| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Copyright (C) 2007 |
| * |
| * Author: Eric Biederman <ebiederm@xmision.com> |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/ipc.h> |
| #include <linux/nsproxy.h> |
| #include <linux/sysctl.h> |
| #include <linux/uaccess.h> |
| #include <linux/capability.h> |
| #include <linux/ipc_namespace.h> |
| #include <linux/msg.h> |
| #include <linux/slab.h> |
| #include <linux/cred.h> |
| #include "util.h" |
| |
| static int proc_ipc_dointvec_minmax_orphans(struct ctl_table *table, int write, |
| void *buffer, size_t *lenp, loff_t *ppos) |
| { |
| struct ipc_namespace *ns = |
| container_of(table->data, struct ipc_namespace, shm_rmid_forced); |
| int err; |
| |
| err = proc_dointvec_minmax(table, write, buffer, lenp, ppos); |
| |
| if (err < 0) |
| return err; |
| if (ns->shm_rmid_forced) |
| shm_destroy_orphaned(ns); |
| return err; |
| } |
| |
| static int proc_ipc_auto_msgmni(struct ctl_table *table, int write, |
| void *buffer, size_t *lenp, loff_t *ppos) |
| { |
| struct ctl_table ipc_table; |
| int dummy = 0; |
| |
| memcpy(&ipc_table, table, sizeof(ipc_table)); |
| ipc_table.data = &dummy; |
| |
| if (write) |
| pr_info_once("writing to auto_msgmni has no effect"); |
| |
| return proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos); |
| } |
| |
| static int proc_ipc_sem_dointvec(struct ctl_table *table, int write, |
| void *buffer, size_t *lenp, loff_t *ppos) |
| { |
| struct ipc_namespace *ns = |
| container_of(table->data, struct ipc_namespace, sem_ctls); |
| int ret, semmni; |
| |
| semmni = ns->sem_ctls[3]; |
| ret = proc_dointvec(table, write, buffer, lenp, ppos); |
| |
| if (!ret) |
| ret = sem_check_semmni(ns); |
| |
| /* |
| * Reset the semmni value if an error happens. |
| */ |
| if (ret) |
| ns->sem_ctls[3] = semmni; |
| return ret; |
| } |
| |
| int ipc_mni = IPCMNI; |
| int ipc_mni_shift = IPCMNI_SHIFT; |
| int ipc_min_cycle = RADIX_TREE_MAP_SIZE; |
| |
| static struct ctl_table ipc_sysctls[] = { |
| { |
| .procname = "shmmax", |
| .data = &init_ipc_ns.shm_ctlmax, |
| .maxlen = sizeof(init_ipc_ns.shm_ctlmax), |
| .mode = 0644, |
| .proc_handler = proc_doulongvec_minmax, |
| }, |
| { |
| .procname = "shmall", |
| .data = &init_ipc_ns.shm_ctlall, |
| .maxlen = sizeof(init_ipc_ns.shm_ctlall), |
| .mode = 0644, |
| .proc_handler = proc_doulongvec_minmax, |
| }, |
| { |
| .procname = "shmmni", |
| .data = &init_ipc_ns.shm_ctlmni, |
| .maxlen = sizeof(init_ipc_ns.shm_ctlmni), |
| .mode = 0644, |
| .proc_handler = proc_dointvec_minmax, |
| .extra1 = SYSCTL_ZERO, |
| .extra2 = &ipc_mni, |
| }, |
| { |
| .procname = "shm_rmid_forced", |
| .data = &init_ipc_ns.shm_rmid_forced, |
| .maxlen = sizeof(init_ipc_ns.shm_rmid_forced), |
| .mode = 0644, |
| .proc_handler = proc_ipc_dointvec_minmax_orphans, |
| .extra1 = SYSCTL_ZERO, |
