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
14 struct {
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
21 struct {
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
28 struct {
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
35 struct {
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
42 struct {
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
49 struct {
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
56 struct 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
63 struct 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
73 struct 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
82 char _license[] SEC("license") = "GPL";
83
84 int monitored_pid = 0;
85 int mprotect_count = 0;
86 int bprm_count = 0;
87
88 SEC("lsm/file_mprotect")
89 int BPF_PROG(test_int_hook, struct vm_area_struct *vma,
90 unsigned long reqprot, unsigned long prot, int ret)
91 {
92 if (ret != 0)
93 return ret;
94
95 __s32 pid = bpf_get_current_pid_tgid() >> 32;
96 int is_stack = 0;
97
98 is_stack = (vma->vm_start <= vma->vm_mm->start_stack &&
99 vma->vm_end >= vma->vm_mm->start_stack);
100
101 if (is_stack && monitored_pid == pid) {
102 mprotect_count++;
103 ret = -EPERM;
104 }
105
106 return ret;
107 }
108
109 SEC("lsm.s/bprm_committed_creds")
110 int BPF_PROG(test_void_hook, struct linux_binprm *bprm)
111 {
112 __u32 pid = bpf_get_current_pid_tgid() >> 32;
113 struct inner_map *inner_map;
114 char args[64];
115 __u32 key = 0;
116 __u64 *value;
117
118 if (monitored_pid == pid)
119 bprm_count++;
120
121 bpf_copy_from_user(args, sizeof(args), (void *)bprm->vma->vm_mm->arg_start);
122 bpf_copy_from_user(args, sizeof(args), (void *)bprm->mm->arg_start);
123
124 value = bpf_map_lookup_elem(&array, &key);
125 if (value)
126 *value = 0;
127 value = bpf_map_lookup_elem(&hash, &key);
128 if (value)
129 *value = 0;
130 value = bpf_map_lookup_elem(&lru_hash, &key);
131 if (value)
132 *value = 0;
133 value = bpf_map_lookup_elem(&percpu_array, &key);
134 if (value)
135 *value = 0;
136 value = bpf_map_lookup_elem(&percpu_hash, &key);
137 if (value)
138 *value = 0;
139 value = bpf_map_lookup_elem(&lru_percpu_hash, &key);
140 if (value)
141 *value = 0;
142 inner_map = bpf_map_lookup_elem(&outer_arr, &key);
143 if (inner_map) {
144 value = bpf_map_lookup_elem(inner_map, &key);
145 if (value)
146 *value = 0;
147 }
148 inner_map = bpf_map_lookup_elem(&outer_hash, &key);
149 if (inner_map) {
150 value = bpf_map_lookup_elem(inner_map, &key);
151 if (value)
152 *value = 0;
153 }
154
155 return 0;
156 }
157 SEC("lsm/task_free") /* lsm/ is ok, lsm.s/ fails */
158 int BPF_PROG(test_task_free, struct task_struct *task)
159 {
160 return 0;
161 }
162
163 int copy_test = 0;
164
165 SEC("fentry.s/" SYS_PREFIX "sys_setdomainname")
166 int BPF_PROG(test_sys_setdomainname, struct pt_regs *regs)
167 {
168 void *ptr = (void *)PT_REGS_PARM1_SYSCALL(regs);
169 int len = PT_REGS_PARM2_SYSCALL(regs);
170 int buf = 0;
171 long ret;
172
173 ret = bpf_copy_from_user(&buf, sizeof(buf), ptr);
174 if (len == -2 && ret == 0 && buf == 1234)
175 copy_test++;
176 if (len == -3 && ret == -EFAULT)
177 copy_test++;
178 if (len == -4 && ret == -EFAULT)
179 copy_test++;
180 return 0;
181 }
182
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