1 // SPDX-License-Identifier: GPL-2.0 2 3 /* 4 * Copyright 2020 Google LLC. 5 */ 6 7 #include "bpf_misc.h" 8 #include "vmlinux.h" 9 #include <bpf/bpf_helpers.h> 10 #include <bpf/bpf_tracing.h> 11 #include <errno.h> 12 13 struct { 14 __uint(type, BPF_MAP_TYPE_ARRAY); 15 __uint(max_entries, 1); 16 __type(key, __u32); 17 __type(value, __u64); 18 } array SEC(".maps"); 19 20 struct { 21 __uint(type, BPF_MAP_TYPE_HASH); 22 __uint(max_entries, 1); 23 __type(key, __u32); 24 __type(value, __u64); 25 } hash SEC(".maps"); 26 27 struct { 28 __uint(type, BPF_MAP_TYPE_LRU_HASH); 29 __uint(max_entries, 1); 30 __type(key, __u32); 31 __type(value, __u64); 32 } lru_hash SEC(".maps"); 33 34 struct { 35 __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); 36 __uint(max_entries, 1); 37 __type(key, __u32); 38 __type(value, __u64); 39 } percpu_array SEC(".maps"); 40 41 struct { 42 __uint(type, BPF_MAP_TYPE_PERCPU_HASH); 43 __uint(max_entries, 1); 44 __type(key, __u32); 45 __type(value, __u64); 46 } percpu_hash SEC(".maps"); 47 48 struct { 49 __uint(type, BPF_MAP_TYPE_LRU_PERCPU_HASH); 50 __uint(max_entries, 1); 51 __type(key, __u32); 52 __type(value, __u64); 53 } lru_percpu_hash SEC(".maps"); 54 55 struct inner_map { 56 __uint(type, BPF_MAP_TYPE_ARRAY); 57 __uint(max_entries, 1); 58 __type(key, int); 59 __type(value, __u64); 60 } inner_map SEC(".maps"); 61 62 struct outer_arr { 63 __uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS); 64 __uint(max_entries, 1); 65 __uint(key_size, sizeof(int)); 66 __uint(value_size, sizeof(int)); 67 __array(values, struct inner_map); 68 } outer_arr SEC(".maps") = { 69 .values = { [0] = &inner_map }, 70 }; 71 72 struct outer_hash { 73 __uint(type, BPF_MAP_TYPE_HASH_OF_MAPS); 74 __uint(max_entries, 1); 75 __uint(key_size, sizeof(int)); 76 __array(values, struct inner_map); 77 } outer_hash SEC(".maps") = { 78 .values = { [0] = &inner_map }, 79 }; 80 81 char _license[] SEC("license") = "GPL"; 82 83 int monitored_pid = 0; 84 int mprotect_count = 0; 85 int bprm_count = 0; 86 87 SEC("lsm/file_mprotect") 88 int BPF_PROG(test_int_hook, struct vm_area_struct *vma, 89 unsigned long reqprot, unsigned long prot, int ret) 90 { 91 if (ret != 0) 92 return ret; 93 94 __u32 pid = bpf_get_current_pid_tgid() >> 32; 95 int is_stack = 0; 96 97 is_stack = (vma->vm_start <= vma->vm_mm->start_stack && 98 vma->vm_end >= vma->vm_mm->start_stack); 99 100 if (is_stack && monitored_pid == pid) { 101 mprotect_count++; 102 ret = -EPERM; 103 } 104 105 return ret; 106 } 107 108 SEC("lsm.s/bprm_committed_creds") 109 int BPF_PROG(test_void_hook, struct linux_binprm *bprm) 110 { 111 __u32 pid = bpf_get_current_pid_tgid() >> 32; 112 struct inner_map *inner_map; 113 char args[64]; 114 __u32 key = 0; 115 __u64 *value; 116 117 if (monitored_pid == pid) 118 bprm_count++; 119 120 bpf_copy_from_user(args, sizeof(args), (void *)bprm->vma->vm_mm->arg_start); 121 bpf_copy_from_user(args, sizeof(args), (void *)bprm->mm->arg_start); 122 123 value = bpf_map_lookup_elem(&array, &key); 124 if (value) 125 *value = 0; 126 value = bpf_map_lookup_elem(&hash, &key); 127 if (value) 128 *value = 0; 129 value = bpf_map_lookup_elem(&lru_hash, &key); 130 if (value) 131 *value = 0; 132 value = bpf_map_lookup_elem(&percpu_array, &key); 133 if (value) 134 *value = 0; 135 value = bpf_map_lookup_elem(&percpu_hash, &key); 136 if (value) 137 *value = 0; 138 value = bpf_map_lookup_elem(&lru_percpu_hash, &key); 139 if (value) 140 *value = 0; 141 inner_map = bpf_map_lookup_elem(&outer_arr, &key); 142 if (inner_map) { 143 value = bpf_map_lookup_elem(inner_map, &key); 144 if (value) 145 *value = 0; 146 } 147 inner_map = bpf_map_lookup_elem(&outer_hash, &key); 148 if (inner_map) { 149 value = bpf_map_lookup_elem(inner_map, &key); 150 if (value) 151 *value = 0; 152 } 153 154 return 0; 155 } 156 SEC("lsm/task_free") /* lsm/ is ok, lsm.s/ fails */ 157 int BPF_PROG(test_task_free, struct task_struct *task) 158 { 159 return 0; 160 } 161 162 int copy_test = 0; 163 164 SEC("fentry.s/" SYS_PREFIX "sys_setdomainname") 165 int BPF_PROG(test_sys_setdomainname, struct pt_regs *regs) 166 { 167 void *ptr = (void *)PT_REGS_PARM1(regs); 168 int len = PT_REGS_PARM2(regs); 169 int buf = 0; 170 long ret; 171 172 ret = bpf_copy_from_user(&buf, sizeof(buf), ptr); 173 if (len == -2 && ret == 0 && buf == 1234) 174 copy_test++; 175 if (len == -3 && ret == -EFAULT) 176 copy_test++; 177 if (len == -4 && ret == -EFAULT) 178 copy_test++; 179 return 0; 180 } 181