Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2
3/*
4 * Copyright 2020 Google LLC.
5 */
6
7#include "vmlinux.h"
8#include <errno.h>
9#include <bpf/bpf_core_read.h>
10#include <bpf/bpf_helpers.h>
11#include <bpf/bpf_tracing.h>
12#include "bpf_misc.h"
13
14struct {
15 __uint(type, BPF_MAP_TYPE_ARRAY);
16 __uint(max_entries, 1);
17 __type(key, __u32);
18 __type(value, __u64);
19} array SEC(".maps");
20
21struct {
22 __uint(type, BPF_MAP_TYPE_HASH);
23 __uint(max_entries, 1);
24 __type(key, __u32);
25 __type(value, __u64);
26} hash SEC(".maps");
27
28struct {
29 __uint(type, BPF_MAP_TYPE_LRU_HASH);
30 __uint(max_entries, 1);
31 __type(key, __u32);
32 __type(value, __u64);
33} lru_hash SEC(".maps");
34
35struct {
36 __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
37 __uint(max_entries, 1);
38 __type(key, __u32);
39 __type(value, __u64);
40} percpu_array SEC(".maps");
41
42struct {
43 __uint(type, BPF_MAP_TYPE_PERCPU_HASH);
44 __uint(max_entries, 1);
45 __type(key, __u32);
46 __type(value, __u64);
47} percpu_hash SEC(".maps");
48
49struct {
50 __uint(type, BPF_MAP_TYPE_LRU_PERCPU_HASH);
51 __uint(max_entries, 1);
52 __type(key, __u32);
53 __type(value, __u64);
54} lru_percpu_hash SEC(".maps");
55
56struct inner_map {
57 __uint(type, BPF_MAP_TYPE_ARRAY);
58 __uint(max_entries, 1);
59 __type(key, int);
60 __type(value, __u64);
61} inner_map SEC(".maps");
62
63struct outer_arr {
64 __uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
65 __uint(max_entries, 1);
66 __uint(key_size, sizeof(int));
67 __uint(value_size, sizeof(int));
68 __array(values, struct inner_map);
69} outer_arr SEC(".maps") = {
70 .values = { [0] = &inner_map },
71};
72
73struct outer_hash {
74 __uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
75 __uint(max_entries, 1);
76 __uint(key_size, sizeof(int));
77 __array(values, struct inner_map);
78} outer_hash SEC(".maps") = {
79 .values = { [0] = &inner_map },
80};
81
82char _license[] SEC("license") = "GPL";
83
84int monitored_pid = 0;
85int mprotect_count = 0;
86int bprm_count = 0;
87
88SEC("lsm/file_mprotect")
89int BPF_PROG(test_int_hook, struct vm_area_struct *vma,
90 unsigned long reqprot, unsigned long prot, int ret)
91{
92 struct mm_struct *mm = vma->vm_mm;
93
94 if (ret != 0 || !mm)
95 return ret;
96
97 __s32 pid = bpf_get_current_pid_tgid() >> 32;
98 int is_stack = 0;
99
100 is_stack = (vma->vm_start <= mm->start_stack &&
101 vma->vm_end >= mm->start_stack);
102
103 if (is_stack && monitored_pid == pid) {
104 mprotect_count++;
105 ret = -EPERM;
106 }
107
108 return ret;
109}
110
111SEC("lsm.s/bprm_committed_creds")
112int BPF_PROG(test_void_hook, struct linux_binprm *bprm)
113{
114 __u32 pid = bpf_get_current_pid_tgid() >> 32;
115 struct inner_map *inner_map;
116 char args[64];
117 __u32 key = 0;
118 __u64 *value;
119
120 if (monitored_pid == pid)
121 bprm_count++;
122
123 bpf_copy_from_user(args, sizeof(args), (void *)bprm->vma->vm_mm->arg_start);
124 bpf_copy_from_user(args, sizeof(args), (void *)bprm->mm->arg_start);
125
126 value = bpf_map_lookup_elem(&array, &key);
127 if (value)
128 *value = 0;
129 value = bpf_map_lookup_elem(&hash, &key);
130 if (value)
131 *value = 0;
132 value = bpf_map_lookup_elem(&lru_hash, &key);
133 if (value)
134 *value = 0;
135 value = bpf_map_lookup_elem(&percpu_array, &key);
136 if (value)
137 *value = 0;
138 value = bpf_map_lookup_elem(&percpu_hash, &key);
139 if (value)
140 *value = 0;
141 value = bpf_map_lookup_elem(&lru_percpu_hash, &key);
142 if (value)
143 *value = 0;
144 inner_map = bpf_map_lookup_elem(&outer_arr, &key);
145 if (inner_map) {
146 value = bpf_map_lookup_elem(inner_map, &key);
147 if (value)
148 *value = 0;
149 }
150 inner_map = bpf_map_lookup_elem(&outer_hash, &key);
151 if (inner_map) {
152 value = bpf_map_lookup_elem(inner_map, &key);
153 if (value)
154 *value = 0;
155 }
156
157 return 0;
158}
159SEC("lsm/task_free") /* lsm/ is ok, lsm.s/ fails */
160int BPF_PROG(test_task_free, struct task_struct *task)
161{
162 return 0;
163}
164
165int copy_test = 0;
166
167SEC("fentry.s/" SYS_PREFIX "sys_setdomainname")
168int BPF_PROG(test_sys_setdomainname, struct pt_regs *regs)
169{
170 void *ptr = (void *)PT_REGS_PARM1_SYSCALL(regs);
171 int len = PT_REGS_PARM2_SYSCALL(regs);
172 int buf = 0;
173 long ret;
174
175 ret = bpf_copy_from_user(&buf, sizeof(buf), ptr);
176 if (len == -2 && ret == 0 && buf == 1234)
177 copy_test++;
178 if (len == -3 && ret == -EFAULT)
179 copy_test++;
180 if (len == -4 && ret == -EFAULT)
181 copy_test++;
182 return 0;
183}