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-rw-r--r--ipc/ipc_sysctl.c304
1 files changed, 304 insertions, 0 deletions
diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
new file mode 100644
index 0000000000..8c62e443f7
--- /dev/null
+++ b/ipc/ipc_sysctl.c
@@ -0,0 +1,304 @@
+// 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 "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 &current->nsproxy->ipc_ns->ipc_set;
+}
+
+static int set_is_seen(struct ctl_table_set *set)
+{
+ return &current->nsproxy->ipc_ns->ipc_set == set;
+}
+
+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 = current->nsproxy->ipc_ns;
+
+ 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;
+#endif
+ return mode;
+}
+
+static struct ctl_table_root set_root = {
+ .lookup = set_lookup,
+ .permissions = ipc_permissions,
+};
+
+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);
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