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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 | // SPDX-License-Identifier: GPL-2.0 #include <vmlinux.h> #include <bpf/bpf_tracing.h> #include <bpf/bpf_helpers.h> #include <bpf/bpf_core_read.h> #include "bpf_misc.h" #include "../bpf_testmod/bpf_testmod_kfunc.h" struct map_value { char buf[8]; struct prog_test_ref_kfunc __kptr_untrusted *unref_ptr; struct prog_test_ref_kfunc __kptr *ref_ptr; struct prog_test_member __kptr *ref_memb_ptr; }; struct array_map { __uint(type, BPF_MAP_TYPE_ARRAY); __type(key, int); __type(value, struct map_value); __uint(max_entries, 1); } array_map SEC(".maps"); SEC("?tc") __failure __msg("kptr access size must be BPF_DW") int size_not_bpf_dw(struct __sk_buff *ctx) { struct map_value *v; int key = 0; v = bpf_map_lookup_elem(&array_map, &key); if (!v) return 0; *(u32 *)&v->unref_ptr = 0; return 0; } SEC("?tc") __failure __msg("kptr access cannot have variable offset") int non_const_var_off(struct __sk_buff *ctx) { struct map_value *v; int key = 0, id; v = bpf_map_lookup_elem(&array_map, &key); if (!v) return 0; id = ctx->protocol; if (id < 4 || id > 12) return 0; *(u64 *)((void *)v + id) = 0; return 0; } SEC("?tc") __failure __msg("R1 doesn't have constant offset. kptr has to be") int non_const_var_off_kptr_xchg(struct __sk_buff *ctx) { struct map_value *v; int key = 0, id; v = bpf_map_lookup_elem(&array_map, &key); if (!v) return 0; id = ctx->protocol; if (id < 4 || id > 12) return 0; bpf_kptr_xchg((void *)v + id, NULL); return 0; } SEC("?tc") __failure __msg("kptr access misaligned expected=8 off=7") int misaligned_access_write(struct __sk_buff *ctx) { struct map_value *v; int key = 0; v = bpf_map_lookup_elem(&array_map, &key); if (!v) return 0; *(void **)((void *)v + 7) = NULL; return 0; } SEC("?tc") __failure __msg("kptr access misaligned expected=8 off=1") int misaligned_access_read(struct __sk_buff *ctx) { struct map_value *v; int key = 0; v = bpf_map_lookup_elem(&array_map, &key); if (!v) return 0; return *(u64 *)((void *)v + 1); } SEC("?tc") __failure __msg("variable untrusted_ptr_ access var_off=(0x0; 0x1e0)") int reject_var_off_store(struct __sk_buff *ctx) { struct prog_test_ref_kfunc *unref_ptr; struct map_value *v; int key = 0, id; v = bpf_map_lookup_elem(&array_map, &key); if (!v) return 0; unref_ptr = v->unref_ptr; if (!unref_ptr) return 0; id = ctx->protocol; if (id < 4 || id > 12) return 0; unref_ptr += id; v->unref_ptr = unref_ptr; return 0; } SEC("?tc") __failure __msg("invalid kptr access, R1 type=untrusted_ptr_prog_test_ref_kfunc") int reject_bad_type_match(struct __sk_buff *ctx) { struct prog_test_ref_kfunc *unref_ptr; struct map_value *v; int key = 0; v = bpf_map_lookup_elem(&array_map, &key); if (!v) return 0; unref_ptr = v->unref_ptr; if (!unref_ptr) return 0; unref_ptr = (void *)unref_ptr + 4; v->unref_ptr = unref_ptr; return 0; } SEC("?tc") __failure __msg("R1 type=untrusted_ptr_or_null_ expected=percpu_ptr_") int marked_as_untrusted_or_null(struct __sk_buff *ctx) { struct map_value *v; int key = 0; v = bpf_map_lookup_elem(&array_map, &key); if (!v) return 0; bpf_this_cpu_ptr(v->unref_ptr); return 0; } SEC("?tc") __failure __msg("access beyond struct prog_test_ref_kfunc at off 32 size 4") int correct_btf_id_check_size(struct __sk_buff *ctx) { struct prog_test_ref_kfunc *p; struct map_value *v; int key = 0; v = bpf_map_lookup_elem(&array_map, &key); if (!v) return 0; p = v->unref_ptr; if (!p) return 0; return *(int *)((void *)p + bpf_core_type_size(struct prog_test_ref_kfunc)); } SEC("?tc") __failure __msg("R1 type=untrusted_ptr_ expected=percpu_ptr_") int inherit_untrusted_on_walk(struct __sk_buff *ctx) { struct prog_test_ref_kfunc *unref_ptr; struct map_value *v; int key = 0; v = bpf_map_lookup_elem(&array_map, &key); if (!v) return 0; unref_ptr = v->unref_ptr; if (!unref_ptr) return 0; unref_ptr = unref_ptr->next; bpf_this_cpu_ptr(unref_ptr); return 0; } SEC("?tc") __failure __msg("off=8 kptr isn't referenced kptr") int reject_kptr_xchg_on_unref(struct __sk_buff *ctx) { struct map_value *v; int key = 0; v = bpf_map_lookup_elem(&array_map, &key); if (!v) return 0; bpf_kptr_xchg(&v->unref_ptr, NULL); return 0; } SEC("?tc") __failure __msg("R1 type=rcu_ptr_or_null_ expected=percpu_ptr_") int mark_ref_as_untrusted_or_null(struct __sk_buff *ctx) { struct map_value *v; int key = 0; v = bpf_map_lookup_elem(&array_map, &key); if (!v) return 0; bpf_this_cpu_ptr(v->ref_ptr); return 0; } SEC("?tc") __failure __msg("store to referenced kptr disallowed") int reject_untrusted_store_to_ref(struct __sk_buff *ctx) { struct prog_test_ref_kfunc *p; struct map_value *v; int key = 0; v = bpf_map_lookup_elem(&array_map, &key); if (!v) return 0; p = v->ref_ptr; if (!p) return 0; /* Checkmate, clang */ *(struct prog_test_ref_kfunc * volatile *)&v->ref_ptr = p; return 0; } SEC("?tc") __failure __msg("R2 must be referenced") int reject_untrusted_xchg(struct __sk_buff *ctx) { struct prog_test_ref_kfunc *p; struct map_value *v; int key = 0; v = bpf_map_lookup_elem(&array_map, &key); if (!v) return 0; p = v->ref_ptr; if (!p) return 0; bpf_kptr_xchg(&v->ref_ptr, p); return 0; } SEC("?tc") __failure __msg("invalid kptr access, R2 type=ptr_prog_test_ref_kfunc expected=ptr_prog_test_member") int reject_bad_type_xchg(struct __sk_buff *ctx) { struct prog_test_ref_kfunc *ref_ptr; struct map_value *v; int key = 0; v = bpf_map_lookup_elem(&array_map, &key); if (!v) return 0; ref_ptr = bpf_kfunc_call_test_acquire(&(unsigned long){0}); if (!ref_ptr) return 0; bpf_kptr_xchg(&v->ref_memb_ptr, ref_ptr); return 0; } SEC("?tc") __failure __msg("invalid kptr access, R2 type=ptr_prog_test_ref_kfunc") int reject_member_of_ref_xchg(struct __sk_buff *ctx) { struct prog_test_ref_kfunc *ref_ptr; struct map_value *v; int key = 0; v = bpf_map_lookup_elem(&array_map, &key); if (!v) return 0; ref_ptr = bpf_kfunc_call_test_acquire(&(unsigned long){0}); if (!ref_ptr) return 0; bpf_kptr_xchg(&v->ref_memb_ptr, &ref_ptr->memb); return 0; } SEC("?syscall") __failure __msg("kptr cannot be accessed indirectly by helper") int reject_indirect_helper_access(struct __sk_buff *ctx) { struct map_value *v; int key = 0; v = bpf_map_lookup_elem(&array_map, &key); if (!v) return 0; bpf_get_current_comm(v, sizeof(v->buf) + 1); return 0; } __noinline int write_func(int *p) { return p ? *p = 42 : 0; } SEC("?tc") __failure __msg("kptr cannot be accessed indirectly by helper") int reject_indirect_global_func_access(struct __sk_buff *ctx) { struct map_value *v; int key = 0; v = bpf_map_lookup_elem(&array_map, &key); if (!v) return 0; return write_func((void *)v + 5); } SEC("?tc") __failure __msg("Unreleased reference id=5 alloc_insn=") int kptr_xchg_ref_state(struct __sk_buff *ctx) { struct prog_test_ref_kfunc *p; struct map_value *v; int key = 0; v = bpf_map_lookup_elem(&array_map, &key); if (!v) return 0; p = bpf_kfunc_call_test_acquire(&(unsigned long){0}); if (!p) return 0; bpf_kptr_xchg(&v->ref_ptr, p); return 0; } SEC("?tc") __failure __msg("Possibly NULL pointer passed to helper arg2") int kptr_xchg_possibly_null(struct __sk_buff *ctx) { struct prog_test_ref_kfunc *p; struct map_value *v; int key = 0; v = bpf_map_lookup_elem(&array_map, &key); if (!v) return 0; p = bpf_kfunc_call_test_acquire(&(unsigned long){0}); /* PTR_TO_BTF_ID | PTR_MAYBE_NULL passed to bpf_kptr_xchg() */ p = bpf_kptr_xchg(&v->ref_ptr, p); if (p) bpf_kfunc_call_test_release(p); return 0; } char _license[] SEC("license") = "GPL"; |