diff options
| -rw-r--r-- | kernel/bpf/verifier.c | 6 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/test_verifier.c | 26 |
2 files changed, 30 insertions, 2 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 25e47c195874..e948303a0ea8 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -3238,8 +3238,8 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) } } - /* check dest operand */ - err = check_reg_arg(env, insn->dst_reg, DST_OP); + /* check dest operand, mark as required later */ + err = check_reg_arg(env, insn->dst_reg, DST_OP_NO_MARK); if (err) return err; @@ -3265,6 +3265,8 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) /* case: R = imm * remember the value we stored into this reg */ + /* clear any state __mark_reg_known doesn't set */ + mark_reg_unknown(env, regs, insn->dst_reg); regs[insn->dst_reg].type = SCALAR_VALUE; if (BPF_CLASS(insn->code) == BPF_ALU64) { __mark_reg_known(regs + insn->dst_reg, diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index f5f7bcc96046..c582afba9d1f 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -12332,6 +12332,32 @@ static struct bpf_test tests[] = { .result = REJECT, .errstr = "variable ctx access var_off=(0x0; 0x4)", }, + { + "mov64 src == dst", + .insns = { + BPF_MOV64_IMM(BPF_REG_2, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_2), + // Check bounds are OK + BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_2), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = ACCEPT, + }, + { + "mov64 src != dst", + .insns = { + BPF_MOV64_IMM(BPF_REG_3, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_3), + // Check bounds are OK + BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_2), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = ACCEPT, + }, }; static int probe_filter_length(const struct bpf_insn *fp) |