diff options
| -rw-r--r-- | kernel/bpf/verifier.c | 9 | ||||
| -rw-r--r-- | samples/bpf/test_verifier.c | 22 |
2 files changed, 29 insertions, 2 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 66bec36..47dcd3a 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1637,6 +1637,8 @@ static int do_check(struct verifier_env *env) if (err) return err; + src_reg_type = regs[insn->src_reg].type; + /* check that memory (src_reg + off) is readable, * the state of dst_reg will be updated by this func */ @@ -1646,9 +1648,12 @@ static int do_check(struct verifier_env *env) if (err) return err; - src_reg_type = regs[insn->src_reg].type; + if (BPF_SIZE(insn->code) != BPF_W) { + insn_idx++; + continue; + } - if (insn->imm == 0 && BPF_SIZE(insn->code) == BPF_W) { + if (insn->imm == 0) { /* saw a valid insn * dst_reg = *(u32 *)(src_reg + off) * use reserved 'imm' field to mark this insn diff --git a/samples/bpf/test_verifier.c b/samples/bpf/test_verifier.c index 9ab6456..12f3780 100644 --- a/samples/bpf/test_verifier.c +++ b/samples/bpf/test_verifier.c @@ -721,6 +721,28 @@ static struct bpf_test tests[] = { .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) |