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, 66 insertions, 0 deletions

diff --git a/Documentation/usb/linux.inf b/Documentation/usb/linux.inf
new file mode 100644
index 000000000..c569ac6be
--- /dev/null
+++ b/Documentation/usb/linux.inf
@@ -0,0 +1,66 @@
+; Based on template INF file found at
+;    <https://msdn.microsoft.com/en-us/library/ff570620.aspx>
+; which was:
+;    Copyright (c) Microsoft Corporation
+; and released under the MLPL as found at:
+;    <http://msdn.microsoft.com/en-us/cc300389.aspx#MLPL>.
+; For use only on Windows operating systems.
+
+[Version]
+Signature           = "$Windows NT$"
+Class               = Net
+ClassGUID           = {4d36e972-e325-11ce-bfc1-08002be10318}
+Provider            = %Linux%
+DriverVer           = 06/21/2006,6.0.6000.16384
+
+[Manufacturer]
+%Linux%             = LinuxDevices,NTx86,NTamd64,NTia64
+
+; Decoration for x86 architecture
+[LinuxDevices.NTx86]
+%LinuxDevice%       = RNDIS.NT.5.1, USB\VID_0525&PID_a4a2, USB\VID_1d6b&PID_0104&MI_00
+
+; Decoration for x64 architecture
+[LinuxDevices.NTamd64]
+%LinuxDevice%       = RNDIS.NT.5.1, USB\VID_0525&PID_a4a2, USB\VID_1d6b&PID_0104&MI_00
+
+; Decoration for ia64 architecture
+[LinuxDevices.NTia64]
+%LinuxDevice%       = RNDIS.NT.5.1, USB\VID_0525&PID_a4a2, USB\VID_1d6b&PID_0104&MI_00
+
+;@@@ This is the common setting for setup
+[ControlFlags]
+ExcludeFromSelect=*
+
+; DDInstall section
+; References the in-build Netrndis.inf
+[RNDIS.NT.5.1]
+Characteristics     = 0x84   ; NCF_PHYSICAL + NCF_HAS_UI
+BusType             = 15
+; NEVER REMOVE THE FOLLOWING REFERENCE FOR NETRNDIS.INF
+include             = netrndis.inf
+needs               = Usb_Rndis.ndi
+AddReg              = Rndis_AddReg_Vista
+
+; DDInstal.Services section
+[RNDIS.NT.5.1.Services]
+include             = netrndis.inf
+needs               = Usb_Rndis.ndi.Services
+
+; Optional registry settings. You can modify as needed.
+[RNDIS_AddReg_Vista]
+HKR, NDI\params\VistaProperty, ParamDesc,  0, %Vista_Property%
+HKR, NDI\params\VistaProperty, type,       0, "edit"
+HKR, NDI\params\VistaProperty, LimitText,  0, "12"
+HKR, NDI\params\VistaProperty, UpperCase,  0, "1"
+HKR, NDI\params\VistaProperty, default,    0, " "
+HKR, NDI\params\VistaProperty, optional,   0, "1"
+
+; No sys copyfiles - the sys files are already in-build
+; (part of the operating system).
+; We do not support XP SP1-, 2003 SP1-, ME, 9x.
+
+[Strings]
+Linux                 = "Linux Developer Community"
+LinuxDevice           = "Linux USB Ethernet/RNDIS Gadget"
+Vista_Property        = "Optional Vista Property"