Merge branch 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull general security layer updates from James Morris:

 - Convert security hooks from list to hlist, a nice cleanup, saving
   about 50% of space, from Sargun Dhillon.

 - Only pass the cred, not the secid, to kill_pid_info_as_cred and
   security_task_kill (as the secid can be determined from the cred),
   from Stephen Smalley.

 - Close a potential race in kernel_read_file(), by making the file
   unwritable before calling the LSM check (vs after), from Kees Cook.

* 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  security: convert security hooks to use hlist
  exec: Set file unwritable before LSM check
  usb, signal, security: only pass the cred, not the secid, to kill_pid_info_as_cred and security_task_kill

3 files changed, 223 insertions, 222 deletions

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 6e6951b42be5..c72c42dbe77b 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -672,7 +672,8 @@
  *	@p contains the task_struct for process.
  *	@info contains the signal information.
  *	@sig contains the signal value.
- *	@secid contains the sid of the process where the signal originated
+ *	@cred contains the cred of the process where the signal originated, or
+ *	NULL if the current task is the originator.
  *	Return 0 if permission is granted.
  * @task_prctl:
  *	Check permission before performing a process control operation on the
@@ -1591,7 +1592,7 @@ union security_list_options {
 	int (*task_getscheduler)(struct task_struct *p);
 	int (*task_movememory)(struct task_struct *p);
 	int (*task_kill)(struct task_struct *p, struct siginfo *info,
-				int sig, u32 secid);
+				int sig, const struct cred *cred);
 	int (*task_prctl)(int option, unsigned long arg2, unsigned long arg3,
 				unsigned long arg4, unsigned long arg5);
 	void (*task_to_inode)(struct task_struct *p, struct inode *inode);
@@ -1763,233 +1764,233 @@ union security_list_options {
 };
 
