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, 63 insertions, 0 deletions

diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
new file mode 100644
index 000000000..6f5798b27
--- /dev/null
+++ b/drivers/fpga/Makefile
@@ -0,0 +1,63 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the fpga framework and fpga manager drivers.
+#
+
+# Core FPGA Manager Framework
+obj-$(CONFIG_FPGA)			+= fpga-mgr.o
+
+# FPGA Manager Drivers
+obj-$(CONFIG_FPGA_MGR_ALTERA_CVP)	+= altera-cvp.o
+obj-$(CONFIG_FPGA_MGR_ALTERA_PS_SPI)	+= altera-ps-spi.o
+obj-$(CONFIG_FPGA_MGR_ICE40_SPI)	+= ice40-spi.o
+obj-$(CONFIG_FPGA_MGR_MACHXO2_SPI)	+= machxo2-spi.o
+obj-$(CONFIG_FPGA_MGR_SOCFPGA)		+= socfpga.o
+obj-$(CONFIG_FPGA_MGR_SOCFPGA_A10)	+= socfpga-a10.o
+obj-$(CONFIG_FPGA_MGR_STRATIX10_SOC)	+= stratix10-soc.o
+obj-$(CONFIG_FPGA_MGR_TS73XX)		+= ts73xx-fpga.o
+obj-$(CONFIG_FPGA_MGR_XILINX_CORE)	+= xilinx-core.o
+obj-$(CONFIG_FPGA_MGR_XILINX_SELECTMAP)	+= xilinx-selectmap.o
+obj-$(CONFIG_FPGA_MGR_XILINX_SPI)	+= xilinx-spi.o
+obj-$(CONFIG_FPGA_MGR_ZYNQ_FPGA)	+= zynq-fpga.o
+obj-$(CONFIG_FPGA_MGR_ZYNQMP_FPGA)	+= zynqmp-fpga.o
+obj-$(CONFIG_FPGA_MGR_VERSAL_FPGA)	+= versal-fpga.o
+obj-$(CONFIG_FPGA_MGR_MICROCHIP_SPI)	+= microchip-spi.o
+obj-$(CONFIG_FPGA_MGR_LATTICE_SYSCONFIG)	+= lattice-sysconfig.o
+obj-$(CONFIG_FPGA_MGR_LATTICE_SYSCONFIG_SPI)	+= lattice-sysconfig-spi.o
+obj-$(CONFIG_ALTERA_PR_IP_CORE)		+= altera-pr-ip-core.o
+obj-$(CONFIG_ALTERA_PR_IP_CORE_PLAT)	+= altera-pr-ip-core-plat.o
+obj-$(CONFIG_FPGA_MGR_EFINIX_SPI)	+= efinix-spi.o
+
+# FPGA Secure Update Drivers
+obj-$(CONFIG_FPGA_M10_BMC_SEC_UPDATE)	+= intel-m10-bmc-sec-update.o
+
+# FPGA Bridge Drivers
+obj-$(CONFIG_FPGA_BRIDGE)		+= fpga-bridge.o
+obj-$(CONFIG_SOCFPGA_FPGA_BRIDGE)	+= altera-hps2fpga.o altera-fpga2sdram.o
+obj-$(CONFIG_ALTERA_FREEZE_BRIDGE)	+= altera-freeze-bridge.o
+obj-$(CONFIG_XILINX_PR_DECOUPLER)	+= xilinx-pr-decoupler.o
+
+# High Level Interfaces
+obj-$(CONFIG_FPGA_REGION)		+= fpga-region.o
+obj-$(CONFIG_OF_FPGA_REGION)		+= of-fpga-region.o
+
+# FPGA Device Feature List Support
+obj-$(CONFIG_FPGA_DFL)			+= dfl.o
+obj-$(CONFIG_FPGA_DFL_FME)		+= dfl-fme.o
+obj-$(CONFIG_FPGA_DFL_FME_MGR)		+= dfl-fme-mgr.o
+obj-$(CONFIG_FPGA_DFL_FME_BRIDGE)	+= dfl-fme-br.o
+obj-$(CONFIG_FPGA_DFL_FME_REGION)	+= dfl-fme-region.o
+obj-$(CONFIG_FPGA_DFL_AFU)		+= dfl-afu.o
+
+dfl-fme-objs := dfl-fme-main.o dfl-fme-pr.o dfl-fme-error.o
+dfl-fme-objs += dfl-fme-perf.o
+dfl-afu-objs := dfl-afu-main.o dfl-afu-region.o dfl-afu-dma-region.o
+dfl-afu-objs += dfl-afu-error.o
+
+obj-$(CONFIG_FPGA_DFL_NIOS_INTEL_PAC_N3000)	+= dfl-n3000-nios.o
+
+# Drivers for FPGAs which implement DFL
+obj-$(CONFIG_FPGA_DFL_PCI)		+= dfl-pci.o
+
+# KUnit tests
+obj-$(CONFIG_FPGA_KUNIT_TESTS)		+= tests/