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/lib/Makefile | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 arch/alpha/lib/Makefile (limited to 'arch/alpha/lib/Makefile') diff --git a/arch/alpha/lib/Makefile b/arch/alpha/lib/Makefile new file mode 100644 index 000000000..84046e730 --- /dev/null +++ b/arch/alpha/lib/Makefile @@ -0,0 +1,46 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for alpha-specific library files.. +# + +asflags-y := $(KBUILD_CFLAGS) + +# Many of these routines have implementations tuned for ev6. +# Choose them iff we're targeting ev6 specifically. +ev6-$(CONFIG_ALPHA_EV6) := ev6- + +# Several make use of the cttz instruction introduced in ev67. +ev67-$(CONFIG_ALPHA_EV67) := ev67- + +lib-y = __divqu.o __remqu.o __divlu.o __remlu.o \ + udiv-qrnnd.o \ + udelay.o \ + $(ev6-y)memset.o \ + $(ev6-y)memcpy.o \ + memmove.o \ + checksum.o \ + csum_partial_copy.o \ + $(ev67-y)strlen.o \ + stycpy.o \ + styncpy.o \ + $(ev67-y)strchr.o \ + $(ev67-y)strrchr.o \ + $(ev6-y)memchr.o \ + $(ev6-y)copy_user.o \ + $(ev6-y)clear_user.o \ + $(ev6-y)csum_ipv6_magic.o \ + $(ev6-y)clear_page.o \ + $(ev6-y)copy_page.o \ + fpreg.o \ + callback_srm.o srm_puts.o srm_printk.o \ + fls.o + +# The division routines are built from single source, with different defines. +AFLAGS___divqu.o = -DDIV +AFLAGS___remqu.o = -DREM +AFLAGS___divlu.o = -DDIV -DINTSIZE +AFLAGS___remlu.o = -DREM -DINTSIZE + +$(addprefix $(obj)/,__divqu.o __remqu.o __divlu.o __remlu.o): \ + $(src)/$(ev6-y)divide.S FORCE + $(call if_changed_rule,as_o_S) -- cgit v1.3.1