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>

6 files changed, 181 insertions, 0 deletions

diff --git a/Documentation/features/vm/ELF-ASLR/arch-support.txt b/Documentation/features/vm/ELF-ASLR/arch-support.txt
new file mode 100644
index 000000000..57406c0d5
--- /dev/null
+++ b/Documentation/features/vm/ELF-ASLR/arch-support.txt
@@ -0,0 +1,31 @@
+#
+# Feature name:          ELF-ASLR
+#         Kconfig:       ARCH_HAS_ELF_RANDOMIZE
+#         Kconfig:       ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
+#         description:   arch randomizes the stack, heap and binary images of ELF binaries
+#
+    -----------------------
+    |         arch |status|
+    -----------------------
+    |       alpha: | TODO |
+    |         arc: | TODO |
+    |         arm: |  ok  |
+    |       arm64: |  ok  |
+    |        csky: |  ok  |
+    |     hexagon: | TODO |
+    |   loongarch: |  ok  |
+    |        m68k: | TODO |
+    |  microblaze: | TODO |
+    |        mips: |  ok  |
+    |       nios2: | TODO |
+    |    openrisc: | TODO |
+    |      parisc: |  ok  |
+    |     powerpc: |  ok  |
+    |       riscv: |  ok  |
+    |        s390: |  ok  |
+    |          sh: | TODO |
+    |       sparc: | TODO |
+    |          um: | TODO |
+    |         x86: |  ok  |
+    |      xtensa: | TODO |
+    -----------------------
diff --git a/Documentation/features/vm/THP/arch-support.txt b/Documentation/features/vm/THP/arch-support.txt
new file mode 100644
index 000000000..b4a5ce169
--- /dev/null
+++ b/Documentation/features/vm/THP/arch-support.txt
@@ -0,0 +1,30 @@
+#
+# Feature name:          THP
+#         Kconfig:       HAVE_ARCH_TRANSPARENT_HUGEPAGE
+#         description:   arch supports transparent hugepages
+#
+    -----------------------
+    |         arch |status|
+    -----------------------
+    |       alpha: | TODO |
+    |         arc: |  ok  |
+    |         arm: |  ok  |
+    |       arm64: |  ok  |
+    |        csky: |  ..  |
+    |     hexagon: |  ..  |
+    |   loongarch: |  ok  |
+    |        m68k: |  ..  |
+    |  microblaze: |  ..  |
+    |        mips: |  ok  |
+    |       nios2: |  ..  |
+    |    openrisc: |  ..  |
+    |      parisc: | TODO |
+    |     powerpc: |  ok  |
+    |       riscv: |  ok  |
+    |        s390: |  ok  |
+    |          sh: |  ..  |
+    |       sparc: |  ok  |
+    |          um: |  ..  |
+    |         x86: |  ok  |
+    |      xtensa: |  ..  |
+    -----------------------
diff --git a/Documentation/features/vm/TLB/arch-support.txt b/Documentation/features/vm/TLB/arch-support.txt
new file mode 100644
index 000000000..d222bd3ee
--- /dev/null
+++ b/Documentation/features/vm/TLB/arch-support.txt
@@ -0,0 +1,30 @@
+#
+# Feature name:          batch-unmap-tlb-flush
+#         Kconfig:       ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
+#         description:   arch supports deferral of TLB flush until multiple pages are unmapped
+#
+    -----------------------
+    |         arch |status|
+    -----------------------
+    |       alpha: | TODO |
+    |         arc: | TODO |
+    |         arm: | TODO |
+    |       arm64: |  ok  |
+    |        csky: | TODO |
+    |     hexagon: | TODO |
+    |   loongarch: | TODO |
+    |        m68k: |  ..  |
+    |  microblaze: |  ..  |
+    |        mips: | TODO |
+    |       nios2: |  ..  |
+    |    openrisc: |  ..  |
+    |      parisc: | TODO |
+    |     powerpc: | TODO |
+    |       riscv: |  ok  |
+    |        s390: | TODO |
+    |          sh: | TODO |
+    |       sparc: | TODO |
+    |          um: |  ..  |
