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>

3 files changed, 89 insertions, 0 deletions

diff --git a/include/soc/imx/cpu.h b/include/soc/imx/cpu.h
new file mode 100644
index 000000000..0bf610aca
--- /dev/null
+++ b/include/soc/imx/cpu.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __IMX_CPU_H__
+#define __IMX_CPU_H__
+
+#define MXC_CPU_MX1		1
+#define MXC_CPU_MX21		21
+#define MXC_CPU_MX25		25
+#define MXC_CPU_MX27		27
+#define MXC_CPU_MX31		31
+#define MXC_CPU_MX35		35
+#define MXC_CPU_MX50		50
+#define MXC_CPU_MX51		51
+#define MXC_CPU_MX53		53
+#define MXC_CPU_IMX6SL		0x60
+#define MXC_CPU_IMX6DL		0x61
+#define MXC_CPU_IMX6SX		0x62
+#define MXC_CPU_IMX6Q		0x63
+#define MXC_CPU_IMX6UL		0x64
+#define MXC_CPU_IMX6ULL		0x65
+/* virtual cpu id for i.mx6ulz */
+#define MXC_CPU_IMX6ULZ		0x6b
+#define MXC_CPU_IMX6SLL		0x67
+#define MXC_CPU_IMX7D		0x72
+#define MXC_CPU_IMX7ULP		0xff
+
+#define MXC_CPU_VFx10		0x010
+#define MXC_CPU_VF500		0x500
+#define MXC_CPU_VF510		(MXC_CPU_VF500 | MXC_CPU_VFx10)
+#define MXC_CPU_VF600		0x600
+#define MXC_CPU_VF610		(MXC_CPU_VF600 | MXC_CPU_VFx10)
+
+#ifndef __ASSEMBLY__
+extern unsigned int __mxc_cpu_type;
+#endif
+
+#endif
diff --git a/include/soc/imx/cpuidle.h b/include/soc/imx/cpuidle.h
new file mode 100644
index 000000000..7d9202801
--- /dev/null
+++ b/include/soc/imx/cpuidle.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2016 Pengutronix, <kernel@pengutronix.de>
+ */
+
+#ifndef __SOC_IMX_CPUIDLE_H__
+#define __SOC_IMX_CPUIDLE_H__
+
+#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_SOC_IMX6Q)
+void imx6q_cpuidle_fec_irqs_used(void);
+void imx6q_cpuidle_fec_irqs_unused(void);
+#else
+static inline void imx6q_cpuidle_fec_irqs_used(void) { }
+static inline void imx6q_cpuidle_fec_irqs_unused(void) { }
+#endif
+
+#endif /* __SOC_IMX_CPUIDLE_H__ */
diff --git a/include/soc/imx/revision.h b/include/soc/imx/revision.h
new file mode 100644
index 000000000..b122d2fc8
--- /dev/null
+++ b/include/soc/imx/revision.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2015 Linaro Ltd.
+ */
+
+#ifndef __SOC_IMX_REVISION_H__
+#define __SOC_IMX_REVISION_H__
+
+#define IMX_CHIP_REVISION_1_0		0x10
+#define IMX_CHIP_REVISION_1_1		0x11
+#define IMX_CHIP_REVISION_1_2		0x12
+#define IMX_CHIP_REVISION_1_3		0x13
+#define IMX_CHIP_REVISION_1_4		0x14
+#define IMX_CHIP_REVISION_1_5		0x15
+#define IMX_CHIP_REVISION_2_0		0x20
+#define IMX_CHIP_REVISION_2_1		0x21
+#define IMX_CHIP_REVISION_2_2		0x22
+#define IMX_CHIP_REVISION_2_3		0x23
+#define IMX_CHIP_REVISION_3_0		0x30
+#define IMX_CHIP_REVISION_3_1		0x31
+#define IMX_CHIP_REVISION_3_2		0x32
+#define IMX_CHIP_REVISION_3_3		0x33
+#define IMX_CHIP_REVISION_UNKNOWN	0xff
+
+int mx25_revision(void);
+int mx27_revision(void);
+int mx31_revision(void);
+int mx35_revision(void);
+int mx51_revision(void);
+int mx53_revision(void);
+
+unsigned int imx_get_soc_revision(void);
+void imx_print_silicon_rev(const char *cpu, int srev);
+
+#endif /* __SOC_IMX_REVISION_H__ */