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>

9 files changed, 176 insertions, 0 deletions

diff --git a/tools/include/asm/alternative.h b/tools/include/asm/alternative.h
new file mode 100644
index 000000000..8e548ac8f
--- /dev/null
+++ b/tools/include/asm/alternative.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _TOOLS_ASM_ALTERNATIVE_ASM_H
+#define _TOOLS_ASM_ALTERNATIVE_ASM_H
+
+#if defined(__s390x__)
+#ifdef __ASSEMBLY__
+.macro ALTERNATIVE oldinstr, newinstr, feature
+	\oldinstr
+.endm
+#endif
+#else
+
+/* Just disable it so we can build arch/x86/lib/memcpy_64.S for perf bench: */
+
+#define ALTERNATIVE #
+
+#endif
+
+#endif
diff --git a/tools/include/asm/atomic.h b/tools/include/asm/atomic.h
new file mode 100644
index 000000000..8c9bfffd4
--- /dev/null
+++ b/tools/include/asm/atomic.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __TOOLS_LINUX_ASM_ATOMIC_H
+#define __TOOLS_LINUX_ASM_ATOMIC_H
+
+#if defined(__i386__) || defined(__x86_64__)
+#include "../../arch/x86/include/asm/atomic.h"
+#else
+#include <asm-generic/atomic-gcc.h>
+#endif
+
+#endif /* __TOOLS_LINUX_ASM_ATOMIC_H */
diff --git a/tools/include/asm/barrier.h b/tools/include/asm/barrier.h
new file mode 100644
index 000000000..0c21678ac
--- /dev/null
+++ b/tools/include/asm/barrier.h
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/compiler.h>
+#if defined(__i386__) || defined(__x86_64__)
+#include "../../arch/x86/include/asm/barrier.h"
+#elif defined(__arm__)
+#include "../../arch/arm/include/asm/barrier.h"
+#elif defined(__aarch64__)
+#include "../../arch/arm64/include/asm/barrier.h"
+#elif defined(__powerpc__)
+#include "../../arch/powerpc/include/asm/barrier.h"
+#elif defined(__riscv)
+#include "../../arch/riscv/include/asm/barrier.h"
+#elif defined(__s390__)
+#include "../../arch/s390/include/asm/barrier.h"
+#elif defined(__sh__)
+#include "../../arch/sh/include/asm/barrier.h"
+#elif defined(__sparc__)
+#include "../../arch/sparc/include/asm/barrier.h"
+#elif defined(__tile__)
+#include "../../arch/tile/include/asm/barrier.h"
+#elif defined(__alpha__)
+#include "../../arch/alpha/include/asm/barrier.h"
+#elif defined(__mips__)
+#include "../../arch/mips/include/asm/barrier.h"
+#elif defined(__ia64__)
+#include "../../arch/ia64/include/asm/barrier.h"
+#elif defined(__xtensa__)
+#include "../../arch/xtensa/include/asm/barrier.h"
+#else
+#include <asm-generic/barrier.h>
+#endif
+
+/*
+ * Generic fallback smp_*() definitions for archs that haven't
+ * been updated yet.