 struct security_hook_heads {
-	struct list_head binder_set_context_mgr;
-	struct list_head binder_transaction;
-	struct list_head binder_transfer_binder;
-	struct list_head binder_transfer_file;
-	struct list_head ptrace_access_check;
-	struct list_head ptrace_traceme;
-	struct list_head capget;
-	struct list_head capset;
-	struct list_head capable;
-	struct list_head quotactl;
-	struct list_head quota_on;
-	struct list_head syslog;
-	struct list_head settime;
-	struct list_head vm_enough_memory;
-	struct list_head bprm_set_creds;
-	struct list_head bprm_check_security;
-	struct list_head bprm_committing_creds;
-	struct list_head bprm_committed_creds;
-	struct list_head sb_alloc_security;
-	struct list_head sb_free_security;
-	struct list_head sb_copy_data;
-	struct list_head sb_remount;
-	struct list_head sb_kern_mount;
-	struct list_head sb_show_options;
-	struct list_head sb_statfs;
-	struct list_head sb_mount;
-	struct list_head sb_umount;
-	struct list_head sb_pivotroot;
-	struct list_head sb_set_mnt_opts;
-	struct list_head sb_clone_mnt_opts;
-	struct list_head sb_parse_opts_str;
-	struct list_head dentry_init_security;
-	struct list_head dentry_create_files_as;
+	struct hlist_head binder_set_context_mgr;
+	struct hlist_head binder_transaction;
+	struct hlist_head binder_transfer_binder;
+	struct hlist_head binder_transfer_file;
+	struct hlist_head ptrace_access_check;
+	struct hlist_head ptrace_traceme;
+	struct hlist_head capget;
+	struct hlist_head capset;
+	struct hlist_head capable;
+	struct hlist_head quotactl;
+	struct hlist_head quota_on;
+	struct hlist_head syslog;
+	struct hlist_head settime;
+	struct hlist_head vm_enough_memory;
+	struct hlist_head bprm_set_creds;
+	struct hlist_head bprm_check_security;
+	struct hlist_head bprm_committing_creds;
+	struct hlist_head bprm_committed_creds;
+	struct hlist_head sb_alloc_security;
+	struct hlist_head sb_free_security;
+	struct hlist_head sb_copy_data;
+	struct hlist_head sb_remount;
+	struct hlist_head sb_kern_mount;
+	struct hlist_head sb_show_options;
+	struct hlist_head sb_statfs;
+	struct hlist_head sb_mount;
+	struct hlist_head sb_umount;
+	struct hlist_head sb_pivotroot;
+	struct hlist_head sb_set_mnt_opts;
+	struct hlist_head sb_clone_mnt_opts;
+	struct hlist_head sb_parse_opts_str;
+	struct hlist_head dentry_init_security;
+	struct hlist_head dentry_create_files_as;
 #ifdef CONFIG_SECURITY_PATH
-	struct list_head path_unlink;
-	struct list_head path_mkdir;
-	struct list_head path_rmdir;
-	struct list_head path_mknod;
-	struct list_head path_truncate;
-	struct list_head path_symlink;
-	struct list_head path_link;
-	struct list_head path_rename;
-	struct list_head path_chmod;
-	struct list_head path_chown;
-	struct list_head path_chroot;
+	struct hlist_head path_unlink;
+	struct hlist_head path_mkdir;
+	struct hlist_head path_rmdir;
+	struct hlist_head path_mknod;
+	struct hlist_head path_truncate;
+	struct hlist_head path_symlink;
+	struct hlist_head path_link;
+	struct hlist_head path_rename;
+	struct hlist_head path_chmod;
+	struct hlist_head path_chown;
+	struct hlist_head path_chroot;
 #endif
-	struct list_head inode_alloc_security;
-	struct list_head inode_free_security;
-	struct list_head inode_init_security;
-	struct list_head inode_create;
-	struct list_head inode_link;
-	struct list_head inode_unlink;
-	struct list_head inode_symlink;
-	struct list_head inode_mkdir;
-	struct list_head inode_rmdir;
-	struct list_head inode_mknod;
-	struct list_head inode_rename;
-	struct list_head inode_readlink;
-	struct list_head inode_follow_link;
-	struct list_head inode_permission;
-	struct list_head inode_setattr;
-	struct list_head inode_getattr;
-	struct list_head inode_setxattr;
-	struct list_head inode_post_setxattr;
-	struct list_head inode_getxattr;
-	struct list_head inode_listxattr;
-	struct list_head inode_removexattr;
-	struct list_head inode_need_killpriv;
-	struct list_head inode_killpriv;
-	struct list_head inode_getsecurity;
-	struct list_head inode_setsecurity;
