x86/amd_node: Fix PCI device reference counting in amd_smn_init()grafted

The local "root" pointer is a temporary variable used during the device
search. Therefore, refcount related to the search iterators should be cleaned
up after the search is complete.

Use the __free() cleanup macro to ensure the refcount is decremented when the
temporary pointer goes out of scope.

Additionally, increment the refcount when caching a root pointer. This ensures
the in-use refcount is separate from the temporary search refcounting.

Finally, drop the redundant "root = NULL" before the second search loop. The
pci_get_class() iterator always decrements the refcount of its "from"
argument, so the first loop can only fall through with "root" already NULL.

Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching")
Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com
Reported-by: Sashiko <sashiko-bot@kernel.org>
Assisted-by: LLM
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com

1 files changed, 105 insertions, 0 deletions

diff --git a/net/6lowpan/Kconfig b/net/6lowpan/Kconfig
new file mode 100644
index 000000000..d8fc45949
--- /dev/null
+++ b/net/6lowpan/Kconfig
@@ -0,0 +1,105 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menuconfig 6LOWPAN
+	tristate "6LoWPAN Support"
+	depends on IPV6
+	help
+	  This enables IPv6 over Low power Wireless Personal Area Network -
+	  "6LoWPAN" which is supported by IEEE 802.15.4 or Bluetooth stacks.
+
+config 6LOWPAN_DEBUGFS
+	bool "6LoWPAN debugfs support"
+	depends on 6LOWPAN
+	depends on DEBUG_FS
+	help
+	  This enables 6LoWPAN debugfs support. For example to manipulate
+	  IPHC context information at runtime.
+
+menuconfig 6LOWPAN_NHC
+	tristate "Next Header and Generic Header Compression Support"
+	depends on 6LOWPAN
+	default y
+	help
+	  Support for next header and generic header compression defined in
+	  RFC6282 and RFC7400.
+
+if 6LOWPAN_NHC
+
+config 6LOWPAN_NHC_DEST
+	tristate "Destination Options Header Support"
+	default y
+	help
+	  6LoWPAN IPv6 Destination Options Header compression according to
+	  RFC6282.
+
+config 6LOWPAN_NHC_FRAGMENT
+	tristate "Fragment Header Support"
+	default y
+	help
+	  6LoWPAN IPv6 Fragment Header compression according to RFC6282.
+
+config 6LOWPAN_NHC_HOP
+	tristate "Hop-by-Hop Options Header Support"
+	default y
+	help
+	  6LoWPAN IPv6 Hop-by-Hop Options Header compression according to
+	  RFC6282.
+
+config 6LOWPAN_NHC_IPV6
+	tristate "IPv6 Header Support"
+	default y
+	help
+	  6LoWPAN IPv6 Header compression according to RFC6282.
+
+config 6LOWPAN_NHC_MOBILITY
+	tristate "Mobility Header Support"
+	default y
+	help
+	  6LoWPAN IPv6 Mobility Header compression according to RFC6282.
+
+config 6LOWPAN_NHC_ROUTING
+	tristate "Routing Header Support"
+	default y
+	help
+	  6LoWPAN IPv6 Routing Header compression according to RFC6282.
+
+config 6LOWPAN_NHC_UDP
+	tristate "UDP Header Support"
+	default y
+	help
+	  6LoWPAN IPv6 UDP Header compression according to RFC6282.
+
+config 6LOWPAN_GHC_EXT_HDR_HOP
+	tristate "GHC Hop-by-Hop Options Header Support"
+	help
+	  6LoWPAN IPv6 Hop-by-Hop option generic header compression according
+	  to RFC7400.
+
+config 6LOWPAN_GHC_UDP
+	tristate "GHC UDP Support"
+	help
+	  6LoWPAN IPv6 UDP generic header compression according to RFC7400.
+
+config 6LOWPAN_GHC_ICMPV6
+	tristate "GHC ICMPv6 Support"
+	help
+	  6LoWPAN IPv6 ICMPv6 generic header compression according to RFC7400.
+
+config 6LOWPAN_GHC_EXT_HDR_DEST
+	tristate "GHC Destination Options Header Support"
+	help
+	  6LoWPAN IPv6 destination option generic header compression according
+	  to RFC7400.
+
+config 6LOWPAN_GHC_EXT_HDR_FRAG
+	tristate "GHC Fragmentation Options Header Support"
+	help
+	  6LoWPAN IPv6 fragmentation option generic header compression
+	  according to RFC7400.
+
+config 6LOWPAN_GHC_EXT_HDR_ROUTE
+	tristate "GHC Routing Options Header Support"
+	help
+	  6LoWPAN IPv6 routing option generic header compression according
+	  to RFC7400.
+
+endif