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, 60 insertions, 0 deletions

diff --git a/drivers/accessibility/speakup/Makefile b/drivers/accessibility/speakup/Makefile
new file mode 100644
index 000000000..14ba1cca8
--- /dev/null
+++ b/drivers/accessibility/speakup/Makefile
@@ -0,0 +1,60 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_SPEAKUP_SYNTH_ACNTSA) += speakup_acntsa.o
+obj-$(CONFIG_SPEAKUP_SYNTH_ACNTPC) += speakup_acntpc.o
+obj-$(CONFIG_SPEAKUP_SYNTH_APOLLO) += speakup_apollo.o
+obj-$(CONFIG_SPEAKUP_SYNTH_AUDPTR) += speakup_audptr.o
+obj-$(CONFIG_SPEAKUP_SYNTH_BNS) += speakup_bns.o
+obj-$(CONFIG_SPEAKUP_SYNTH_DECTLK) += speakup_dectlk.o
+obj-$(CONFIG_SPEAKUP_SYNTH_DECEXT) += speakup_decext.o
+obj-$(CONFIG_SPEAKUP_SYNTH_DECPC) += speakup_decpc.o
+obj-$(CONFIG_SPEAKUP_SYNTH_DTLK) += speakup_dtlk.o
+obj-$(CONFIG_SPEAKUP_SYNTH_KEYPC) += speakup_keypc.o
+obj-$(CONFIG_SPEAKUP_SYNTH_LTLK) += speakup_ltlk.o
+obj-$(CONFIG_SPEAKUP_SYNTH_SOFT) += speakup_soft.o
+obj-$(CONFIG_SPEAKUP_SYNTH_SPKOUT) += speakup_spkout.o
+obj-$(CONFIG_SPEAKUP_SYNTH_TXPRT) += speakup_txprt.o
+obj-$(CONFIG_SPEAKUP_SYNTH_DUMMY) += speakup_dummy.o
+
+obj-$(CONFIG_SPEAKUP) += speakup.o
+speakup-y := \
+	buffers.o \
+	devsynth.o \
+	i18n.o \
+	fakekey.o \
+	main.o \
+	keyhelp.o \
+	kobjects.o \
+	selection.o \
+	spk_ttyio.o \
+	synth.o \
+	thread.o \
+	varhandlers.o
+speakup-$(CONFIG_SPEAKUP_SERIALIO) += serialio.o
+
+
+clean-files := mapdata.h speakupmap.h
+
+
+# Generate mapdata.h from headers
+hostprogs += makemapdata
+makemapdata-objs := makemapdata.o
+
+quiet_cmd_mkmap = MKMAP   $@
+      cmd_mkmap = TOPDIR=$(srctree) SPKDIR=$(src) $(obj)/makemapdata > $@
+
+$(obj)/mapdata.h: $(obj)/makemapdata
+	$(call cmd,mkmap)
+
+
+# Generate speakupmap.h from mapdata.h
+hostprogs += genmap
+genmap-objs := genmap.o
+$(obj)/genmap.o: $(obj)/mapdata.h
+
+quiet_cmd_genmap = GENMAP  $@
+      cmd_genmap = $(obj)/genmap $< > $@
+
+$(obj)/speakupmap.h: $(src)/speakupmap.map $(obj)/genmap
+	$(call cmd,genmap)
+
+$(obj)/main.o: $(obj)/speakupmap.h