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, 37 insertions, 0 deletions

diff --git a/drivers/net/mdio/Makefile b/drivers/net/mdio/Makefile
new file mode 100644
index 000000000..048586746
--- /dev/null
+++ b/drivers/net/mdio/Makefile
@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: GPL-2.0
+# Makefile for Linux MDIO bus drivers
+
+obj-$(CONFIG_ACPI_MDIO)		+= acpi_mdio.o
+obj-$(CONFIG_FWNODE_MDIO)	+= fwnode_mdio.o
+obj-$(CONFIG_OF_MDIO)		+= of_mdio.o
+
+obj-$(CONFIG_MDIO_AIROHA)		+= mdio-airoha.o
+obj-$(CONFIG_MDIO_ASPEED)		+= mdio-aspeed.o
+obj-$(CONFIG_MDIO_BCM_IPROC)		+= mdio-bcm-iproc.o
+obj-$(CONFIG_MDIO_BCM_UNIMAC)		+= mdio-bcm-unimac.o
+obj-$(CONFIG_MDIO_BITBANG)		+= mdio-bitbang.o
+obj-$(CONFIG_MDIO_CAVIUM)		+= mdio-cavium.o
+obj-$(CONFIG_MDIO_GPIO)			+= mdio-gpio.o
+obj-$(CONFIG_MDIO_HISI_FEMAC)		+= mdio-hisi-femac.o
+obj-$(CONFIG_MDIO_I2C)			+= mdio-i2c.o
+obj-$(CONFIG_MDIO_IPQ4019)		+= mdio-ipq4019.o
+obj-$(CONFIG_MDIO_IPQ8064)		+= mdio-ipq8064.o
+obj-$(CONFIG_MDIO_MOXART)		+= mdio-moxart.o
+obj-$(CONFIG_MDIO_MSCC_MIIM)		+= mdio-mscc-miim.o
+obj-$(CONFIG_MDIO_MVUSB)		+= mdio-mvusb.o
+obj-$(CONFIG_MDIO_OCTEON)		+= mdio-octeon.o
+obj-$(CONFIG_MDIO_PIC64HPSC)		+= mdio-pic64hpsc.o
+obj-$(CONFIG_MDIO_REALTEK_RTL9300)	+= mdio-realtek-rtl9300.o
+obj-$(CONFIG_MDIO_REGMAP)		+= mdio-regmap.o
+obj-$(CONFIG_MDIO_SUN4I)		+= mdio-sun4i.o
+obj-$(CONFIG_MDIO_THUNDER)		+= mdio-thunder.o
+obj-$(CONFIG_MDIO_XGENE)		+= mdio-xgene.o
+
+obj-$(CONFIG_MDIO_BUS_MUX)		+= mdio-mux.o
+obj-$(CONFIG_MDIO_BUS_MUX_BCM6368)	+= mdio-mux-bcm6368.o
+obj-$(CONFIG_MDIO_BUS_MUX_BCM_IPROC)	+= mdio-mux-bcm-iproc.o
+obj-$(CONFIG_MDIO_BUS_MUX_GPIO)		+= mdio-mux-gpio.o
+obj-$(CONFIG_MDIO_BUS_MUX_MESON_G12A)	+= mdio-mux-meson-g12a.o
+obj-$(CONFIG_MDIO_BUS_MUX_MESON_GXL)	+= mdio-mux-meson-gxl.o
+obj-$(CONFIG_MDIO_BUS_MUX_MMIOREG) 	+= mdio-mux-mmioreg.o
+obj-$(CONFIG_MDIO_BUS_MUX_MULTIPLEXER) 	+= mdio-mux-multiplexer.o