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alistair23-linux/samples/bpf/test_verifier.c
Alexei Starovoitov 725f9dcd58 bpf: fix two bugs in verification logic when accessing 'ctx' pointer 
1.
first bug is a silly mistake. It broke tracing examples and prevented
simple bpf programs from loading.

In the following code:
if (insn->imm == 0 && BPF_SIZE(insn->code) == BPF_W) {
} else if (...) {
  // this part should have been executed when
  // insn->code == BPF_W and insn->imm != 0
}

Obviously it's not doing that. So simple instructions like:
r2 = *(u64 *)(r1 + 8)
will be rejected. Note the comments in the code around these branches
were and still valid and indicate the true intent.

Replace it with:
if (BPF_SIZE(insn->code) != BPF_W)
  continue;

if (insn->imm == 0) {
} else if (...) {
  // now this code will be executed when
  // insn->code == BPF_W and insn->imm != 0
}

2.
second bug is more subtle.
If malicious code is using the same dest register as source register,
the checks designed to prevent the same instruction to be used with different
pointer types will fail to trigger, since we were assigning src_reg_type
when it was already overwritten by check_mem_access().
The fix is trivial. Just move line:
src_reg_type = regs[insn->src_reg].type;
before check_mem_access().
Add new 'access skb fields bad4' test to check this case.

Fixes: 9bac3d6d54 ("bpf: allow extended BPF programs access skb fields")
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-16 14:08:49 -04:00

836 lines
21 KiB
C
Raw Blame History

/*
* Testsuite for eBPF verifier
*
* Copyright (c) 2014 PLUMgrid, http://plumgrid.com
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*/
#include <stdio.h>
#include <unistd.h>
#include <linux/bpf.h>
#include <errno.h>
#include <linux/unistd.h>
#include <string.h>
#include <linux/filter.h>
#include <stddef.h>
#include "libbpf.h"
#define MAX_INSNS 512
#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
struct bpf_test {
const char *descr;
struct bpf_insn insns[MAX_INSNS];
int fixup[32];
const char *errstr;
enum {
ACCEPT,
REJECT
} result;
};
static struct bpf_test tests[] = {
{
"add+sub+mul",
.insns = {
BPF_MOV64_IMM(BPF_REG_1, 1),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 2),
BPF_MOV64_IMM(BPF_REG_2, 3),
BPF_ALU64_REG(BPF_SUB, BPF_REG_1, BPF_REG_2),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -1),
BPF_ALU64_IMM(BPF_MUL, BPF_REG_1, 3),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
},
{
"unreachable",
.insns = {
BPF_EXIT_INSN(),
BPF_EXIT_INSN(),
},
.errstr = "unreachable",
.result = REJECT,
},
{
"unreachable2",
.insns = {
BPF_JMP_IMM(BPF_JA, 0, 0, 1),
BPF_JMP_IMM(BPF_JA, 0, 0, 0),
BPF_EXIT_INSN(),
},
.errstr = "unreachable",
.result = REJECT,
},
{
"out of range jump",
.insns = {
BPF_JMP_IMM(BPF_JA, 0, 0, 1),
BPF_EXIT_INSN(),
},
.errstr = "jump out of range",
.result = REJECT,
},
{
"out of range jump2",
.insns = {
BPF_JMP_IMM(BPF_JA, 0, 0, -2),
BPF_EXIT_INSN(),
},
.errstr = "jump out of range",
.result = REJECT,
},
{
"test1 ld_imm64",
.insns = {
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1),
BPF_LD_IMM64(BPF_REG_0, 0),
BPF_LD_IMM64(BPF_REG_0, 0),
BPF_LD_IMM64(BPF_REG_0, 1),
BPF_LD_IMM64(BPF_REG_0, 1),
BPF_MOV64_IMM(BPF_REG_0, 2),
BPF_EXIT_INSN(),
},
.errstr = "invalid BPF_LD_IMM insn",
.result = REJECT,
},
{
"test2 ld_imm64",
.insns = {
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1),
BPF_LD_IMM64(BPF_REG_0, 0),
BPF_LD_IMM64(BPF_REG_0, 0),
BPF_LD_IMM64(BPF_REG_0, 1),
BPF_LD_IMM64(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.errstr = "invalid BPF_LD_IMM insn",
.result = REJECT,
},
{
"test3 ld_imm64",
.insns = {
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1),
BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, 0, 0, 0),
BPF_LD_IMM64(BPF_REG_0, 0),
BPF_LD_IMM64(BPF_REG_0, 0),
BPF_LD_IMM64(BPF_REG_0, 1),
BPF_LD_IMM64(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.errstr = "invalid bpf_ld_imm64 insn",
.result = REJECT,
},
{
"test4 ld_imm64",
.insns = {
BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, 0, 0, 0),
BPF_EXIT_INSN(),
