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, 71 insertions, 0 deletions

diff --git a/net/mac80211/Makefile b/net/mac80211/Makefile
new file mode 100644
index 000000000..36f1e3e22
--- /dev/null
+++ b/net/mac80211/Makefile
@@ -0,0 +1,71 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_MAC80211) += mac80211.o
+
+# mac80211 objects
+mac80211-y := \
+	main.o status.o \
+	driver-ops.o \
+	sta_info.o \
+	wep.o \
+	aead_api.o \
+	wpa.o \
+	scan.o offchannel.o \
+	ht.o agg-tx.o agg-rx.o \
+	vht.o \
+	he.o \
+	s1g.o \
+	ibss.o \
+	iface.o \
+	link.o \
+	rate.o \
+	tkip.o \
+	aes_cmac.o \
+	aes_gmac.o \
+	fils_aead.o \
+	cfg.o \
+	ethtool.o \
+	rx.o \
+	spectmgmt.o \
+	tx.o \
+	key.o \
+	util.o parse.o \
+	wme.o \
+	chan.o ap.o \
+	trace.o mlme.o \
+	tdls.o \
+	ocb.o \
+	airtime.o \
+	eht.o uhr.o nan.o
+
+mac80211-$(CONFIG_MAC80211_LEDS) += led.o
+mac80211-$(CONFIG_MAC80211_DEBUGFS) += \
+	debugfs.o \
+	debugfs_sta.o \
+	debugfs_netdev.o \
+	debugfs_key.o
+
+mac80211-$(CONFIG_MAC80211_MESH) += \
+	mesh.o \
+	mesh_pathtbl.o \
+	mesh_plink.o \
+	mesh_hwmp.o \
+	mesh_sync.o \
+	mesh_ps.o
+
+mac80211-$(CONFIG_PM) += pm.o
+
+CFLAGS_trace.o := -I$(src)
+
+rc80211_minstrel-y := \
+	rc80211_minstrel_ht.o
+
+rc80211_minstrel-$(CONFIG_MAC80211_DEBUGFS) += \
+	rc80211_minstrel_ht_debugfs.o
+
+mac80211-$(CONFIG_MAC80211_RC_MINSTREL) += $(rc80211_minstrel-y)
+
+obj-y += tests/
+
+mac80211-y += wbrf.o
+
+ccflags-y += -DDEBUG