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 --- fs/lockd/svcshare.c | 151 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 151 insertions(+) create mode 100644 fs/lockd/svcshare.c (limited to 'fs/lockd/svcshare.c') diff --git a/fs/lockd/svcshare.c b/fs/lockd/svcshare.c new file mode 100644 index 000000000..a58b7035b --- /dev/null +++ b/fs/lockd/svcshare.c @@ -0,0 +1,151 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/fs/lockd/svcshare.c + * + * Management of DOS shares. + * + * Copyright (C) 1996 Olaf Kirch + */ + +#include +#include +#include +#include + +#include +#include + +#include "lockd.h" +#include "share.h" + +static inline int +nlm_cmp_owner(struct lockd_share *share, struct xdr_netobj *oh) +{ + return share->s_owner.len == oh->len + && !memcmp(share->s_owner.data, oh->data, oh->len); +} + +/* + * Recompute s_access / s_mode as the union of every (access, deny) pair + * whose bit is currently set in s_access_deny_bmap. + */ +static void nlm_recompute_share(struct lockd_share *share) +{ + u32 new_access = 0, new_mode = 0; + unsigned int i; + + for (i = 0; i < 16; i++) { + if (share->s_access_deny_bmap & BIT(i)) { + new_access |= i >> 2; + new_mode |= i & 3; + } + } + share->s_access = new_access; + share->s_mode = new_mode; +} + +/** + * nlmsvc_share_file - create a share + * @host: Network client peer + * @file: File to be shared + * @oh: Share owner handle + * @access: Requested access mode + * @mode: Requested file sharing mode + * + * Returns an NLM status code. + */ +__be32 +nlmsvc_share_file(struct nlm_host *host, struct nlm_file *file, + struct xdr_netobj *oh, u32 access, u32 mode) +{ + struct lockd_share *share; + u8 *ohdata; + + if (nlmsvc_file_cannot_lock(file)) + return nlm_lck_denied_nolocks; + + for (share = file->f_shares; share; share = share->s_next) { + if (share->s_host == host && nlm_cmp_owner(share, oh)) + goto update; + if ((access & share->s_mode) || (mode & share->s_access)) + return nlm_lck_denied; + } + + share = kmalloc(sizeof(*share) + oh->len, GFP_KERNEL); + if (share == NULL) + return nlm_lck_denied_nolocks; + + /* Copy owner handle */ + ohdata = (u8 *) (share + 1); + memcpy(ohdata, oh->data, oh->len); + + share->s_file = file; + share->s_host = host; + share->s_owner.data = ohdata; + share->s_owner.len = oh->len; + share->s_access_deny_bmap = 0; + share->s_next = file->f_shares; + file->f_shares = share; + +update: + share->s_access_deny_bmap |= LOCKD_FSH_BIT(access, mode); + nlm_recompute_share(share); + return nlm_granted; +} + +/** + * nlmsvc_unshare_file - delete a share + * @host: Network client peer + * @file: File to be unshared + * @oh: Share owner handle + * @access: Access mode of the SHARE being released + * @mode: Deny mode of the SHARE being released + * + * Returns an NLM status code. + */ +__be32 +nlmsvc_unshare_file(struct nlm_host *host, struct nlm_file *file, + struct xdr_netobj *oh, u32 access, u32 mode) +{ + struct lockd_share *share, **shpp; + + if (nlmsvc_file_cannot_lock(file)) + return nlm_lck_denied_nolocks; + + for (shpp = &file->f_shares; (share = *shpp) != NULL; + shpp = &share->s_next) { + if (share->s_host == host && nlm_cmp_owner(share, oh)) { + share->s_access_deny_bmap &= ~LOCKD_FSH_BIT(access, mode); + nlm_recompute_share(share); + if (!share->s_access_deny_bmap) { + *shpp = share->s_next; + kfree(share); + } + return nlm_granted; + } + } + + /* X/Open spec says return success even if there was no + * corresponding share. */ + return nlm_granted; +} + +/* + * Traverse all shares for a given file, and delete + * those owned by the given (type of) host + */ +void nlmsvc_traverse_shares(struct nlm_host *host, struct nlm_file *file, + nlm_host_match_fn_t match) +{ + struct lockd_share *share, **shpp; + + shpp = &file->f_shares; + while ((share = *shpp) != NULL) { + if (match(share->s_host, host)) { + *shpp = share->s_next; + kfree(share); + continue; + } + shpp = &share->s_next; + } +} -- cgit v1.3.1