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, 99 insertions, 0 deletions

diff --git a/crypto/tcrypt.h b/crypto/tcrypt.h
new file mode 100644
index 000000000..85c3f77bc
--- /dev/null
+++ b/crypto/tcrypt.h
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Quick & dirty crypto benchmarking module.
+ *
+ * This will only exist until we have a better benchmarking mechanism
+ * (e.g. a char device).
+ *
+ * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
+ * Copyright (c) 2002 Jean-Francois Dive <jef@linuxbe.org>
+ * Copyright (c) 2007 Nokia Siemens Networks
+ */
+#ifndef _CRYPTO_TCRYPT_H
+#define _CRYPTO_TCRYPT_H
+
+struct cipher_speed_template {
+	const char *key;
+	unsigned int klen;
+};
+
+struct aead_speed_template {
+	const char *key;
+	unsigned int klen;
+};
+
+struct hash_speed {
+	unsigned int blen;	/* buffer length */
+	unsigned int plen;	/* per-update length */
+};
+
+/*
+ * DES test vectors.
+ */
+#define DES3_SPEED_VECTORS	1
+
+static struct cipher_speed_template des3_speed_template[] = {
+	{
+		.key	= "\x01\x23\x45\x67\x89\xab\xcd\xef"
+			  "\x55\x55\x55\x55\x55\x55\x55\x55"
+			  "\xfe\xdc\xba\x98\x76\x54\x32\x10",
+		.klen	= 24,
+	}
+};
+
+/*
+ * Cipher speed tests
+ */
+static u8 speed_template_8[] = {8, 0};
+static u8 speed_template_16[] = {16, 0};
+static u8 speed_template_24[] = {24, 0};
+static u8 speed_template_8_16[] = {8, 16, 0};
+static u8 speed_template_8_32[] = {8, 32, 0};
+static u8 speed_template_16_32[] = {16, 32, 0};
+static u8 speed_template_16_24_32[] = {16, 24, 32, 0};
+static u8 speed_template_20_28_36[] = {20, 28, 36, 0};
+static u8 speed_template_32_40_48[] = {32, 40, 48, 0};
+static u8 speed_template_32_48[] = {32, 48, 0};
+static u8 speed_template_32_48_64[] = {32, 48, 64, 0};
+static u8 speed_template_32_64[] = {32, 64, 0};
+static u8 speed_template_32[] = {32, 0};
+
+/*
+ * AEAD speed tests
+ */
+static u8 aead_speed_template_19[] = {19, 0};
+static u8 aead_speed_template_20_28_36[] = {20, 28, 36, 0};
+static u8 aead_speed_template_36[] = {36, 0};
+
+/*
+ * Digest speed tests
+ */
+static struct hash_speed generic_hash_speed_template[] = {
+	{ .blen = 16,	.plen = 16, },
+	{ .blen = 64,	.plen = 16, },
+	{ .blen = 64,	.plen = 64, },
+	{ .blen = 256,	.plen = 16, },
+	{ .blen = 256,	.plen = 64, },
+	{ .blen = 256,	.plen = 256, },
+	{ .blen = 1024,	.plen = 16, },
+	{ .blen = 1024,	.plen = 256, },
+	{ .blen = 1024,	.plen = 1024, },
+	{ .blen = 2048,	.plen = 16, },
+	{ .blen = 2048,	.plen = 256, },
+	{ .blen = 2048,	.plen = 1024, },
+	{ .blen = 2048,	.plen = 2048, },
+	{ .blen = 4096,	.plen = 16, },
+	{ .blen = 4096,	.plen = 256, },
+	{ .blen = 4096,	.plen = 1024, },
+	{ .blen = 4096,	.plen = 4096, },
+	{ .blen = 8192,	.plen = 16, },
+	{ .blen = 8192,	.plen = 256, },
+	{ .blen = 8192,	.plen = 1024, },
+	{ .blen = 8192,	.plen = 4096, },
+	{ .blen = 8192,	.plen = 8192, },
+
+	/* End marker */
+	{  .blen = 0,	.plen = 0, }
+};
+
+#endif	/* _CRYPTO_TCRYPT_H */