+    |         x86: |  ok  |
+    |      xtensa: | TODO |
+    -----------------------
diff --git a/Documentation/features/vm/huge-vmap/arch-support.txt b/Documentation/features/vm/huge-vmap/arch-support.txt
new file mode 100644
index 000000000..2d6de7b04
--- /dev/null
+++ b/Documentation/features/vm/huge-vmap/arch-support.txt
@@ -0,0 +1,30 @@
+#
+# Feature name:          huge-vmap
+#         Kconfig:       HAVE_ARCH_HUGE_VMAP
+#         description:   arch supports the arch_vmap_pud_supported() and arch_vmap_pmd_supported() VM APIs
+#
+    -----------------------
+    |         arch |status|
+    -----------------------
+    |       alpha: | TODO |
+    |         arc: | TODO |
+    |         arm: | TODO |
+    |       arm64: |  ok  |
+    |        csky: | TODO |
+    |     hexagon: | TODO |
+    |   loongarch: | TODO |
+    |        m68k: | TODO |
+    |  microblaze: | TODO |
+    |        mips: | TODO |
+    |       nios2: | TODO |
+    |    openrisc: | TODO |
+    |      parisc: | TODO |
+    |     powerpc: |  ok  |
+    |       riscv: |  ok  |
+    |        s390: | TODO |
+    |          sh: | TODO |
+    |       sparc: | TODO |
+    |          um: | TODO |
+    |         x86: |  ok  |
+    |      xtensa: | TODO |
+    -----------------------
diff --git a/Documentation/features/vm/ioremap_prot/arch-support.txt b/Documentation/features/vm/ioremap_prot/arch-support.txt
new file mode 100644
index 000000000..c0a2d8f56
--- /dev/null
+++ b/Documentation/features/vm/ioremap_prot/arch-support.txt
@@ -0,0 +1,30 @@
+#
+# Feature name:          ioremap_prot
+#         Kconfig:       HAVE_IOREMAP_PROT
+#         description:   arch has ioremap_prot()
+#
+    -----------------------
+    |         arch |status|
+    -----------------------
+    |       alpha: | TODO |
+    |         arc: |  ok  |
+    |         arm: | TODO |
+    |       arm64: |  ok  |
+    |        csky: | TODO |
+    |     hexagon: | TODO |
+    |   loongarch: |  ok  |
+    |        m68k: | TODO |
+    |  microblaze: | TODO |
+    |        mips: |  ok  |
+    |       nios2: | TODO |
+    |    openrisc: | TODO |
+    |      parisc: | TODO |
+    |     powerpc: |  ok  |
+    |       riscv: |  ok  |
+    |        s390: |  ok  |
+    |          sh: |  ok  |
+    |       sparc: | TODO |
+    |          um: | TODO |
+    |         x86: |  ok  |
+    |      xtensa: | TODO |
+    -----------------------
diff --git a/Documentation/features/vm/pte_special/arch-support.txt b/Documentation/features/vm/pte_special/arch-support.txt
new file mode 100644
index 000000000..3f777f8b6
--- /dev/null
+++ b/Documentation/features/vm/pte_special/arch-support.txt
@@ -0,0 +1,30 @@
+#
+# Feature name:          pte_special
+#         Kconfig:       ARCH_HAS_PTE_SPECIAL
+#         description:   arch supports the pte_special()/pte_mkspecial() VM APIs
+#
+    -----------------------
+    |         arch |status|
+    -----------------------
+    |       alpha: | TODO |
+    |         arc: |  ok  |
+    |         arm: |  ok  |
+    |       arm64: |  ok  |
+    |        csky: | TODO |
+    |     hexagon: | TODO |
+    |   loongarch: |  ok  |
+    |        m68k: | TODO |
+    |  microblaze: | TODO |
+    |        mips: |  ok  |
+    |       nios2: | TODO |
+    |    openrisc: | TODO |
+    |      parisc: |  ok  |
+    |     powerpc: |  ok  |
+    |       riscv: |  ok  |
+    |        s390: |  ok  |
+    |          sh: |  ok  |
+    |       sparc: |  ok  |
+    |          um: | TODO |
+    |         x86: |  ok  |
+    |      xtensa: | TODO |
+    -----------------------