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 --- lib/crypto/mpi/mpi-sub-ui.c | 80 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 lib/crypto/mpi/mpi-sub-ui.c (limited to 'lib/crypto/mpi/mpi-sub-ui.c') diff --git a/lib/crypto/mpi/mpi-sub-ui.c b/lib/crypto/mpi/mpi-sub-ui.c new file mode 100644 index 000000000..0edcdbd24 --- /dev/null +++ b/lib/crypto/mpi/mpi-sub-ui.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* mpi-sub-ui.c - Subtract an unsigned integer from an MPI. + * + * Copyright 1991, 1993, 1994, 1996, 1999-2002, 2004, 2012, 2013, 2015 + * Free Software Foundation, Inc. + * + * This file was based on the GNU MP Library source file: + * https://gmplib.org/repo/gmp-6.2/file/510b83519d1c/mpz/aors_ui.h + * + * The GNU MP Library is free software; you can redistribute it and/or modify + * it under the terms of either: + * + * * the GNU Lesser General Public License as published by the Free + * Software Foundation; either version 3 of the License, or (at your + * option) any later version. + * + * or + * + * * the GNU General Public License as published by the Free Software + * Foundation; either version 2 of the License, or (at your option) any + * later version. + * + * or both in parallel, as here. + * + * The GNU MP Library is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + * + * You should have received copies of the GNU General Public License and the + * GNU Lesser General Public License along with the GNU MP Library. If not, + * see https://www.gnu.org/licenses/. + */ + +#include + +#include "mpi-internal.h" + +int mpi_sub_ui(MPI w, MPI u, unsigned long vval) +{ + if (u->nlimbs == 0) { + if (mpi_resize(w, 1) < 0) + return -ENOMEM; + w->d[0] = vval; + w->nlimbs = (vval != 0); + w->sign = (vval != 0); + return 0; + } + + /* If not space for W (and possible carry), increase space. */ + if (mpi_resize(w, u->nlimbs + 1)) + return -ENOMEM; + + if (u->sign) { + mpi_limb_t cy; + + cy = mpihelp_add_1(w->d, u->d, u->nlimbs, (mpi_limb_t) vval); + w->d[u->nlimbs] = cy; + w->nlimbs = u->nlimbs + cy; + w->sign = 1; + } else { + /* The signs are different. Need exact comparison to determine + * which operand to subtract from which. + */ + if (u->nlimbs == 1 && u->d[0] < vval) { + w->d[0] = vval - u->d[0]; + w->nlimbs = 1; + w->sign = 1; + } else { + mpihelp_sub_1(w->d, u->d, u->nlimbs, (mpi_limb_t) vval); + /* Size can decrease with at most one limb. */ + w->nlimbs = (u->nlimbs - (w->d[u->nlimbs - 1] == 0)); + w->sign = 0; + } + } + + mpi_normalize(w); + return 0; +} +EXPORT_SYMBOL_GPL(mpi_sub_ui); -- cgit v1.3.1