// SPDX-License-Identifier: GPL-2.0-only/* *  Copyright (C) 2007 IBM Corporation * *  Author: Cedric Le Goater <clg@fr.ibm.com> */ #include <linux/nsproxy.h>#include <linux/ipc_namespace.h>#include <linux/sysctl.h> #include <linux/stat.h>#include <linux/capability.h>#include <linux/slab.h>#include <linux/cred.h> static int msg_max_limit_min = MIN_MSGMAX;static int msg_max_limit_max = HARD_MSGMAX; static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;static int msg_maxsize_limit_max = HARD_MSGSIZEMAX; static const struct ctl_table mq_sysctls[] = {	{		.procname	= "queues_max",		.data		= &init_ipc_ns.mq_queues_max,		.maxlen		= sizeof(int),		.mode		= 0644,		.proc_handler	= proc_dointvec,	},	{		.procname	= "msg_max",		.data		= &init_ipc_ns.mq_msg_max,		.maxlen		= sizeof(int),		.mode		= 0644,		.proc_handler	= proc_dointvec_minmax,		.extra1		= &msg_max_limit_min,		.extra2		= &msg_max_limit_max,	},	{		.procname	= "msgsize_max",		.data		= &init_ipc_ns.mq_msgsize_max,		.maxlen		= sizeof(int),		.mode		= 0644,		.proc_handler	= proc_dointvec_minmax,		.extra1		= &msg_maxsize_limit_min,		.extra2		= &msg_maxsize_limit_max,	},	{		.procname	= "msg_default",		.data		= &init_ipc_ns.mq_msg_default,		.maxlen		= sizeof(int),		.mode		= 0644,		.proc_handler	= proc_dointvec_minmax,		.extra1		= &msg_max_limit_min,		.extra2		= &msg_max_limit_max,	},	{		.procname	= "msgsize_default",		.data		= &init_ipc_ns.mq_msgsize_default,		.maxlen		= sizeof(int),		.mode		= 0644,		.proc_handler	= proc_dointvec_minmax,		.extra1		= &msg_maxsize_limit_min,		.extra2		= &msg_maxsize_limit_max,	},}; static struct ctl_table_set *set_lookup(struct ctl_table_root *root){	return &current->nsproxy->ipc_ns->mq_set;} static int set_is_seen(struct ctl_table_set *set){	return &current->nsproxy->ipc_ns->mq_set == set;} static void mq_set_ownership(struct ctl_table_header *head,			     kuid_t *uid, kgid_t *gid){	struct ipc_namespace *ns =		container_of(head->set, struct ipc_namespace, mq_set); 	kuid_t ns_root_uid = make_kuid(ns->user_ns, 0);	kgid_t ns_root_gid = make_kgid(ns->user_ns, 0); 	*uid = uid_valid(ns_root_uid) ? ns_root_uid : GLOBAL_ROOT_UID;	*gid = gid_valid(ns_root_gid) ? ns_root_gid : GLOBAL_ROOT_GID;} static int mq_permissions(struct ctl_table_header *head, const struct ctl_table *table){	int mode = table->mode;	kuid_t ns_root_uid;	kgid_t ns_root_gid; 	mq_set_ownership(head, &ns_root_uid, &ns_root_gid); 	if (uid_eq(current_euid(), ns_root_uid))		mode >>= 6; 	else if (in_egroup_p(ns_root_gid))		mode >>= 3; 	mode &= 7; 	return (mode << 6) | (mode << 3) | mode;} static struct ctl_table_root set_root = {	.lookup = set_lookup,	.permissions = mq_permissions,	.set_ownership = mq_set_ownership,}; bool setup_mq_sysctls(struct ipc_namespace *ns){	struct ctl_table *tbl; 	setup_sysctl_set(&ns->mq_set, &set_root, set_is_seen); 	tbl = kmemdup(mq_sysctls, sizeof(mq_sysctls), GFP_KERNEL);	if (tbl) {		int i; 		for (i = 0; i < ARRAY_SIZE(mq_sysctls); i++) {			if (tbl[i].data == &init_ipc_ns.mq_queues_max)				tbl[i].data = &ns->mq_queues_max; 			else if (tbl[i].data == &init_ipc_ns.mq_msg_max)				tbl[i].data = &ns->mq_msg_max; 			else if (tbl[i].data == &init_ipc_ns.mq_msgsize_max)				tbl[i].data = &ns->mq_msgsize_max; 			else if (tbl[i].data == &init_ipc_ns.mq_msg_default)				tbl[i].data = &ns->mq_msg_default; 			else if (tbl[i].data == &init_ipc_ns.mq_msgsize_default)				tbl[i].data = &ns->mq_msgsize_default;			else				tbl[i].data = NULL;		} 		ns->mq_sysctls = __register_sysctl_table(&ns->mq_set,							 "fs/mqueue", tbl,							 ARRAY_SIZE(mq_sysctls));	}	if (!ns->mq_sysctls) {		kfree(tbl);		retire_sysctl_set(&ns->mq_set);		return false;	} 	return true;} void retire_mq_sysctls(struct ipc_namespace *ns){	const struct ctl_table *tbl; 	tbl = ns->mq_sysctls->ctl_table_arg;	unregister_sysctl_table(ns->mq_sysctls);	retire_sysctl_set(&ns->mq_set);	kfree(tbl);}