-	struct list_head inode_listsecurity;
-	struct list_head inode_getsecid;
-	struct list_head inode_copy_up;
-	struct list_head inode_copy_up_xattr;
-	struct list_head file_permission;
-	struct list_head file_alloc_security;
-	struct list_head file_free_security;
-	struct list_head file_ioctl;
-	struct list_head mmap_addr;
-	struct list_head mmap_file;
-	struct list_head file_mprotect;
-	struct list_head file_lock;
-	struct list_head file_fcntl;
-	struct list_head file_set_fowner;
-	struct list_head file_send_sigiotask;
-	struct list_head file_receive;
-	struct list_head file_open;
-	struct list_head task_alloc;
-	struct list_head task_free;
-	struct list_head cred_alloc_blank;
-	struct list_head cred_free;
-	struct list_head cred_prepare;
-	struct list_head cred_transfer;
-	struct list_head kernel_act_as;
-	struct list_head kernel_create_files_as;
-	struct list_head kernel_read_file;
-	struct list_head kernel_post_read_file;
-	struct list_head kernel_module_request;
-	struct list_head task_fix_setuid;
-	struct list_head task_setpgid;
-	struct list_head task_getpgid;
-	struct list_head task_getsid;
-	struct list_head task_getsecid;
-	struct list_head task_setnice;
-	struct list_head task_setioprio;
-	struct list_head task_getioprio;
-	struct list_head task_prlimit;
-	struct list_head task_setrlimit;
-	struct list_head task_setscheduler;
-	struct list_head task_getscheduler;
-	struct list_head task_movememory;
-	struct list_head task_kill;
-	struct list_head task_prctl;
-	struct list_head task_to_inode;
-	struct list_head ipc_permission;
-	struct list_head ipc_getsecid;
-	struct list_head msg_msg_alloc_security;
-	struct list_head msg_msg_free_security;
-	struct list_head msg_queue_alloc_security;
-	struct list_head msg_queue_free_security;
-	struct list_head msg_queue_associate;
-	struct list_head msg_queue_msgctl;
-	struct list_head msg_queue_msgsnd;
-	struct list_head msg_queue_msgrcv;
-	struct list_head shm_alloc_security;
-	struct list_head shm_free_security;
-	struct list_head shm_associate;
-	struct list_head shm_shmctl;
-	struct list_head shm_shmat;
-	struct list_head sem_alloc_security;
-	struct list_head sem_free_security;
-	struct list_head sem_associate;
-	struct list_head sem_semctl;
-	struct list_head sem_semop;
-	struct list_head netlink_send;
-	struct list_head d_instantiate;
-	struct list_head getprocattr;
-	struct list_head setprocattr;
-	struct list_head ismaclabel;
-	struct list_head secid_to_secctx;
-	struct list_head secctx_to_secid;
-	struct list_head release_secctx;
-	struct list_head inode_invalidate_secctx;
-	struct list_head inode_notifysecctx;
-	struct list_head inode_setsecctx;
-	struct list_head inode_getsecctx;
+	struct hlist_head inode_alloc_security;
+	struct hlist_head inode_free_security;
+	struct hlist_head inode_init_security;
+	struct hlist_head inode_create;
+	struct hlist_head inode_link;
+	struct hlist_head inode_unlink;
+	struct hlist_head inode_symlink;
+	struct hlist_head inode_mkdir;
+	struct hlist_head inode_rmdir;
+	struct hlist_head inode_mknod;
+	struct hlist_head inode_rename;
+	struct hlist_head inode_readlink;
+	struct hlist_head inode_follow_link;
+	struct hlist_head inode_permission;
+	struct hlist_head inode_setattr;
+	struct hlist_head inode_getattr;
+	struct hlist_head inode_setxattr;
+	struct hlist_head inode_post_setxattr;
+	struct hlist_head inode_getxattr;
+	struct hlist_head inode_listxattr;
+	struct hlist_head inode_removexattr;
+	struct hlist_head inode_need_killpriv;
+	struct hlist_head inode_killpriv;
+	struct hlist_head inode_getsecurity;
+	struct hlist_head inode_setsecurity;
+	struct hlist_head inode_listsecurity;
+	struct hlist_head inode_getsecid;
+	struct hlist_head inode_copy_up;
+	struct hlist_head inode_copy_up_xattr;
+	struct hlist_head file_permission;
+	struct hlist_head file_alloc_security;
+	struct hlist_head file_free_security;
+	struct hlist_head file_ioctl;
+	struct hlist_head mmap_addr;
+	struct hlist_head mmap_file;
+	struct hlist_head file_mprotect;
+	struct hlist_head file_lock;
