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, 30 insertions, 0 deletions

diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
new file mode 100644
index 000000000..6482f2bfd
--- /dev/null
+++ b/drivers/extcon/Makefile
@@ -0,0 +1,30 @@
+# SPDX-License-Identifier: GPL-2.0
+
+# Makefile for external connector class (extcon) devices
+#
+
+obj-$(CONFIG_EXTCON)		+= extcon-core.o
+extcon-core-objs		+= extcon.o devres.o
+obj-$(CONFIG_EXTCON_ADC_JACK)	+= extcon-adc-jack.o
+obj-$(CONFIG_EXTCON_AXP288)	+= extcon-axp288.o
+obj-$(CONFIG_EXTCON_FSA9480)	+= extcon-fsa9480.o
+obj-$(CONFIG_EXTCON_GPIO)	+= extcon-gpio.o
+obj-$(CONFIG_EXTCON_INTEL_INT3496) += extcon-intel-int3496.o
+obj-$(CONFIG_EXTCON_INTEL_CHT_WC) += extcon-intel-cht-wc.o
+obj-$(CONFIG_EXTCON_INTEL_MRFLD) += extcon-intel-mrfld.o
+obj-$(CONFIG_EXTCON_LC824206XA)	+= extcon-lc824206xa.o
+obj-$(CONFIG_EXTCON_MAX14577)	+= extcon-max14577.o
+obj-$(CONFIG_EXTCON_MAX3355)	+= extcon-max3355.o
+obj-$(CONFIG_EXTCON_MAX77693)	+= extcon-max77693.o
+obj-$(CONFIG_EXTCON_MAX77843)	+= extcon-max77843.o
+obj-$(CONFIG_EXTCON_MAX8997)	+= extcon-max8997.o
+obj-$(CONFIG_EXTCON_MAX14526)	+= extcon-max14526.o
+obj-$(CONFIG_EXTCON_PALMAS)	+= extcon-palmas.o
+obj-$(CONFIG_EXTCON_PTN5150)	+= extcon-ptn5150.o
+obj-$(CONFIG_EXTCON_QCOM_SPMI_MISC) += extcon-qcom-spmi-misc.o
+obj-$(CONFIG_EXTCON_RT8973A)	+= extcon-rt8973a.o
+obj-$(CONFIG_EXTCON_SM5502)	+= extcon-sm5502.o
+obj-$(CONFIG_EXTCON_USB_GPIO)	+= extcon-usb-gpio.o
+obj-$(CONFIG_EXTCON_USBC_CROS_EC) += extcon-usbc-cros-ec.o
+obj-$(CONFIG_EXTCON_USBC_TUSB320) += extcon-usbc-tusb320.o
+obj-$(CONFIG_EXTCON_RTK_TYPE_C) += extcon-rtk-type-c.o