security_inode_permission(9)

💅 security_inode_permission (Kernel API Manual, section 9)

Okay bestie, welcome to the Kernel API Manual corner of the internet — this one's a section 9 page, so it's a kernel-internals function, and it's genuinely iconic. Sit down, hydrate, let's go 🫶

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✨ NAME ✨

security_inode_permission — the vibe check that answers "are you actually allowed to touch this inode??" 💅

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🌸 SYNOPSIS 🌸

int security_inode_permission (struct inode *inode , int mask );

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🎀 ARGUMENTS 🎀

• inode — the inode. Like, the inode in question. That one. 📁
• mask — the access mask. The "what do you think you're doing with it" bitmask. 🎭

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🦋 DESCRIPTION 🦋

So here's the tea: this hook checks permission before anybody accesses an inode. It's called by the existing Linux permission function, which means a security module can hook in and add its own extra checking on top of the permission checks Linux already does. Basically the existing checks are the main character, and this hook is the bestie who double-checks their outfit before they leave the house ✨

And here's the detail people always get wrong, so listen up 👀 — this hook fires when a file is opened (plus a whole bunch of other operations too, fr fr). It is not the same as the file_security_ops permission hook, which is the one that gets called when the actual read/write operations are performed. Open time ≠ read/write time. Two different moments, two different hooks, don't mix them up iykyk 💀

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🔥 RETURN 🔥

Returns 0 if permission is granted. That's it. Zero means yes, go off, slay 👑

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🌈 SEE ALSO 🌈

It's in the kernel file ./security/security.c — and ngl, the see-also list here is long, like a group chat with everyone in it, so buckle up 🧚

