/* SPDX-License-Identifier: GPL-2.0 */ #ifndef LINUX_PID_SYSCTL_H #define LINUX_PID_SYSCTL_H #include <linux/pid_namespace.h> #if defined(CONFIG_SYSCTL) && defined(CONFIG_MEMFD_CREATE) static int pid_mfd_noexec_dointvec_minmax(struct ctl_table *table, int write, void *buf, size_t *lenp, loff_t *ppos) { struct pid_namespace *ns = task_active_pid_ns(current); struct ctl_table table_copy; int err, scope, parent_scope; if (write && !ns_capable(ns->user_ns, CAP_SYS_ADMIN)) return -EPERM; table_copy = *table; /* You cannot set a lower enforcement value than your parent. */ parent_scope = pidns_memfd_noexec_scope(ns->parent); /* Equivalent to pidns_memfd_noexec_scope(ns). */ scope = max(READ_ONCE(ns->memfd_noexec_scope), parent_scope); table_copy.data = &scope; table_copy.extra1 = &parent_scope; err = proc_dointvec_minmax(&table_copy, write, buf, lenp, ppos); if (!err && write) WRITE_ONCE(ns->memfd_noexec_scope, scope); return err; } static struct ctl_table pid_ns_ctl_table_vm[] = { { .procname = "memfd_noexec", .data = &init_pid_ns.memfd_noexec_scope, .maxlen = sizeof(init_pid_ns.memfd_noexec_scope), .mode = 0644, .proc_handler = pid_mfd_noexec_dointvec_minmax, .extra1 = SYSCTL_ZERO, .extra2 = SYSCTL_TWO, }, }; static inline void register_pid_ns_sysctl_table_vm(void) { register_sysctl("vm", pid_ns_ctl_table_vm); } #else static inline void register_pid_ns_sysctl_table_vm(void) {} #endif #endif /* LINUX_PID_SYSCTL_H */