},
.errstr = "invalid bpf_ld_imm64 insn",
.result = REJECT,
},
{
"test5 ld_imm64",
.insns = {
BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, 0, 0, 0),
},
.errstr = "invalid bpf_ld_imm64 insn",
.result = REJECT,
},
{
"no bpf_exit",
.insns = {
BPF_ALU64_REG(BPF_MOV, BPF_REG_0, BPF_REG_2),
},
.errstr = "jump out of range",
.result = REJECT,
},
{
"loop (back-edge)",
.insns = {
BPF_JMP_IMM(BPF_JA, 0, 0, -1),
BPF_EXIT_INSN(),
},
.errstr = "back-edge",
.result = REJECT,
},
{
"loop2 (back-edge)",
.insns = {
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
BPF_MOV64_REG(BPF_REG_3, BPF_REG_0),
BPF_JMP_IMM(BPF_JA, 0, 0, -4),
BPF_EXIT_INSN(),
},
.errstr = "back-edge",
.result = REJECT,
},
{
"conditional loop",
.insns = {
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
BPF_MOV64_REG(BPF_REG_3, BPF_REG_0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, -3),
BPF_EXIT_INSN(),
},
.errstr = "back-edge",
.result = REJECT,
},
{
"read uninitialized register",
.insns = {
BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
BPF_EXIT_INSN(),
},
.errstr = "R2 !read_ok",
.result = REJECT,
},
{
"read invalid register",
.insns = {
BPF_MOV64_REG(BPF_REG_0, -1),
BPF_EXIT_INSN(),
},
.errstr = "R15 is invalid",
.result = REJECT,
},
{
"program doesn't init R0 before exit",
.insns = {
BPF_ALU64_REG(BPF_MOV, BPF_REG_2, BPF_REG_1),
BPF_EXIT_INSN(),
},
.errstr = "R0 !read_ok",
.result = REJECT,
},
{
"program doesn't init R0 before exit in all branches",
.insns = {
BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 2),
BPF_EXIT_INSN(),
},
.errstr = "R0 !read_ok",
.result = REJECT,
},
{
"stack out of bounds",
.insns = {
BPF_ST_MEM(BPF_DW, BPF_REG_10, 8, 0),
BPF_EXIT_INSN(),
},
.errstr = "invalid stack",
.result = REJECT,
},
{
"invalid call insn1",
.insns = {
BPF_RAW_INSN(BPF_JMP | BPF_CALL | BPF_X, 0, 0, 0, 0),
BPF_EXIT_INSN(),
},
.errstr = "BPF_CALL uses reserved",
.result = REJECT,
},
{
"invalid call insn2",
.insns = {
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 1, 0),
BPF_EXIT_INSN(),
},
.errstr = "BPF_CALL uses reserved",
.result = REJECT,
},
{
"invalid function call",
.insns = {
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, 1234567),
BPF_EXIT_INSN(),
},
.errstr = "invalid func 1234567",
.result = REJECT,
},
{
"uninitialized stack1",
.insns = {
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
BPF_EXIT_INSN(),
},
.fixup = {2},
.errstr = "invalid indirect read from stack",
.result = REJECT,
},
{
"uninitialized stack2",
.insns = {
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_2, -8),
BPF_EXIT_INSN(),
},
.errstr = "invalid read from stack",
.result = REJECT,
},
{
"check valid spill/fill",
.insns = {
/* spill R1(ctx) into stack */
BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, -8),
/* fill it back into R2 */
BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_10, -8),
/* should be able to access R0 = *(R2 + 8) */
/* BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_2, 8), */
BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
},
{
"check corrupted spill/fill",
.insns = {
/* spill R1(ctx) into stack */
BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, -8),
/* mess up with R1 pointer on stack */
BPF_ST_MEM(BPF_B, BPF_REG_10, -7, 0x23),
/* fill back into R0 should fail */
BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
BPF_EXIT_INSN(),
},
.errstr = "corrupted spill",
.result = REJECT,
},
{
"invalid src register in STX",
.insns = {
BPF_STX_MEM(BPF_B, BPF_REG_10, -1, -1),
BPF_EXIT_INSN(),
},
.errstr = "R15 is invalid",
.result = REJECT,
},
{
"invalid dst register in STX",
.insns = {
BPF_STX_MEM(BPF_B, 14, BPF_REG_10, -1),
BPF_EXIT_INSN(),
},
.errstr = "R14 is invalid",
.result = REJECT,
},
{
"invalid dst register in ST",
.insns = {
BPF_ST_MEM(BPF_B, 14, -1, -1),
BPF_EXIT_INSN(),
},
.errstr = "R14 is invalid",
.result = REJECT,
},
{
"invalid src register in LDX",
.insns = {
BPF_LDX_MEM(BPF_B, BPF_REG_0, 12, 0),
BPF_EXIT_INSN(),
},
.errstr = "R12 is invalid",
.result = REJECT,
},
{
"invalid dst register in LDX",
.insns = {
BPF_LDX_MEM(BPF_B, 11, BPF_REG_1, 0),
