Commit | Line | Data |
---|---|---|
105ff533 JX |
1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef LINUX_PID_SYSCTL_H | |
3 | #define LINUX_PID_SYSCTL_H | |
4 | ||
5 | #include <linux/pid_namespace.h> | |
6 | ||
7 | #if defined(CONFIG_SYSCTL) && defined(CONFIG_MEMFD_CREATE) | |
105ff533 JX |
8 | static int pid_mfd_noexec_dointvec_minmax(struct ctl_table *table, |
9 | int write, void *buf, size_t *lenp, loff_t *ppos) | |
10 | { | |
11 | struct pid_namespace *ns = task_active_pid_ns(current); | |
12 | struct ctl_table table_copy; | |
9876cfe8 | 13 | int err, scope, parent_scope; |
105ff533 JX |
14 | |
15 | if (write && !ns_capable(ns->user_ns, CAP_SYS_ADMIN)) | |
16 | return -EPERM; | |
17 | ||
18 | table_copy = *table; | |
105ff533 | 19 | |
9876cfe8 AS |
20 | /* You cannot set a lower enforcement value than your parent. */ |
21 | parent_scope = pidns_memfd_noexec_scope(ns->parent); | |
22 | /* Equivalent to pidns_memfd_noexec_scope(ns). */ | |
23 | scope = max(READ_ONCE(ns->memfd_noexec_scope), parent_scope); | |
24 | ||
25 | table_copy.data = &scope; | |
26 | table_copy.extra1 = &parent_scope; | |
105ff533 | 27 | |
9876cfe8 AS |
28 | err = proc_dointvec_minmax(&table_copy, write, buf, lenp, ppos); |
29 | if (!err && write) | |
30 | WRITE_ONCE(ns->memfd_noexec_scope, scope); | |
31 | return err; | |
105ff533 JX |
32 | } |
33 | ||
34 | static struct ctl_table pid_ns_ctl_table_vm[] = { | |
35 | { | |
36 | .procname = "memfd_noexec", | |
37 | .data = &init_pid_ns.memfd_noexec_scope, | |
38 | .maxlen = sizeof(init_pid_ns.memfd_noexec_scope), | |
39 | .mode = 0644, | |
40 | .proc_handler = pid_mfd_noexec_dointvec_minmax, | |
41 | .extra1 = SYSCTL_ZERO, | |
42 | .extra2 = SYSCTL_TWO, | |
43 | }, | |
44 | { } | |
45 | }; | |
105ff533 JX |
46 | static inline void register_pid_ns_sysctl_table_vm(void) |
47 | { | |
9e7c73c0 | 48 | register_sysctl("vm", pid_ns_ctl_table_vm); |
105ff533 JX |
49 | } |
50 | #else | |
105ff533 JX |
51 | static inline void register_pid_ns_sysctl_table_vm(void) {} |
52 | #endif | |
53 | ||
54 | #endif /* LINUX_PID_SYSCTL_H */ |