1 // SPDX-License-Identifier: GPL-2.0
2
3 /*
4 * Copyright 2020 Google LLC.
5 */
6
7 #include "vmlinux.h"
8 #include <bpf/bpf_helpers.h>
9 #include <bpf/bpf_tracing.h>
10 #include <errno.h>
11
12 struct {
13 __uint(type, BPF_MAP_TYPE_ARRAY);
14 __uint(max_entries, 1);
15 __type(key, __u32);
16 __type(value, __u64);
17 } array SEC(".maps");
18
19 struct {
20 __uint(type, BPF_MAP_TYPE_HASH);
21 __uint(max_entries, 1);
22 __type(key, __u32);
23 __type(value, __u64);
24 } hash SEC(".maps");
25
26 struct {
27 __uint(type, BPF_MAP_TYPE_LRU_HASH);
28 __uint(max_entries, 1);
29 __type(key, __u32);
30 __type(value, __u64);
31 } lru_hash SEC(".maps");
32
33 char _license[] SEC("license") = "GPL";
34
35 int monitored_pid = 0;
36 int mprotect_count = 0;
37 int bprm_count = 0;
38
39 SEC("lsm/file_mprotect")
BPF_PROG(test_int_hook,struct vm_area_struct * vma,unsigned long reqprot,unsigned long prot,int ret)40 int BPF_PROG(test_int_hook, struct vm_area_struct *vma,
41 unsigned long reqprot, unsigned long prot, int ret)
42 {
43 if (ret != 0)
44 return ret;
45
46 __u32 pid = bpf_get_current_pid_tgid() >> 32;
47 int is_stack = 0;
48
49 is_stack = (vma->vm_start <= vma->vm_mm->start_stack &&
50 vma->vm_end >= vma->vm_mm->start_stack);
51
52 if (is_stack && monitored_pid == pid) {
53 mprotect_count++;
54 ret = -EPERM;
55 }
56
57 return ret;
58 }
59
60 SEC("lsm.s/bprm_committed_creds")
BPF_PROG(test_void_hook,struct linux_binprm * bprm)61 int BPF_PROG(test_void_hook, struct linux_binprm *bprm)
62 {
63 __u32 pid = bpf_get_current_pid_tgid() >> 32;
64 char args[64];
65 __u32 key = 0;
66 __u64 *value;
67
68 if (monitored_pid == pid)
69 bprm_count++;
70
71 bpf_copy_from_user(args, sizeof(args), (void *)bprm->vma->vm_mm->arg_start);
72 bpf_copy_from_user(args, sizeof(args), (void *)bprm->mm->arg_start);
73
74 value = bpf_map_lookup_elem(&array, &key);
75 if (value)
76 *value = 0;
77 value = bpf_map_lookup_elem(&hash, &key);
78 if (value)
79 *value = 0;
80 value = bpf_map_lookup_elem(&lru_hash, &key);
81 if (value)
82 *value = 0;
83
84 return 0;
85 }
86 SEC("lsm/task_free") /* lsm/ is ok, lsm.s/ fails */
BPF_PROG(test_task_free,struct task_struct * task)87 int BPF_PROG(test_task_free, struct task_struct *task)
88 {
89 return 0;
90 }
91
92 int copy_test = 0;
93
94 SEC("fentry.s/__x64_sys_setdomainname")
BPF_PROG(test_sys_setdomainname,struct pt_regs * regs)95 int BPF_PROG(test_sys_setdomainname, struct pt_regs *regs)
96 {
97 void *ptr = (void *)PT_REGS_PARM1(regs);
98 int len = PT_REGS_PARM2(regs);
99 int buf = 0;
100 long ret;
101
102 ret = bpf_copy_from_user(&buf, sizeof(buf), ptr);
103 if (len == -2 && ret == 0 && buf == 1234)
104 copy_test++;
105 if (len == -3 && ret == -EFAULT)
106 copy_test++;
107 if (len == -4 && ret == -EFAULT)
108 copy_test++;
109 return 0;
110 }
111
