diff options
| -rw-r--r-- | kernel/bpf/verifier.c | 11 | ||||
| -rw-r--r-- | samples/bpf/test_verifier.c | 18 |
2 files changed, 23 insertions, 6 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 7c9f94c53441..64fcab1d8cd9 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1749,6 +1749,17 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) return 0; } else if (opcode == BPF_ADD && BPF_CLASS(insn->code) == BPF_ALU64 && + dst_reg->type == PTR_TO_STACK && + ((BPF_SRC(insn->code) == BPF_X && + regs[insn->src_reg].type == CONST_IMM) || + BPF_SRC(insn->code) == BPF_K)) { + if (BPF_SRC(insn->code) == BPF_X) + dst_reg->imm += regs[insn->src_reg].imm; + else + dst_reg->imm += insn->imm; + return 0; + } else if (opcode == BPF_ADD && + BPF_CLASS(insn->code) == BPF_ALU64 && (dst_reg->type == PTR_TO_PACKET || (BPF_SRC(insn->code) == BPF_X && regs[insn->src_reg].type == PTR_TO_PACKET))) { diff --git a/samples/bpf/test_verifier.c b/samples/bpf/test_verifier.c index 369ffaad3799..dc7dec9e64ba 100644 --- a/samples/bpf/test_verifier.c +++ b/samples/bpf/test_verifier.c @@ -1218,16 +1218,22 @@ static struct bpf_test tests[] = { .result = ACCEPT, }, { - "unpriv: obfuscate stack pointer", + "stack pointer arithmetic", .insns = { - BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), - BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), - BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_MOV64_IMM(BPF_REG_1, 4), + BPF_JMP_IMM(BPF_JA, 0, 0, 0), + BPF_MOV64_REG(BPF_REG_7, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -10), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_7), + BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_1), + BPF_ST_MEM(0, BPF_REG_2, 4, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_7), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, 8), + BPF_ST_MEM(0, BPF_REG_2, 4, 0), BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), }, - .errstr_unpriv = "R2 pointer arithmetic", - .result_unpriv = REJECT, .result = ACCEPT, }, { |