| .extra2 = SYSCTL_ONE, |
| }, |
| { |
| .procname = "msgmax", |
| .data = &init_ipc_ns.msg_ctlmax, |
| .maxlen = sizeof(init_ipc_ns.msg_ctlmax), |
| .mode = 0644, |
| .proc_handler = proc_dointvec_minmax, |
| .extra1 = SYSCTL_ZERO, |
| .extra2 = SYSCTL_INT_MAX, |
| }, |
| { |
| .procname = "msgmni", |
| .data = &init_ipc_ns.msg_ctlmni, |
| .maxlen = sizeof(init_ipc_ns.msg_ctlmni), |
| .mode = 0644, |
| .proc_handler = proc_dointvec_minmax, |
| .extra1 = SYSCTL_ZERO, |
| .extra2 = &ipc_mni, |
| }, |
| { |
| .procname = "auto_msgmni", |
| .data = NULL, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = proc_ipc_auto_msgmni, |
| .extra1 = SYSCTL_ZERO, |
| .extra2 = SYSCTL_ONE, |
| }, |
| { |
| .procname = "msgmnb", |
| .data = &init_ipc_ns.msg_ctlmnb, |
| .maxlen = sizeof(init_ipc_ns.msg_ctlmnb), |
| .mode = 0644, |
| .proc_handler = proc_dointvec_minmax, |
| .extra1 = SYSCTL_ZERO, |
| .extra2 = SYSCTL_INT_MAX, |
| }, |
| { |
| .procname = "sem", |
| .data = &init_ipc_ns.sem_ctls, |
| .maxlen = 4*sizeof(int), |
| .mode = 0644, |
| .proc_handler = proc_ipc_sem_dointvec, |
| }, |
| #ifdef CONFIG_CHECKPOINT_RESTORE |
| { |
| .procname = "sem_next_id", |
| .data = &init_ipc_ns.ids[IPC_SEM_IDS].next_id, |
| .maxlen = sizeof(init_ipc_ns.ids[IPC_SEM_IDS].next_id), |
| .mode = 0444, |
| .proc_handler = proc_dointvec_minmax, |
| .extra1 = SYSCTL_ZERO, |
| .extra2 = SYSCTL_INT_MAX, |
| }, |
| { |
| .procname = "msg_next_id", |
| .data = &init_ipc_ns.ids[IPC_MSG_IDS].next_id, |
| .maxlen = sizeof(init_ipc_ns.ids[IPC_MSG_IDS].next_id), |
| .mode = 0444, |
| .proc_handler = proc_dointvec_minmax, |
| .extra1 = SYSCTL_ZERO, |
| .extra2 = SYSCTL_INT_MAX, |
| }, |
| { |
| .procname = "shm_next_id", |
| .data = &init_ipc_ns.ids[IPC_SHM_IDS].next_id, |
| .maxlen = sizeof(init_ipc_ns.ids[IPC_SHM_IDS].next_id), |
| .mode = 0444, |
| .proc_handler = proc_dointvec_minmax, |
| .extra1 = SYSCTL_ZERO, |
| .extra2 = SYSCTL_INT_MAX, |
| }, |
| #endif |
| {} |
| }; |
| |
| static struct ctl_table_set *set_lookup(struct ctl_table_root *root) |
| { |
| return ¤t->nsproxy->ipc_ns->ipc_set; |
| } |
| |
| static int set_is_seen(struct ctl_table_set *set) |
| { |
| return ¤t->nsproxy->ipc_ns->ipc_set == set; |
| } |
| |
| static void ipc_set_ownership(struct ctl_table_header *head, |
| struct ctl_table *table, |
| kuid_t *uid, kgid_t *gid) |
| { |
| struct ipc_namespace *ns = |
| container_of(head->set, struct ipc_namespace, ipc_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 ipc_permissions(struct ctl_table_header *head, struct ctl_table *table) |
| { |
| int mode = table->mode; |
| |
| #ifdef CONFIG_CHECKPOINT_RESTORE |
| struct ipc_namespace *ns = |
| container_of(head->set, struct ipc_namespace, ipc_set); |
| |
| if (((table->data == &ns->ids[IPC_SEM_IDS].next_id) || |
| (table->data == &ns->ids[IPC_MSG_IDS].next_id) || |
