dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel()grafted

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 <sashiko-bot@kernel.org>
Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Shivank Garg <shivankg@amd.com>
Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

1 files changed, 28 insertions, 0 deletions

diff --git a/io_uring/Makefile b/io_uring/Makefile
new file mode 100644
index 000000000..c54e328d1
--- /dev/null
+++ b/io_uring/Makefile
@@ -0,0 +1,28 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for io_uring
+
+ifdef CONFIG_GCOV_PROFILE_URING
+GCOV_PROFILE := y
+endif
+
+obj-$(CONFIG_IO_URING)		+= io_uring.o opdef.o kbuf.o rsrc.o notif.o \
+					tctx.o filetable.o rw.o poll.o \
+					tw.o wait.o eventfd.o uring_cmd.o \
+					openclose.o sqpoll.o xattr.o nop.o \
+					fs.o splice.o sync.o msg_ring.o \
+					advise.o openclose.o statx.o timeout.o \
+					cancel.o waitid.o register.o \
+					truncate.o memmap.o alloc_cache.o \
+					query.o loop.o
+
+obj-$(CONFIG_IO_URING_ZCRX)	+= zcrx.o
+obj-$(CONFIG_IO_WQ)		+= io-wq.o
+obj-$(CONFIG_FUTEX)		+= futex.o
+obj-$(CONFIG_EPOLL)		+= epoll.o
+obj-$(CONFIG_NET_RX_BUSY_POLL)	+= napi.o
+obj-$(CONFIG_NET) += net.o cmd_net.o
+obj-$(CONFIG_PROC_FS) += fdinfo.o
+obj-$(CONFIG_IO_URING_MOCK_FILE) += mock_file.o
+obj-$(CONFIG_IO_URING_BPF) += bpf_filter.o
+obj-$(CONFIG_IO_URING_BPF_OPS) += bpf-ops.o