diff options
Diffstat (limited to '')
| -rw-r--r-- | kernel/pid_sysctl.h | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/kernel/pid_sysctl.h b/kernel/pid_sysctl.h new file mode 100644 index 0000000000..2ee41a3a1d --- /dev/null +++ b/kernel/pid_sysctl.h @@ -0,0 +1,54 @@ +/* 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 */ |