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, 90 insertions, 0 deletions

diff --git a/drivers/input/tablet/Kconfig b/drivers/input/tablet/Kconfig
new file mode 100644
index 000000000..ec27eff6a
--- /dev/null
+++ b/drivers/input/tablet/Kconfig
@@ -0,0 +1,90 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Tablet driver configuration
+#
+menuconfig INPUT_TABLET
+	bool "Tablets"
+	help
+	  Say Y here, and a list of supported tablets will be displayed.
+	  This option doesn't affect the kernel.
+
+	  If unsure, say Y.
+
+if INPUT_TABLET
+
+config TABLET_USB_ACECAD
+	tristate "Acecad Flair tablet support (USB)"
+	depends on USB_ARCH_HAS_HCD
+	select USB
+	help
+	  Say Y here if you want to use the USB version of the Acecad Flair
+	  tablet.  Make sure to say Y to "Mouse support"
+	  (CONFIG_INPUT_MOUSEDEV) and/or "Event interface support"
+	  (CONFIG_INPUT_EVDEV) as well.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called acecad.
+
+config TABLET_USB_AIPTEK
+	tristate "Aiptek 6000U/8000U and Genius G_PEN tablet support (USB)"
+	depends on USB_ARCH_HAS_HCD
+	select USB
+	help
+	  Say Y here if you want to use the USB version of the Aiptek 6000U,
+	  Aiptek 8000U or Genius G-PEN 560 tablet.  Make sure to say Y to
+	  "Mouse support" (CONFIG_INPUT_MOUSEDEV) and/or "Event interface
+	  support" (CONFIG_INPUT_EVDEV) as well.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called aiptek.
+
+config TABLET_USB_HANWANG
+	tristate "Hanwang Art Master III tablet support (USB)"
+	depends on USB_ARCH_HAS_HCD
+	select USB
+	help
+	  Say Y here if you want to use the USB version of the Hanwang Art
+	  Master III tablet.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called hanwang.
+
+config TABLET_USB_KBTAB
+	tristate "KB Gear JamStudio tablet support (USB)"
+	depends on USB_ARCH_HAS_HCD
+	select USB
+	help
+	  Say Y here if you want to use the USB version of the KB Gear
+	  JamStudio tablet.  Make sure to say Y to "Mouse support"
+	  (CONFIG_INPUT_MOUSEDEV) and/or "Event interface support"
+	  (CONFIG_INPUT_EVDEV) as well.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called kbtab.
+
+config TABLET_USB_PEGASUS
+	tristate "Pegasus Mobile Notetaker Pen input tablet support"
+	depends on USB_ARCH_HAS_HCD
+	select USB
+	help
+	  Say Y here if you want to use the Pegasus Mobile Notetaker,
+	  also known as:
+	  Genie e-note The Notetaker,
+	  Staedtler Digital ballpoint pen 990 01,
+	  IRISnotes Express or
+	  NEWLink Digital Note Taker.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called pegasus_notetaker.
+
+config TABLET_SERIAL_WACOM4
+	tristate "Wacom protocol 4 serial tablet support"
+	select SERIO
+	help
+	  Say Y here if you want to use Wacom protocol 4 serial tablets.
+	  E.g. serial versions of the Cintiq, Graphire or Penpartner.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called wacom_serial4.
+
+endif