diff options
| -rw-r--r-- | kernel/bpf/verifier.c | 37 |
1 files changed, 33 insertions, 4 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index f6b4c7148c3e..a6af3166acae 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1269,6 +1269,24 @@ static bool is_reg64(struct bpf_verifier_env *env, struct bpf_insn *insn, return true; } +/* Return TRUE if INSN doesn't have explicit value define. */ +static bool insn_no_def(struct bpf_insn *insn) +{ + u8 class = BPF_CLASS(insn->code); + + return (class == BPF_JMP || class == BPF_JMP32 || + class == BPF_STX || class == BPF_ST); +} + +/* Return TRUE if INSN has defined any 32-bit value explicitly. */ +static bool insn_has_def32(struct bpf_verifier_env *env, struct bpf_insn *insn) +{ + if (insn_no_def(insn)) + return false; + + return !is_reg64(env, insn, insn->dst_reg, NULL, DST_OP); +} + static void mark_insn_zext(struct bpf_verifier_env *env, struct bpf_reg_state *reg) { @@ -7298,14 +7316,23 @@ static void convert_pseudo_ld_imm64(struct bpf_verifier_env *env) * insni[off, off + cnt). Adjust corresponding insn_aux_data by copying * [0, off) and [off, end) to new locations, so the patched range stays zero */ -static int adjust_insn_aux_data(struct bpf_verifier_env *env, u32 prog_len, - u32 off, u32 cnt) +static int adjust_insn_aux_data(struct bpf_verifier_env *env, + struct bpf_prog *new_prog, u32 off, u32 cnt) { struct bpf_insn_aux_data *new_data, *old_data = env->insn_aux_data; + struct bpf_insn *insn = new_prog->insnsi; + u32 prog_len; int i; + /* aux info at OFF always needs adjustment, no matter fast path + * (cnt == 1) is taken or not. There is no guarantee INSN at OFF is the + * original insn at old prog. + */ + old_data[off].zext_dst = insn_has_def32(env, insn + off + cnt - 1); + if (cnt == 1) return 0; + prog_len = new_prog->len; new_data = vzalloc(array_size(prog_len, sizeof(struct bpf_insn_aux_data))); if (!new_data) @@ -7313,8 +7340,10 @@ static int adjust_insn_aux_data(struct bpf_verifier_env *env, u32 prog_len, memcpy(new_data, old_data, sizeof(struct bpf_insn_aux_data) * off); memcpy(new_data + off + cnt - 1, old_data + off, sizeof(struct bpf_insn_aux_data) * (prog_len - off - cnt + 1)); - for (i = off; i < off + cnt - 1; i++) + for (i = off; i < off + cnt - 1; i++) { new_data[i].seen = true; + new_data[i].zext_dst = insn_has_def32(env, insn + i); + } env->insn_aux_data = new_data; vfree(old_data); return 0; @@ -7347,7 +7376,7 @@ static struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 of env->insn_aux_data[off].orig_idx); return NULL; } - if (adjust_insn_aux_data(env, new_prog->len, off, len)) + if (adjust_insn_aux_data(env, new_prog, off, len)) return NULL; adjust_subprog_starts(env, off, len); return new_prog; |