smack_file_fcntl(9)

💅 smack_file_fcntl(9) — Smack check on fcntl 💅

okay so bestie, welcome to the Kernel API Manual page for smack_file_fcntl(9). This one is the Smack check on fcntl, and it's lowkey a tiny little gatekeeper. Let's get into it 🫶

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✨ NAME ✨

smack_file_fcntl — Smack check on fcntl

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🦋 SYNOPSIS 🦋

int smack_file_fcntl (struct file *file , unsigned int cmd , unsigned
long arg );

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🎀 ARGUMENTS 🎀

• file — the object
• cmd — what action to check
• arg — unused

real talk: arg is unused here, so don't make it a whole main character. It's just vibing 🙈

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🌸 DESCRIPTION 🌸

Generally these operations are harmless. File locking operations present an obvious mechanism for passing information, so they require write access.

Returns 0 if current has access, error code otherwise.

so basically: most of the time it's chill, but file locking ops are giving information-passing tunnel realness, and they need write access. periodt 💅

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🔥 SEE ALSO 🔥

Kernel file: ./security/smack/smack_lsm.c

and the whole Smack extended-fam lineup, exactly as listed:

smk_fetch(9), init_inode_smack(9), init_task_smack(9), smk_copy_rules(9),
smk_copy_relabel(9), smk_ptrace_mode(9), smk_ptrace_rule_check(9),
smack_ptrace_access_check(9), smack_ptrace_traceme(9), smack_syslog(9),
smack_sb_alloc_security(9), smack_fs_context_submount(9),
smack_fs_context_dup(9), smack_fs_context_parse_param(9),
smack_set_mnt_opts(9), smack_sb_statfs(9), smack_bprm_creds_for_exec(9),
smack_inode_alloc_security(9), smk_rule_transmutes(9),
smack_inode_init_security(9), smack_inode_link(9),
smack_inode_unlink(9), smack_inode_rmdir(9), smack_inode_rename(9),
smack_inode_permission(9), smack_inode_setattr(9),
smack_inode_getattr(9), smack_inode_xattr_skipcap(9),
smack_inode_setxattr(9), smack_inode_post_setxattr(9),
smack_inode_getxattr(9), smack_inode_removexattr(9),
smack_inode_set_acl(9), smack_inode_get_acl(9),
smack_inode_remove_acl(9), smack_inode_getsecurity(9),
smack_inode_listsecurity(9), smack_inode_getlsmprop(9),
smack_file_alloc_security(9), smack_file_ioctl(9), smack_file_lock(9),
smack_mmap_file(9), smack_file_set_fowner(9),
smack_file_send_sigiotask(9), smack_file_receive(9), smack_file_open(9),
smack_cred_alloc_blank(9), smack_cred_free(9), smack_cred_prepare(9),
smack_cred_transfer(9), smack_cred_getsecid(9),
smack_cred_getlsmprop(9), smack_kernel_act_as(9),
smack_kernel_create_files_as(9), smk_curacc_on_task(9),
smack_task_setpgid(9), smack_task_getpgid(9), smack_task_getsid(9),
smack_current_getlsmprop_subj(9), smack_task_getlsmprop_obj(9),
smack_task_setnice(9), smack_task_setioprio(9), smack_task_getioprio(9),
smack_task_setscheduler(9), smack_task_getscheduler(9),
smack_task_movememory(9), smack_task_kill(9), smack_task_to_inode(9),
smack_sk_alloc_security(9), smack_sk_free_security(9),
smack_sk_clone_security(9), smack_ipv4host_label(9),
smack_ipv6host_label(9), smack_netlbl_add(9), smack_netlbl_delete(9),
smk_ipv4_check(9), smk_ipv6_check(9), smk_ipv6_port_label(9),
smk_ipv6_port_check(9), smack_inode_setsecurity(9),
smack_socket_post_create(9), smack_socket_socketpair(9),
smack_socket_bind(9), smack_socket_connect(9), smack_flags_to_may(9),
smack_msg_msg_alloc_security(9), smack_of_ipc(9),
smack_ipc_alloc_security(9), smk_curacc_shm(9), smack_shm_associate(9),
smack_shm_shmctl(9), smack_shm_shmat(9), smk_curacc_sem(9),
smack_sem_associate(9), smack_sem_semctl(9), smack_sem_semop(9),
smk_tskacc_msq(9), smk_curacc_msq(9), smack_msg_queue_associate(9),
smack_msg_queue_msgctl(9), smack_msg_queue_msgsnd(9),
smack_msg_queue_msgrcv(9), smack_ipc_permission(9),
smack_ipc_getlsmprop(9), smack_d_instantiate(9), smack_getselfattr(9),
smack_getprocattr(9), do_setattr(9), smack_setselfattr(9),
smack_setprocattr(9), smack_unix_stream_connect(9),
smack_unix_may_send(9), smack_socket_sendmsg(9), smack_from_secattr(9),
smack_from_skb(9), smack_from_netlbl(9), smack_socket_sock_rcv_skb(9),
smack_socket_getpeersec_stream(9), smack_socket_getpeersec_dgram(9),
smack_inet_conn_request(9), smack_inet_csk_clone(9), smack_key_alloc(9),
smack_key_permission(9), smack_watch_key(9), smack_post_notification(9),
smack_audit_rule_init(9), smack_audit_rule_known(9),
smack_audit_rule_match(9), smack_ismaclabel(9), smack_to_secctx(9),
smack_secid_to_secctx(9), smack_lsmprop_to_secctx(9),
smack_secctx_to_secid(9), smack_uring_override_creds(9),
smack_uring_sqpoll(9), smack_uring_cmd(9), smack_init(9)

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byeee bestie 💖 — source/version ./security/smack, stamped October 2026, page smack_file_fcntl(9). mwah 💋