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-rw-r--r--kernel/pid_sysctl.h54
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 */