+	struct hlist_head file_fcntl;
+	struct hlist_head file_set_fowner;
+	struct hlist_head file_send_sigiotask;
+	struct hlist_head file_receive;
+	struct hlist_head file_open;
+	struct hlist_head task_alloc;
+	struct hlist_head task_free;
+	struct hlist_head cred_alloc_blank;
+	struct hlist_head cred_free;
+	struct hlist_head cred_prepare;
+	struct hlist_head cred_transfer;
+	struct hlist_head kernel_act_as;
+	struct hlist_head kernel_create_files_as;
+	struct hlist_head kernel_read_file;
+	struct hlist_head kernel_post_read_file;
+	struct hlist_head kernel_module_request;
+	struct hlist_head task_fix_setuid;
+	struct hlist_head task_setpgid;
+	struct hlist_head task_getpgid;
+	struct hlist_head task_getsid;
+	struct hlist_head task_getsecid;
+	struct hlist_head task_setnice;
+	struct hlist_head task_setioprio;
+	struct hlist_head task_getioprio;
+	struct hlist_head task_prlimit;
+	struct hlist_head task_setrlimit;
+	struct hlist_head task_setscheduler;
+	struct hlist_head task_getscheduler;
+	struct hlist_head task_movememory;
+	struct hlist_head task_kill;
+	struct hlist_head task_prctl;
+	struct hlist_head task_to_inode;
+	struct hlist_head ipc_permission;
+	struct hlist_head ipc_getsecid;
+	struct hlist_head msg_msg_alloc_security;
+	struct hlist_head msg_msg_free_security;
+	struct hlist_head msg_queue_alloc_security;
+	struct hlist_head msg_queue_free_security;
+	struct hlist_head msg_queue_associate;
+	struct hlist_head msg_queue_msgctl;
+	struct hlist_head msg_queue_msgsnd;
+	struct hlist_head msg_queue_msgrcv;
+	struct hlist_head shm_alloc_security;
+	struct hlist_head shm_free_security;
+	struct hlist_head shm_associate;
+	struct hlist_head shm_shmctl;
+	struct hlist_head shm_shmat;
+	struct hlist_head sem_alloc_security;
+	struct hlist_head sem_free_security;
+	struct hlist_head sem_associate;
+	struct hlist_head sem_semctl;
+	struct hlist_head sem_semop;
+	struct hlist_head netlink_send;
+	struct hlist_head d_instantiate;
+	struct hlist_head getprocattr;
+	struct hlist_head setprocattr;
+	struct hlist_head ismaclabel;
+	struct hlist_head secid_to_secctx;
+	struct hlist_head secctx_to_secid;
+	struct hlist_head release_secctx;
+	struct hlist_head inode_invalidate_secctx;
+	struct hlist_head inode_notifysecctx;
+	struct hlist_head inode_setsecctx;
+	struct hlist_head inode_getsecctx;
 #ifdef CONFIG_SECURITY_NETWORK
-	struct list_head unix_stream_connect;
-	struct list_head unix_may_send;
-	struct list_head socket_create;
-	struct list_head socket_post_create;
-	struct list_head socket_bind;
-	struct list_head socket_connect;
-	struct list_head socket_listen;
-	struct list_head socket_accept;
-	struct list_head socket_sendmsg;
-	struct list_head socket_recvmsg;
-	struct list_head socket_getsockname;
-	struct list_head socket_getpeername;
-	struct list_head socket_getsockopt;
-	struct list_head socket_setsockopt;
-	struct list_head socket_shutdown;
-	struct list_head socket_sock_rcv_skb;
-	struct list_head socket_getpeersec_stream;
-	struct list_head socket_getpeersec_dgram;
-	struct list_head sk_alloc_security;
-	struct list_head sk_free_security;
-	struct list_head sk_clone_security;
-	struct list_head sk_getsecid;
-	struct list_head sock_graft;
-	struct list_head inet_conn_request;
-	struct list_head inet_csk_clone;
-	struct list_head inet_conn_established;
-	struct list_head secmark_relabel_packet;
-	struct list_head secmark_refcount_inc;
-	struct list_head secmark_refcount_dec;
-	struct list_head req_classify_flow;
-	struct list_head tun_dev_alloc_security;
-	struct list_head tun_dev_free_security;
-	struct list_head tun_dev_create;
-	struct list_head tun_dev_attach_queue;
-	struct list_head tun_dev_attach;
-	struct list_head tun_dev_open;
-	struct list_head sctp_assoc_request;
-	struct list_head sctp_bind_connect;
-	struct list_head sctp_sk_clone;
+	struct hlist_head unix_stream_connect;
+	struct hlist_head unix_may_send;
+	struct hlist_head socket_create;
+	struct hlist_head socket_post_create;
+	struct hlist_head socket_bind;
+	struct hlist_head socket_connect;
