| 1 |
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| 2 | #ifndef LINUX_PID_SYSCTL_H
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| 3 | #define LINUX_PID_SYSCTL_H
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| 4 |
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| 5 | #include <linux/pid_namespace.h>
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| 6 |
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| 7 | #if defined(CONFIG_SYSCTL) && defined(CONFIG_MEMFD_CREATE)
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| 8 | static int pid_mfd_noexec_dointvec_minmax(const struct ctl_table *table,
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| 9 | int write, void *buf, size_t *lenp, loff_t *ppos)
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| 10 | {
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| 11 | struct pid_namespace *ns = task_active_pid_ns(current);
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| 12 | struct ctl_table table_copy;
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| 13 | int err, scope, parent_scope;
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| 14 |
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| 15 | if (write && !ns_capable(ns->user_ns, CAP_SYS_ADMIN))
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| 16 | return -EPERM;
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| 17 |
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| 18 | table_copy = *table;
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| 19 |
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| 20 |
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| 21 | parent_scope = pidns_memfd_noexec_scope(ns->parent);
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| 22 |
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| 23 | scope = max(READ_ONCE(ns->memfd_noexec_scope), parent_scope);
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| 24 |
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| 25 | table_copy.data = &scope;
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| 26 | table_copy.extra1 = &parent_scope;
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| 27 |
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| 28 | err = proc_dointvec_minmax(&table_copy, write, buf, lenp, ppos);
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| 29 | if (!err && write)
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| 30 | WRITE_ONCE(ns->memfd_noexec_scope, scope);
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| 31 | return err;
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| 32 | }
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| 33 |
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| 34 | static const struct ctl_table pid_ns_ctl_table_vm[] = {
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| 35 | {
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| 36 | .procname = "memfd_noexec",
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| 37 | .data = &init_pid_ns.memfd_noexec_scope,
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| 38 | .maxlen = sizeof(init_pid_ns.memfd_noexec_scope),
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| 39 | .mode = 0644,
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| 40 | .proc_handler = pid_mfd_noexec_dointvec_minmax,
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| 41 | .extra1 = SYSCTL_ZERO,
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| 42 | .extra2 = SYSCTL_TWO,
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| 43 | },
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| 44 | };
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| 45 | static inline void register_pid_ns_sysctl_table_vm(void)
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| 46 | {
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| 47 | register_sysctl("vm", pid_ns_ctl_table_vm);
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| 48 | }
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| 49 | #else
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| 50 | static inline void register_pid_ns_sysctl_table_vm(void) {}
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| 51 | #endif
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| 52 |
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| 53 | #endif
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