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, 25 insertions, 0 deletions

diff --git a/drivers/phy/mediatek/Makefile b/drivers/phy/mediatek/Makefile
new file mode 100644
index 000000000..ed0da7087
--- /dev/null
+++ b/drivers/phy/mediatek/Makefile
@@ -0,0 +1,25 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the phy drivers.
+#
+
+obj-$(CONFIG_PHY_MTK_DP)		+= phy-mtk-dp.o
+obj-$(CONFIG_PHY_MTK_PCIE)		+= phy-mtk-pcie.o
+obj-$(CONFIG_PHY_MTK_TPHY)		+= phy-mtk-tphy.o
+obj-$(CONFIG_PHY_MTK_UFS)		+= phy-mtk-ufs.o
+obj-$(CONFIG_PHY_MTK_XSPHY)		+= phy-mtk-xsphy.o
+obj-$(CONFIG_PHY_MTK_XFI_TPHY)		+= phy-mtk-xfi-tphy.o
+
+phy-mtk-hdmi-drv-y			:= phy-mtk-hdmi.o
+phy-mtk-hdmi-drv-y			+= phy-mtk-hdmi-mt2701.o
+phy-mtk-hdmi-drv-y			+= phy-mtk-hdmi-mt8173.o
+phy-mtk-hdmi-drv-y			+= phy-mtk-hdmi-mt8195.o
+obj-$(CONFIG_PHY_MTK_HDMI)		+= phy-mtk-hdmi-drv.o
+
+obj-$(CONFIG_PHY_MTK_MIPI_CSI_0_5)	+= phy-mtk-mipi-csi-0-5.o
+
+phy-mtk-mipi-dsi-drv-y			:= phy-mtk-mipi-dsi.o
+phy-mtk-mipi-dsi-drv-y			+= phy-mtk-mipi-dsi-mt8173.o
+phy-mtk-mipi-dsi-drv-y			+= phy-mtk-mipi-dsi-mt8183.o
+phy-mtk-mipi-dsi-drv-y			+= phy-mtk-mipi-dsi-mt8196.o
+obj-$(CONFIG_PHY_MTK_MIPI_DSI)		+= phy-mtk-mipi-dsi-drv.o