lsm_file_alloc(9), lsm_backing_file_alloc(9), lsm_blob_alloc(9), lsm_cred_alloc(9), lsm_inode_alloc(9), lsm_task_alloc(9), lsm_ipc_alloc(9), lsm_key_alloc(9), lsm_msg_msg_alloc(9), lsm_bdev_alloc(9), lsm_bpf_map_alloc(9), lsm_bpf_prog_alloc(9), lsm_bpf_token_alloc(9), lsm_superblock_alloc(9), lsm_fill_user_ctx(9), security_binder_set_context_mgr(9), security_binder_transaction(9), security_binder_transfer_binder(9), security_binder_transfer_file(9), security_ptrace_access_check(9), security_ptrace_traceme(9), security_capget(9), security_capset(9), security_capable(9), security_quotactl(9), security_quota_on(9), security_syslog(9), security_settime64(9), security_vm_enough_memory_mm(9), security_bprm_creds_for_exec(9), security_bprm_creds_from_file(9), security_bprm_check(9), security_bprm_committing_creds(9), security_bprm_committed_creds(9), security_fs_context_submount(9), security_fs_context_dup(9), security_fs_context_parse_param(9), security_sb_alloc(9), security_sb_delete(9), security_sb_free(9), security_free_mnt_opts(9), security_sb_eat_lsm_opts(9), security_sb_mnt_opts_compat(9), security_sb_remount(9), security_sb_kern_mount(9), security_sb_show_options(9), security_sb_statfs(9), security_sb_mount(9), security_sb_umount(9), security_sb_pivotroot(9), security_sb_set_mnt_opts(9), security_sb_clone_mnt_opts(9), security_move_mount(9), security_path_notify(9), security_inode_alloc(9), security_inode_free(9), security_dentry_init_security(9), security_dentry_create_files_as(9), security_inode_init_security(9), security_inode_init_security_anon(9), security_path_mknod(9), security_path_post_mknod(9), security_path_mkdir(9), security_path_rmdir(9), security_path_unlink(9), security_path_symlink(9), security_path_link(9), security_path_rename(9), security_path_truncate(9), security_path_chmod(9), security_path_chown(9), security_path_chroot(9), security_inode_create(9), security_inode_post_create_tmpfile(9), security_inode_link(9), security_inode_unlink(9), security_inode_symlink(9), security_inode_mkdir(9), security_inode_rmdir(9), security_inode_mknod(9), security_inode_rename(9), security_inode_readlink(9), security_inode_follow_link(9), security_inode_setattr(9), security_inode_post_setattr(9), security_inode_getattr(9), security_inode_setxattr(9), security_inode_set_acl(9), security_inode_post_set_acl(9), security_inode_get_acl(9), security_inode_remove_acl(9), security_inode_post_remove_acl(9), security_inode_post_setxattr(9), security_inode_getxattr(9), security_inode_listxattr(9), security_inode_removexattr(9), security_inode_post_removexattr(9), security_inode_file_setattr(9), security_inode_file_getattr(9), security_inode_need_killpriv(9), security_inode_killpriv(9), security_inode_getsecurity(9), security_inode_setsecurity(9), security_inode_listsecurity(9), security_inode_getlsmprop(9), security_inode_copy_up(9), security_inode_copy_up_xattr(9), security_inode_setintegrity(9), security_kernfs_init_security(9), security_file_permission(9), security_file_alloc(9), security_file_release(9), security_file_free(9), security_backing_file_alloc(9), security_backing_file_free(9), security_file_ioctl(9), security_file_ioctl_compat(9), security_mmap_file(9), security_mmap_backing_file(9), security_mmap_addr(9), security_file_mprotect(9), security_file_lock(9), security_file_fcntl(9), security_file_set_fowner(9), security_file_send_sigiotask(9), security_file_receive(9), security_file_open(9), security_file_post_open(9), security_file_truncate(9), security_task_alloc(9), security_task_free(9), security_cred_alloc_blank(9), security_cred_free(9), security_prepare_creds(9), security_transfer_creds(9), security_cred_getsecid(9), security_cred_getlsmprop(9), security_kernel_act_as(9), security_kernel_create_files_as(9), security_kernel_module_request(9), security_kernel_read_file(9), security_kernel_post_read_file(9), security_kernel_load_data(9), security_kernel_post_load_data(9), security_task_fix_setuid(9), security_task_fix_setgid(9), security_task_fix_setgroups(9), security_task_setpgid(9), security_task_getpgid(9), security_task_getsid(9), security_current_getlsmprop_subj(9), security_task_getlsmprop_obj(9), security_task_setnice(9), security_task_setioprio(9), security_task_getioprio(9), security_task_prlimit(9), security_task_setrlimit(9), security_task_setscheduler(9), security_task_getscheduler(9), security_task_movememory(9), security_task_kill(9), security_task_prctl(9), security_task_to_inode(9), security_create_user_ns(9), security_ipc_permission(9), security_ipc_getlsmprop(9), security_msg_msg_alloc(9), security_msg_msg_free(9), security_msg_queue_alloc(9), security_msg_queue_free(9), security_msg_queue_associate(9), security_msg_queue_msgctl(9), security_msg_queue_msgsnd(9), security_msg_queue_msgrcv(9), security_shm_alloc(9), security_shm_free(9), security_shm_associate(9), security_shm_shmctl(9), security_shm_shmat(9), security_sem_alloc(9), security_sem_free(9), security_sem_associate(9), security_sem_semctl(9), security_sem_semop(9), security_d_instantiate(9), security_getselfattr(9), security_setselfattr(9), security_getprocattr(9), security_setprocattr(9), security_ismaclabel(9), security_secid_to_secctx(9), security_lsmprop_to_secctx(9), security_secctx_to_secid(9), security_release_secctx(9), security_inode_invalidate_secctx(9), security_inode_notifysecctx(9), security_inode_setsecctx(9), security_inode_getsecctx(9), security_post_notification(9), security_watch_key(9), security_netlink_send(9), security_unix_stream_connect(9), security_unix_may_send(9), security_socket_create(9), security_socket_post_create(9), security_socket_socketpair(9), security_socket_bind(9), security_socket_connect(9), security_socket_listen(9), security_socket_accept(9), security_socket_sendmsg(9), security_socket_recvmsg(9), security_socket_getsockname(9), security_socket_getpeername(9), security_socket_getsockopt(9), security_socket_setsockopt(9), security_socket_shutdown(9), security_sock_rcv_skb(9), security_socket_getpeersec_stream(9), security_socket_getpeersec_dgram(9), lsm_sock_alloc(9), security_sk_alloc(9), security_sk_free(9), security_sk_clone(9), security_sk_classify_flow(9), security_req_classify_flow(9), security_sock_graft(9), security_inet_conn_request(9), security_inet_csk_clone(9), security_inet_conn_established(9), security_secmark_relabel_packet(9), security_secmark_refcount_inc(9), security_secmark_refcount_dec(9), security_tun_dev_alloc_security(9), security_tun_dev_free_security(9), security_tun_dev_create(9), security_tun_dev_attach_queue(9), security_tun_dev_attach(9), security_tun_dev_open(9), security_sctp_assoc_request(9), security_sctp_bind_connect(9), security_sctp_sk_clone(9), security_sctp_assoc_established(9), security_mptcp_add_subflow(9), security_unix_find(9), security_ib_pkey_access(9), security_ib_endport_manage_subnet(9), security_ib_alloc_security(9), security_ib_free_security(9), security_xfrm_policy_alloc(9), security_xfrm_policy_clone(9), security_xfrm_policy_free(9), security_xfrm_policy_delete(9), security_xfrm_state_alloc(9), security_xfrm_state_alloc_acquire(9), security_xfrm_state_delete(9), security_xfrm_state_free(9), security_xfrm_policy_lookup(9), security_xfrm_state_pol_flow_match(9), security_xfrm_decode_session(9), security_key_alloc(9), security_key_free(9), security_key_permission(9), security_key_getsecurity(9), security_key_post_create_or_update(9), security_audit_rule_init(9), security_audit_rule_known(9), security_audit_rule_free(9), security_audit_rule_match(9), security_bpf(9), security_bpf_map(9), security_bpf_prog(9), security_bpf_map_create(9), security_bpf_prog_load(9), security_bpf_token_create(9), security_bpf_token_cmd(9), security_bpf_token_capable(9), security_bpf_map_free(9), security_bpf_prog_free(9), security_bpf_token_free(9), security_locked_down(9), security_bdev_alloc(9), security_bdev_free(9), security_bdev_setintegrity(9), security_perf_event_open(9), security_perf_event_alloc(9), security_perf_event_free(9), security_perf_event_read(9), security_perf_event_write(9), security_uring_override_creds(9), security_uring_sqpoll(9), security_uring_cmd(9), security_uring_allowed(9), security_initramfs_populated(9)

Yeah. All of them. Every single one. No skips, no cuts, we list the whole friend group 💜

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💖 That's the whole page, bestie — permission check at open time, extra checking for security modules, 0 means granted, and don't confuse it with file_security_ops. Periodt.

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And that's a wrap! 🎀 This lil' drop comes from the ./security source and is dated October 2026 — mwah, take care of her 💅✨