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, 32 insertions, 0 deletions

diff --git a/drivers/crypto/caam/Makefile b/drivers/crypto/caam/Makefile
new file mode 100644
index 000000000..a17e3cf14
--- /dev/null
+++ b/drivers/crypto/caam/Makefile
@@ -0,0 +1,32 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the CAAM backend and dependent components
+#
+ifeq ($(CONFIG_CRYPTO_DEV_FSL_CAAM_DEBUG), y)
+	ccflags-y := -DDEBUG
+endif
+
+ccflags-y += -DVERSION=\"\"
+
+obj-$(CONFIG_CRYPTO_DEV_FSL_CAAM_COMMON) += error.o
+obj-$(CONFIG_CRYPTO_DEV_FSL_CAAM) += caam.o
+obj-$(CONFIG_CRYPTO_DEV_FSL_CAAM_JR) += caam_jr.o
+obj-$(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_DESC) += caamalg_desc.o
+obj-$(CONFIG_CRYPTO_DEV_FSL_CAAM_AHASH_API_DESC) += caamhash_desc.o
+
+caam-y := ctrl.o
+caam_jr-y := jr.o key_gen.o
+caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API) += caamalg.o
+caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI) += caamalg_qi.o
+caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_AHASH_API) += caamhash.o
+caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_RNG_API) += caamrng.o
+caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_PKC_API) += caampkc.o pkc_desc.o
+caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_BLOB_GEN) += blob_gen.o
+
+caam-$(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI) += qi.o
+caam-$(CONFIG_DEBUG_FS) += debugfs.o
+
+obj-$(CONFIG_CRYPTO_DEV_FSL_DPAA2_CAAM) += dpaa2_caam.o
+
+dpaa2_caam-y    := caamalg_qi2.o dpseci.o
+dpaa2_caam-$(CONFIG_DEBUG_FS) += dpseci-debugfs.o