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, 117 insertions, 0 deletions

diff --git a/drivers/phy/broadcom/Kconfig b/drivers/phy/broadcom/Kconfig
new file mode 100644
index 000000000..46371a894
--- /dev/null
+++ b/drivers/phy/broadcom/Kconfig
@@ -0,0 +1,117 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Phy drivers for Broadcom platforms
+#
+menu "PHY drivers for Broadcom platforms"
+
+config PHY_BCM63XX_USBH
+	tristate "BCM63xx USBH PHY driver"
+	depends on BMIPS_GENERIC || COMPILE_TEST
+	select GENERIC_PHY
+	help
+	  Enable this to support the BCM63xx USBH PHY driver.
+	  If unsure, say N.
+
+config PHY_CYGNUS_PCIE
+	tristate "Broadcom Cygnus PCIe PHY driver"
+	depends on OF && (ARCH_BCM_CYGNUS || COMPILE_TEST)
+	select GENERIC_PHY
+	default ARCH_BCM_CYGNUS
+	help
+	  Enable this to support the Broadcom Cygnus PCIe PHY.
+	  If unsure, say N.
+
+config PHY_BCM_SR_USB
+	tristate "Broadcom Stingray USB PHY driver"
+	depends on OF && (ARCH_BCM_IPROC || COMPILE_TEST)
+	select GENERIC_PHY
+	default ARCH_BCM_IPROC
+	help
+	  Enable this to support the Broadcom Stingray USB PHY
+	  driver. It supports all versions of Superspeed and
+	  Highspeed PHYs.
+	  If unsure, say N.
+
+config BCM_KONA_USB2_PHY
+	tristate "Broadcom Kona USB2 PHY Driver"
+	depends on HAS_IOMEM
+	select GENERIC_PHY
+	help
+	  Enable this to support the Broadcom Kona USB 2.0 PHY.
+
+config PHY_BCM_NS_USB2
+	tristate "Broadcom Northstar USB 2.0 PHY Driver"
+	depends on ARCH_BCM_IPROC || COMPILE_TEST
+	depends on HAS_IOMEM && OF
+	select GENERIC_PHY
+	help
+	  Enable this to support Broadcom USB 2.0 PHY connected to the USB
+	  controller on Northstar family.
+
+config PHY_BCM_NS_USB3
+	tristate "Broadcom Northstar USB 3.0 PHY Driver"
+	depends on ARCH_BCM_IPROC || COMPILE_TEST
+	depends on HAS_IOMEM && OF
+	depends on PHYLIB
+	select GENERIC_PHY
+	help
+	  Enable this to support Broadcom USB 3.0 PHY connected to the USB
+	  controller on Northstar family.
+
+config PHY_NS2_PCIE
+	tristate "Broadcom Northstar2 PCIe PHY driver"
+	depends on (OF && MDIO_BUS_MUX_BCM_IPROC) || (COMPILE_TEST && PHYLIB)
+	select GENERIC_PHY
+	default ARCH_BCM_IPROC
+	help
+	  Enable this to support the Broadcom Northstar2 PCIe PHY.
+	  If unsure, say N.
+
+config PHY_NS2_USB_DRD
+	tristate "Broadcom Northstar2 USB DRD PHY support"
+	depends on OF && (ARCH_BCM_IPROC || COMPILE_TEST)
+	select GENERIC_PHY
+	select EXTCON
+	default ARCH_BCM_IPROC
+	help
+	  Enable this to support the Broadcom Northstar2 USB DRD PHY.
+	  This driver initializes the PHY in either HOST or DEVICE mode.
+	  The host or device configuration is read from device tree.
+
+	  If unsure, say N.
+
+config PHY_BRCM_SATA
+	tristate "Broadcom SATA PHY driver"
+	depends on ARCH_BRCMSTB || ARCH_BCM_IPROC || BMIPS_GENERIC || \
+		   ARCH_BCMBCA || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+	default ARCH_BCM_IPROC
+	help
+	  Enable this to support the Broadcom SATA PHY.
+	  If unsure, say N.
+
+config PHY_BRCM_USB
+	tristate "Broadcom STB USB PHY driver"
+	depends on ARCH_BCMBCA || ARCH_BRCMSTB || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+	select SOC_BRCMSTB if ARCH_BRCMSTB
+	default ARCH_BCMBCA || ARCH_BRCMSTB
+	help
+	  Enable this to support the Broadcom STB USB PHY.
+	  This driver is required by the USB XHCI, EHCI and OHCI
+	  drivers.
+	  If unsure, say N.
+
+config PHY_BCM_SR_PCIE
+	tristate "Broadcom Stingray PCIe PHY driver"
+	depends on OF && (ARCH_BCM_IPROC || COMPILE_TEST)
+	select GENERIC_PHY
+	select MFD_SYSCON
+	default ARCH_BCM_IPROC
+	help
+	  Enable this to support the Broadcom Stingray PCIe PHY
+	  If unsure, say N.
+
+endmenu