BPF_EXIT_INSN(),
},
.errstr = "R11 is invalid",
.result = REJECT,
},
{
"junk insn",
.insns = {
BPF_RAW_INSN(0, 0, 0, 0, 0),
BPF_EXIT_INSN(),
},
.errstr = "invalid BPF_LD_IMM",
.result = REJECT,
},
{
"junk insn2",
.insns = {
BPF_RAW_INSN(1, 0, 0, 0, 0),
BPF_EXIT_INSN(),
},
.errstr = "BPF_LDX uses reserved fields",
.result = REJECT,
},
{
"junk insn3",
.insns = {
BPF_RAW_INSN(-1, 0, 0, 0, 0),
BPF_EXIT_INSN(),
},
.errstr = "invalid BPF_ALU opcode f0",
.result = REJECT,
},
{
"junk insn4",
.insns = {
BPF_RAW_INSN(-1, -1, -1, -1, -1),
BPF_EXIT_INSN(),
},
.errstr = "invalid BPF_ALU opcode f0",
.result = REJECT,
},
{
"junk insn5",
.insns = {
BPF_RAW_INSN(0x7f, -1, -1, -1, -1),
BPF_EXIT_INSN(),
},
.errstr = "BPF_ALU uses reserved fields",
.result = REJECT,
},
{
"misaligned read from stack",
.insns = {
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_2, -4),
BPF_EXIT_INSN(),
},
.errstr = "misaligned access",
.result = REJECT,
},
{
"invalid map_fd for function call",
.insns = {
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
BPF_ALU64_REG(BPF_MOV, BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_delete_elem),
BPF_EXIT_INSN(),
},
.errstr = "fd 0 is not pointing to valid bpf_map",
.result = REJECT,
},
{
"don't check return value before access",
.insns = {
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 0),
BPF_EXIT_INSN(),
},
.fixup = {3},
.errstr = "R0 invalid mem access 'map_value_or_null'",
.result = REJECT,
},
{
"access memory with incorrect alignment",
.insns = {
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
BPF_ST_MEM(BPF_DW, BPF_REG_0, 4, 0),
BPF_EXIT_INSN(),
},
.fixup = {3},
.errstr = "misaligned access",
.result = REJECT,
},
{
"sometimes access memory with incorrect alignment",
.insns = {
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 0),
BPF_EXIT_INSN(),
BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 1),
BPF_EXIT_INSN(),
},
.fixup = {3},
.errstr = "R0 invalid mem access",
.result = REJECT,
},
{
"jump test 1",
.insns = {
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_1, -8),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1),
BPF_ST_MEM(BPF_DW, BPF_REG_2, -8, 0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 1, 1),
BPF_ST_MEM(BPF_DW, BPF_REG_2, -16, 1),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 2, 1),
BPF_ST_MEM(BPF_DW, BPF_REG_2, -8, 2),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 3, 1),
BPF_ST_MEM(BPF_DW, BPF_REG_2, -16, 3),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 4, 1),
BPF_ST_MEM(BPF_DW, BPF_REG_2, -8, 4),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 5, 1),
BPF_ST_MEM(BPF_DW, BPF_REG_2, -32, 5),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
},
{
"jump test 2",
.insns = {
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 2),
BPF_ST_MEM(BPF_DW, BPF_REG_2, -8, 0),
BPF_JMP_IMM(BPF_JA, 0, 0, 14),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 1, 2),
BPF_ST_MEM(BPF_DW, BPF_REG_2, -16, 0),
BPF_JMP_IMM(BPF_JA, 0, 0, 11),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 2, 2),
BPF_ST_MEM(BPF_DW, BPF_REG_2, -32, 0),
BPF_JMP_IMM(BPF_JA, 0, 0, 8),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 3, 2),
BPF_ST_MEM(BPF_DW, BPF_REG_2, -40, 0),
BPF_JMP_IMM(BPF_JA, 0, 0, 5),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 4, 2),
BPF_ST_MEM(BPF_DW, BPF_REG_2, -48, 0),
BPF_JMP_IMM(BPF_JA, 0, 0, 2),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 5, 1),
BPF_ST_MEM(BPF_DW, BPF_REG_2, -56, 0),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
},
{
"jump test 3",
.insns = {
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 3),
BPF_ST_MEM(BPF_DW, BPF_REG_2, -8, 0),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_JMP_IMM(BPF_JA, 0, 0, 19),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 1, 3),
BPF_ST_MEM(BPF_DW, BPF_REG_2, -16, 0),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -16),
BPF_JMP_IMM(BPF_JA, 0, 0, 15),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 2, 3),
BPF_ST_MEM(BPF_DW, BPF_REG_2, -32, 0),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -32),