+	struct hlist_head socket_listen;
+	struct hlist_head socket_accept;
+	struct hlist_head socket_sendmsg;
+	struct hlist_head socket_recvmsg;
+	struct hlist_head socket_getsockname;
+	struct hlist_head socket_getpeername;
+	struct hlist_head socket_getsockopt;
+	struct hlist_head socket_setsockopt;
+	struct hlist_head socket_shutdown;
+	struct hlist_head socket_sock_rcv_skb;
+	struct hlist_head socket_getpeersec_stream;
+	struct hlist_head socket_getpeersec_dgram;
+	struct hlist_head sk_alloc_security;
+	struct hlist_head sk_free_security;
+	struct hlist_head sk_clone_security;
+	struct hlist_head sk_getsecid;
+	struct hlist_head sock_graft;
+	struct hlist_head inet_conn_request;
+	struct hlist_head inet_csk_clone;
+	struct hlist_head inet_conn_established;
+	struct hlist_head secmark_relabel_packet;
+	struct hlist_head secmark_refcount_inc;
+	struct hlist_head secmark_refcount_dec;
+	struct hlist_head req_classify_flow;
+	struct hlist_head tun_dev_alloc_security;
+	struct hlist_head tun_dev_free_security;
+	struct hlist_head tun_dev_create;
+	struct hlist_head tun_dev_attach_queue;
+	struct hlist_head tun_dev_attach;
+	struct hlist_head tun_dev_open;
+	struct hlist_head sctp_assoc_request;
+	struct hlist_head sctp_bind_connect;
+	struct hlist_head sctp_sk_clone;
 #endif	/* CONFIG_SECURITY_NETWORK */
 #ifdef CONFIG_SECURITY_INFINIBAND
-	struct list_head ib_pkey_access;
-	struct list_head ib_endport_manage_subnet;
-	struct list_head ib_alloc_security;
-	struct list_head ib_free_security;
+	struct hlist_head ib_pkey_access;
+	struct hlist_head ib_endport_manage_subnet;
+	struct hlist_head ib_alloc_security;
+	struct hlist_head ib_free_security;
 #endif	/* CONFIG_SECURITY_INFINIBAND */
 #ifdef CONFIG_SECURITY_NETWORK_XFRM
-	struct list_head xfrm_policy_alloc_security;
-	struct list_head xfrm_policy_clone_security;
-	struct list_head xfrm_policy_free_security;
-	struct list_head xfrm_policy_delete_security;
-	struct list_head xfrm_state_alloc;
-	struct list_head xfrm_state_alloc_acquire;
-	struct list_head xfrm_state_free_security;
-	struct list_head xfrm_state_delete_security;
-	struct list_head xfrm_policy_lookup;
-	struct list_head xfrm_state_pol_flow_match;
-	struct list_head xfrm_decode_session;
+	struct hlist_head xfrm_policy_alloc_security;
+	struct hlist_head xfrm_policy_clone_security;
+	struct hlist_head xfrm_policy_free_security;
+	struct hlist_head xfrm_policy_delete_security;
+	struct hlist_head xfrm_state_alloc;
+	struct hlist_head xfrm_state_alloc_acquire;
+	struct hlist_head xfrm_state_free_security;
+	struct hlist_head xfrm_state_delete_security;
+	struct hlist_head xfrm_policy_lookup;
+	struct hlist_head xfrm_state_pol_flow_match;
+	struct hlist_head xfrm_decode_session;
 #endif	/* CONFIG_SECURITY_NETWORK_XFRM */
 #ifdef CONFIG_KEYS
-	struct list_head key_alloc;
-	struct list_head key_free;
-	struct list_head key_permission;
-	struct list_head key_getsecurity;
+	struct hlist_head key_alloc;
+	struct hlist_head key_free;
+	struct hlist_head key_permission;
+	struct hlist_head key_getsecurity;
 #endif	/* CONFIG_KEYS */
 #ifdef CONFIG_AUDIT
-	struct list_head audit_rule_init;
-	struct list_head audit_rule_known;
-	struct list_head audit_rule_match;
-	struct list_head audit_rule_free;
+	struct hlist_head audit_rule_init;
+	struct hlist_head audit_rule_known;
+	struct hlist_head audit_rule_match;
+	struct hlist_head audit_rule_free;
 #endif /* CONFIG_AUDIT */
 #ifdef CONFIG_BPF_SYSCALL
-	struct list_head bpf;
-	struct list_head bpf_map;
-	struct list_head bpf_prog;
-	struct list_head bpf_map_alloc_security;
-	struct list_head bpf_map_free_security;
-	struct list_head bpf_prog_alloc_security;
-	struct list_head bpf_prog_free_security;
+	struct hlist_head bpf;
+	struct hlist_head bpf_map;
+	struct hlist_head bpf_prog;
+	struct hlist_head bpf_map_alloc_security;
+	struct hlist_head bpf_map_free_security;
+	struct hlist_head bpf_prog_alloc_security;
+	struct hlist_head bpf_prog_free_security;
 #endif /* CONFIG_BPF_SYSCALL */
 } __randomize_layout;
 
