bpf: Wrap aux data inside bpf_sanitize_info container

Add a container structure struct bpf_sanitize_info which holds
the current aux info, and update call-sites to sanitize_ptr_alu()
to pass it in. This is needed for passing in additional state
later on.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Piotr Krysiuk <piotras@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 09849e4..98690f5 100644 (file)
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -6486,15 +6486,19 @@ static bool sanitize_needed(u8 opcode)
        return opcode == BPF_ADD || opcode == BPF_SUB;
 }
 
+struct bpf_sanitize_info {
+       struct bpf_insn_aux_data aux;
+};
+
 static int sanitize_ptr_alu(struct bpf_verifier_env *env,
                            struct bpf_insn *insn,
                            const struct bpf_reg_state *ptr_reg,
                            const struct bpf_reg_state *off_reg,
                            struct bpf_reg_state *dst_reg,
-                           struct bpf_insn_aux_data *tmp_aux,
+                           struct bpf_sanitize_info *info,
                            const bool commit_window)
 {
-       struct bpf_insn_aux_data *aux = commit_window ? cur_aux(env) : tmp_aux;
+       struct bpf_insn_aux_data *aux = commit_window ? cur_aux(env) : &info->aux;
        struct bpf_verifier_state *vstate = env->cur_state;
        bool off_is_imm = tnum_is_const(off_reg->var_off);
        bool off_is_neg = off_reg->smin_value < 0;
@@ -6523,8 +6527,8 @@ static int sanitize_ptr_alu(struct bpf_verifier_env *env,
                /* In commit phase we narrow the masking window based on
                 * the observed pointer move after the simulated operation.
                 */
-               alu_state = tmp_aux->alu_state;
-               alu_limit = abs(tmp_aux->alu_limit - alu_limit);
+               alu_state = info->aux.alu_state;
+               alu_limit = abs(info->aux.alu_limit - alu_limit);
        } else {
                alu_state  = off_is_neg ? BPF_ALU_NEG_VALUE : 0;
                alu_state |= off_is_imm ? BPF_ALU_IMMEDIATE : 0;
@@ -6685,7 +6689,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
            smin_ptr = ptr_reg->smin_value, smax_ptr = ptr_reg->smax_value;
        u64 umin_val = off_reg->umin_value, umax_val = off_reg->umax_value,
            umin_ptr = ptr_reg->umin_value, umax_ptr = ptr_reg->umax_value;
-       struct bpf_insn_aux_data tmp_aux = {};
+       struct bpf_sanitize_info info = {};
        u8 opcode = BPF_OP(insn->code);
        u32 dst = insn->dst_reg;
        int ret;
@@ -6754,7 +6758,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 
        if (sanitize_needed(opcode)) {
                ret = sanitize_ptr_alu(env, insn, ptr_reg, off_reg, dst_reg,
-                                      &tmp_aux, false);
+                                      &info, false);
                if (ret < 0)
                        return sanitize_err(env, insn, ret, off_reg, dst_reg);
        }
@@ -6895,7 +6899,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
                return -EACCES;
        if (sanitize_needed(opcode)) {
                ret = sanitize_ptr_alu(env, insn, dst_reg, off_reg, dst_reg,
-                                      &tmp_aux, true);
+                                      &info, true);
                if (ret < 0)
                        return sanitize_err(env, insn, ret, off_reg, dst_reg);
        }