| (table->data == &ns->ids[IPC_SHM_IDS].next_id)) && |
| checkpoint_restore_ns_capable(ns->user_ns)) |
| mode = 0666; |
| else |
| #endif |
| { |
| kuid_t ns_root_uid; |
| kgid_t ns_root_gid; |
| |
| ipc_set_ownership(head, table, &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 = ipc_permissions, |
| .set_ownership = ipc_set_ownership, |
| }; |
| |
| bool setup_ipc_sysctls(struct ipc_namespace *ns) |
| { |
| struct ctl_table *tbl; |
| |
| setup_sysctl_set(&ns->ipc_set, &set_root, set_is_seen); |
| |
| tbl = kmemdup(ipc_sysctls, sizeof(ipc_sysctls), GFP_KERNEL); |
| if (tbl) { |
| int i; |
| |
| for (i = 0; i < ARRAY_SIZE(ipc_sysctls); i++) { |
| if (tbl[i].data == &init_ipc_ns.shm_ctlmax) |
| tbl[i].data = &ns->shm_ctlmax; |
| |
| else if (tbl[i].data == &init_ipc_ns.shm_ctlall) |
| tbl[i].data = &ns->shm_ctlall; |
| |
| else if (tbl[i].data == &init_ipc_ns.shm_ctlmni) |
| tbl[i].data = &ns->shm_ctlmni; |
| |
| else if (tbl[i].data == &init_ipc_ns.shm_rmid_forced) |
| tbl[i].data = &ns->shm_rmid_forced; |
| |
| else if (tbl[i].data == &init_ipc_ns.msg_ctlmax) |
| tbl[i].data = &ns->msg_ctlmax; |
| |
| else if (tbl[i].data == &init_ipc_ns.msg_ctlmni) |
| tbl[i].data = &ns->msg_ctlmni; |
| |
| else if (tbl[i].data == &init_ipc_ns.msg_ctlmnb) |
| tbl[i].data = &ns->msg_ctlmnb; |
| |
| else if (tbl[i].data == &init_ipc_ns.sem_ctls) |
| tbl[i].data = &ns->sem_ctls; |
| #ifdef CONFIG_CHECKPOINT_RESTORE |
| else if (tbl[i].data == &init_ipc_ns.ids[IPC_SEM_IDS].next_id) |
| tbl[i].data = &ns->ids[IPC_SEM_IDS].next_id; |
| |
| else if (tbl[i].data == &init_ipc_ns.ids[IPC_MSG_IDS].next_id) |
| tbl[i].data = &ns->ids[IPC_MSG_IDS].next_id; |
| |
| else if (tbl[i].data == &init_ipc_ns.ids[IPC_SHM_IDS].next_id) |
| tbl[i].data = &ns->ids[IPC_SHM_IDS].next_id; |
| #endif |
| else |
| tbl[i].data = NULL; |
| } |
| |
| ns->ipc_sysctls = __register_sysctl_table(&ns->ipc_set, "kernel", tbl, |
| ARRAY_SIZE(ipc_sysctls)); |
| } |
| if (!ns->ipc_sysctls) { |
| kfree(tbl); |
| retire_sysctl_set(&ns->ipc_set); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| void retire_ipc_sysctls(struct ipc_namespace *ns) |
| { |
| struct ctl_table *tbl; |
| |
| tbl = ns->ipc_sysctls->ctl_table_arg; |
| unregister_sysctl_table(ns->ipc_sysctls); |
| retire_sysctl_set(&ns->ipc_set); |
| kfree(tbl); |
| } |
| |
| static int __init ipc_sysctl_init(void) |
| { |
| if (!setup_ipc_sysctls(&init_ipc_ns)) { |
| pr_warn("ipc sysctl registration failed\n"); |
| return -ENOMEM; |
| } |
| return 0; |
| } |
| |
| device_initcall(ipc_sysctl_init); |
| |
| static int __init ipc_mni_extend(char *str) |
| { |
| ipc_mni = IPCMNI_EXTEND; |
| ipc_mni_shift = IPCMNI_EXTEND_SHIFT; |
| ipc_min_cycle = IPCMNI_EXTEND_MIN_CYCLE; |
| pr_info("IPCMNI extended to %d.\n", ipc_mni); |
| return 0; |
| } |
| early_param("ipcmni_extend", ipc_mni_extend); |