BPF_JMP_IMM(BPF_JA, 0, 0, 11),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 3, 3),
BPF_ST_MEM(BPF_DW, BPF_REG_2, -40, 0),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -40),
BPF_JMP_IMM(BPF_JA, 0, 0, 7),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 4, 3),
BPF_ST_MEM(BPF_DW, BPF_REG_2, -48, 0),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -48),
BPF_JMP_IMM(BPF_JA, 0, 0, 3),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 5, 0),
BPF_ST_MEM(BPF_DW, BPF_REG_2, -56, 0),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -56),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_delete_elem),
BPF_EXIT_INSN(),
},
.fixup = {24},
.result = ACCEPT,
},
{
"jump test 4",
.insns = {
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 1),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 2),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 3),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 4),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 1),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 2),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 3),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 4),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 1),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 2),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 3),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 4),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 1),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 2),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 3),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 4),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 1),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 2),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 3),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 4),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 1),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 2),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 3),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 4),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 1),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 2),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 3),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 4),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 1),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 2),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 3),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 4),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 1),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 2),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 3),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 4),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, BPF_REG_10, 0),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
},
{
"jump test 5",
.insns = {
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_MOV64_REG(BPF_REG_3, BPF_REG_2),
BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 2),
BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_3, -8),
BPF_JMP_IMM(BPF_JA, 0, 0, 2),
BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_2, -8),
BPF_JMP_IMM(BPF_JA, 0, 0, 0),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 2),
BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_3, -8),
BPF_JMP_IMM(BPF_JA, 0, 0, 2),
BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_2, -8),
BPF_JMP_IMM(BPF_JA, 0, 0, 0),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 2),
BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_3, -8),
BPF_JMP_IMM(BPF_JA, 0, 0, 2),
BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_2, -8),
BPF_JMP_IMM(BPF_JA, 0, 0, 0),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 2),
BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_3, -8),
BPF_JMP_IMM(BPF_JA, 0, 0, 2),
BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_2, -8),
BPF_JMP_IMM(BPF_JA, 0, 0, 0),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 2),
BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_3, -8),
