From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() 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 Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- net/nfc/af_nfc.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) create mode 100644 net/nfc/af_nfc.c (limited to 'net/nfc/af_nfc.c') diff --git a/net/nfc/af_nfc.c b/net/nfc/af_nfc.c new file mode 100644 index 000000000..dda323e0a --- /dev/null +++ b/net/nfc/af_nfc.c @@ -0,0 +1,88 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2011 Instituto Nokia de Tecnologia + * + * Authors: + * Aloisio Almeida Jr + * Lauro Ramos Venancio + */ + +#include +#include + +#include "nfc.h" + +static DEFINE_RWLOCK(proto_tab_lock); +static const struct nfc_protocol *proto_tab[NFC_SOCKPROTO_MAX]; + +static int nfc_sock_create(struct net *net, struct socket *sock, int proto, + int kern) +{ + int rc = -EPROTONOSUPPORT; + + if (net != &init_net) + return -EAFNOSUPPORT; + + if (proto < 0 || proto >= NFC_SOCKPROTO_MAX) + return -EINVAL; + + read_lock(&proto_tab_lock); + if (proto_tab[proto] && try_module_get(proto_tab[proto]->owner)) { + rc = proto_tab[proto]->create(net, sock, proto_tab[proto], kern); + module_put(proto_tab[proto]->owner); + } + read_unlock(&proto_tab_lock); + + return rc; +} + +static const struct net_proto_family nfc_sock_family_ops = { + .owner = THIS_MODULE, + .family = PF_NFC, + .create = nfc_sock_create, +}; + +int nfc_proto_register(const struct nfc_protocol *nfc_proto) +{ + int rc; + + if (nfc_proto->id < 0 || nfc_proto->id >= NFC_SOCKPROTO_MAX) + return -EINVAL; + + rc = proto_register(nfc_proto->proto, 0); + if (rc) + return rc; + + write_lock(&proto_tab_lock); + if (proto_tab[nfc_proto->id]) + rc = -EBUSY; + else + proto_tab[nfc_proto->id] = nfc_proto; + write_unlock(&proto_tab_lock); + + if (rc) + proto_unregister(nfc_proto->proto); + + return rc; +} +EXPORT_SYMBOL(nfc_proto_register); + +void nfc_proto_unregister(const struct nfc_protocol *nfc_proto) +{ + write_lock(&proto_tab_lock); + proto_tab[nfc_proto->id] = NULL; + write_unlock(&proto_tab_lock); + + proto_unregister(nfc_proto->proto); +} +EXPORT_SYMBOL(nfc_proto_unregister); + +int __init af_nfc_init(void) +{ + return sock_register(&nfc_sock_family_ops); +} + +void __exit af_nfc_exit(void) +{ + sock_unregister(PF_NFC); +} -- cgit v1.3.1