmlinux.gz: vmlinux + $(Q)$(MAKE) $(build)=$(boot) $@ + +bootimage bootpfile bootpzfile: vmlinux + $(Q)$(MAKE) $(build)=$(boot) $(boot)/$@ + +archheaders: + $(Q)$(MAKE) $(build)=arch/alpha/kernel/syscalls all + +define archhelp + echo '* boot - Compressed kernel image (arch/alpha/boot/vmlinux.gz)' + echo ' bootimage - SRM bootable image (arch/alpha/boot/bootimage)' + echo ' bootpfile - BOOTP bootable image (arch/alpha/boot/bootpfile)' + echo ' bootpzfile - compressed kernel BOOTP image (arch/alpha/boot/bootpzfile)' +endef -- cgit v1.3.1