+ */
+
+#ifndef smp_rmb
+# define smp_rmb()	rmb()
+#endif
+
+#ifndef smp_wmb
+# define smp_wmb()	wmb()
+#endif
+
+#ifndef smp_mb
+# define smp_mb()	mb()
+#endif
+
+#ifndef smp_store_release
+# define smp_store_release(p, v)		\
+do {						\
+	smp_mb();				\
+	WRITE_ONCE(*p, v);			\
+} while (0)
+#endif
+
+#ifndef smp_load_acquire
+# define smp_load_acquire(p)			\
+({						\
+	typeof(*p) ___p1 = READ_ONCE(*p);	\
+	smp_mb();				\
+	___p1;					\
+})
+#endif
diff --git a/tools/include/asm/bug.h b/tools/include/asm/bug.h
new file mode 100644
index 000000000..550223f0a
--- /dev/null
+++ b/tools/include/asm/bug.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _TOOLS_ASM_BUG_H
+#define _TOOLS_ASM_BUG_H
+
+#include <linux/compiler.h>
+#include <stdio.h>
+
+#define __WARN_printf(arg...)	do { fprintf(stderr, arg); } while (0)
+
+#define WARN(condition, format...) ({		\
+	int __ret_warn_on = !!(condition);	\
+	if (unlikely(__ret_warn_on))		\
+		__WARN_printf(format);		\
+	unlikely(__ret_warn_on);		\
+})
+
+#define WARN_ON(condition) ({					\
+	int __ret_warn_on = !!(condition);			\
+	if (unlikely(__ret_warn_on))				\
+		__WARN_printf("assertion failed at %s:%d\n",	\
+				__FILE__, __LINE__);		\
+	unlikely(__ret_warn_on);				\
+})
+
+#define WARN_ON_ONCE(condition) ({			\
+	static int __warned;				\
+	int __ret_warn_once = !!(condition);		\
+							\
+	if (unlikely(__ret_warn_once && !__warned)) {	\
+		__warned = true;			\
+		WARN_ON(1);				\
+	}						\
+	unlikely(__ret_warn_once);			\
+})
+
+#define WARN_ONCE(condition, format...)	({	\
+	static int __warned;			\
+	int __ret_warn_once = !!(condition);	\
+						\
+	if (unlikely(__ret_warn_once))		\
+		if (WARN(!__warned, format)) 	\
+			__warned = 1;		\
+	unlikely(__ret_warn_once);		\
+})
+
+#endif /* _TOOLS_ASM_BUG_H */
diff --git a/tools/include/asm/export.h b/tools/include/asm/export.h
new file mode 100644
index 000000000..2cb1a0d83
--- /dev/null
+++ b/tools/include/asm/export.h
@@ -0,0 +1,7 @@
+#ifndef _TOOLS_ASM_EXPORT_H
+#define _TOOLS_ASM_EXPORT_H
+
+#define EXPORT_SYMBOL(x)
+#define EXPORT_SYMBOL_GPL(x)
+
+#endif /* _TOOLS_ASM_EXPORT_H */
diff --git a/tools/include/asm/io.h b/tools/include/asm/io.h
new file mode 100644
index 000000000..eed5066f2
--- /dev/null
+++ b/tools/include/asm/io.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _TOOLS_ASM_IO_H
+#define _TOOLS_ASM_IO_H
+
+#if defined(__i386__) || defined(__x86_64__)
+#include "../../arch/x86/include/asm/io.h"
+#else
+#include <asm-generic/io.h>
+#endif
+
+#endif /* _TOOLS_ASM_IO_H */
diff --git a/tools/include/asm/rwonce.h b/tools/include/asm/rwonce.h
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tools/include/asm/rwonce.h
diff --git a/tools/include/asm/sections.h b/tools/include/asm/sections.h
new file mode 100644
index 000000000..a80643d7a
--- /dev/null
+++ b/tools/include/asm/sections.h
@@ -0,0 +1,4 @@
+#ifndef __TOOLS_INCLUDE_LINUX_ASM_SECTIONS_H
+#define __TOOLS_INCLUDE_LINUX_ASM_SECTIONS_H
+
+#endif /* __TOOLS_INCLUDE_LINUX_ASM_SECTIONS_H */
diff --git a/tools/include/asm/timex.h b/tools/include/asm/timex.h
new file mode 100644
index 000000000..5adfe3c6d
--- /dev/null
+++ b/tools/include/asm/timex.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __TOOLS_LINUX_ASM_TIMEX_H
+#define __TOOLS_LINUX_ASM_TIMEX_H
+
+#include <time.h>
+
+#define cycles_t clock_t
+
+static inline cycles_t get_cycles(void)
+{
+	return clock();
+}
+#endif // __TOOLS_LINUX_ASM_TIMEX_H