@@ -1998,8 +1999,8 @@ struct security_hook_heads {
  * For use with generic list macros for common operations.
  */
 struct security_hook_list {
-	struct list_head		list;
-	struct list_head		*head;
+	struct hlist_node		list;
+	struct hlist_head		*head;
 	union security_list_options	hook;
 	char				*lsm;
 } __randomize_layout;
@@ -2038,7 +2039,7 @@ static inline void security_delete_hooks(struct security_hook_list *hooks,
 	int i;
 
 	for (i = 0; i < count; i++)
-		list_del_rcu(&hooks[i].list);
+		hlist_del_rcu(&hooks[i].list);
 }
 #endif /* CONFIG_SECURITY_SELINUX_DISABLE */
 
diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h
index 23b4f9cb82db..a7ce74c74e49 100644
--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h
@@ -319,7 +319,7 @@ extern int force_sig_info(int, struct siginfo *, struct task_struct *);
 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
 extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
-				const struct cred *, u32);
+				const struct cred *);
 extern int kill_pgrp(struct pid *pid, int sig, int priv);
 extern int kill_pid(struct pid *pid, int sig, int priv);
 extern __must_check bool do_notify_parent(struct task_struct *, int);
diff --git a/include/linux/security.h b/include/linux/security.h
index 17ffd1ef6074..4a573c3be93d 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -345,7 +345,7 @@ int security_task_setscheduler(struct task_struct *p);
 int security_task_getscheduler(struct task_struct *p);
 int security_task_movememory(struct task_struct *p);
 int security_task_kill(struct task_struct *p, struct siginfo *info,
-			int sig, u32 secid);
+			int sig, const struct cred *cred);
 int security_task_prctl(int option, unsigned long arg2, unsigned long arg3,
 			unsigned long arg4, unsigned long arg5);
 void security_task_to_inode(struct task_struct *p, struct inode *inode);
@@ -1008,7 +1008,7 @@ static inline int security_task_movememory(struct task_struct *p)
 
 static inline int security_task_kill(struct task_struct *p,
 				     struct siginfo *info, int sig,
-				     u32 secid)
+				     const struct cred *cred)
 {
 	return 0;
 }