BPF_JMP_IMM(BPF_JA, 0, 0, 2),
BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_2, -8),
BPF_JMP_IMM(BPF_JA, 0, 0, 0),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
},
{
"access skb fields ok",
.insns = {
BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, len)),
BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 0, 1),
BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, mark)),
BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 0, 1),
BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, pkt_type)),
BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 0, 1),
BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, queue_mapping)),
BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 0, 0),
BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, protocol)),
BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 0, 0),
BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, vlan_present)),
BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 0, 0),
BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, vlan_tci)),
BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 0, 0),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
},
{
"access skb fields bad1",
.insns = {
BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, -4),
BPF_EXIT_INSN(),
},
.errstr = "invalid bpf_context access",
.result = REJECT,
},
{
"access skb fields bad2",
.insns = {
BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 9),
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
BPF_EXIT_INSN(),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, pkt_type)),
BPF_EXIT_INSN(),
},
.fixup = {4},
.errstr = "different pointers",
.result = REJECT,
},
{
"access skb fields bad3",
.insns = {
BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 2),
BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, pkt_type)),
BPF_EXIT_INSN(),
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
BPF_EXIT_INSN(),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_JMP_IMM(BPF_JA, 0, 0, -12),
},
.fixup = {6},
.errstr = "different pointers",
.result = REJECT,
},
{
"access skb fields bad4",
.insns = {
BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 3),
BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_1,
offsetof(struct __sk_buff, len)),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
BPF_EXIT_INSN(),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_JMP_IMM(BPF_JA, 0, 0, -13),
},
.fixup = {7},
.errstr = "different pointers",
.result = REJECT,
},
};
static int probe_filter_length(struct bpf_insn *fp)
{
int len = 0;
for (len = MAX_INSNS - 1; len > 0; --len)
if (fp[len].code != 0 || fp[len].imm != 0)
break;
return len + 1;
}
static int create_map(void)
{
long long key, value = 0;
int map_fd;
map_fd = bpf_create_map(BPF_MAP_TYPE_HASH, sizeof(key), sizeof(value), 1024);
if (map_fd < 0) {
printf("failed to create map '%s'\n", strerror(errno));
}
return map_fd;
}
static int test(void)
{
int prog_fd, i, pass_cnt = 0, err_cnt = 0;
for (i = 0; i < ARRAY_SIZE(tests); i++) {
struct bpf_insn *prog = tests[i].insns;
int prog_len = probe_filter_length(prog);
int *fixup = tests[i].fixup;
int map_fd = -1;
if (*fixup) {
map_fd = create_map();
do {
prog[*fixup].imm = map_fd;
fixup++;
} while (*fixup);
}
printf("#%d %s ", i, tests[i].descr);
prog_fd = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, prog,
prog_len * sizeof(struct bpf_insn),
"GPL", 0);
if (tests[i].result == ACCEPT) {
if (prog_fd < 0) {
printf("FAIL\nfailed to load prog '%s'\n",
strerror(errno));
printf("%s", bpf_log_buf);
err_cnt++;
goto fail;
}
} else {
if (prog_fd >= 0) {
printf("FAIL\nunexpected success to load\n");
printf("%s", bpf_log_buf);
err_cnt++;
goto fail;
}
if (strstr(bpf_log_buf, tests[i].errstr) == 0) {
printf("FAIL\nunexpected error message: %s",
bpf_log_buf);
err_cnt++;
goto fail;
}
}
pass_cnt++;
printf("OK\n");
fail:
if (map_fd >= 0)
close(map_fd);
close(prog_fd);
}
printf("Summary: %d PASSED, %d FAILED\n", pass_cnt, err_cnt);
return 0;
}
int main(void)
{
return test();
}
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