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, 37 insertions, 0 deletions

diff --git a/net/bridge/Makefile b/net/bridge/Makefile
new file mode 100644
index 000000000..1203dc19e
--- /dev/null
+++ b/net/bridge/Makefile
@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the IEEE 802.1d ethernet bridging layer.
+#
+
+obj-$(CONFIG_BRIDGE) += bridge.o
+
+bridge-y	:= br.o br_device.o br_fdb.o br_forward.o br_if.o br_input.o \
+			br_ioctl.o br_stp.o br_stp_bpdu.o \
+			br_stp_if.o br_stp_timer.o br_netlink.o \
+			br_netlink_tunnel.o br_arp_nd_proxy.o
+
+bridge-$(CONFIG_SYSFS) += br_sysfs_if.o br_sysfs_br.o
+
+bridge-$(subst m,y,$(CONFIG_BRIDGE_NETFILTER)) += br_nf_core.o
+
+br_netfilter-y := br_netfilter_hooks.o
+br_netfilter-$(subst m,y,$(CONFIG_IPV6)) += br_netfilter_ipv6.o
+obj-$(CONFIG_BRIDGE_NETFILTER) += br_netfilter.o
+
+bridge-$(CONFIG_BRIDGE_IGMP_SNOOPING) += br_multicast.o br_mdb.o br_multicast_eht.o
+
+bridge-$(CONFIG_BRIDGE_VLAN_FILTERING) += br_vlan.o br_vlan_tunnel.o br_vlan_options.o br_mst.o
+
+bridge-$(CONFIG_NET_SWITCHDEV) += br_switchdev.o
+
+obj-$(CONFIG_NETFILTER) += netfilter/
+
+bridge-$(CONFIG_BRIDGE_MRP)	+= br_mrp_switchdev.o br_mrp.o br_mrp_netlink.o
+
+bridge-$(CONFIG_BRIDGE_CFM)	+= br_cfm.o br_cfm_netlink.o
+
+ifdef CONFIG_GCOV_PROFILE_NETFILTER
+GCOV_PROFILE_br_nf_core.o := y
+GCOV_PROFILE_br_netfilter_hooks.o := y
+GCOV_PROFILE_br_netfilter_ipv6.o := y
+endif