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, 49 insertions, 0 deletions

diff --git a/Documentation/crypto/libcrypto-unauth-encryption.rst b/Documentation/crypto/libcrypto-unauth-encryption.rst
new file mode 100644
index 000000000..b4639b892
--- /dev/null
+++ b/Documentation/crypto/libcrypto-unauth-encryption.rst
@@ -0,0 +1,49 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Unauthenticated encryption
+==========================
+
+These APIs provide support for unauthenticated encryption and decryption,
+including bare stream ciphers and other length-preserving algorithms such as
+block ciphers in XTS mode.  The legitimate use cases for these algorithms are:
+
+- Support for legacy protocols that really should have chosen an authenticated
+  mode (or even another primitive entirely) but didn't.
+
+- Internal components of authenticated modes.  For example, AES-CTR is used by
+  AES-GCM and AES-CCM internally.
+
+- Storage encryption that cannot accommodate ciphertext expansion.  Usually
+  AES-XTS is used for this.
+
+- Stream ciphers for key derivation and random number generation.
+
+Besides the above, these shouldn't be used.
+
+AES-CBC and AES-CBC-CTS
+-----------------------
+
+This API provides support for AES in the CBC and CBC-CTS modes of operation.
+
+.. kernel-doc:: include/crypto/aes-cbc.h
+
+AES-CTR and AES-XCTR
+--------------------
+
+This API provides support for AES in the CTR and XCTR modes of operation.
+
+.. kernel-doc:: include/crypto/aes-ctr.h
+
+AES-ECB
+-------
+
+This API provides support for AES in the ECB mode of operation.
+
+.. kernel-doc:: include/crypto/aes-ecb.h
+
+AES-XTS
+-------
+
+This API provides support for AES in the XTS mode of operation.
+
+.. kernel-doc:: include/crypto/aes-xts.h