bpf: Wrap aux data inside bpf_sanitize_info container

commit 3d0220f upstream.

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 <[email protected]>
Reviewed-by: Piotr Krysiuk <[email protected]>
Acked-by: Alexei Starovoitov <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: borkmann

kernel/bpf/verifier.c

@@ -5743,15 +5743,19 @@ 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;
@@ -5780,8 +5784,8 @@ 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;
@@ -5942,7 +5946,7 @@ 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;
@@ -6011,7 +6015,7 @@ 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);
 	}
@@ -6152,7 +6156,7 @@ 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);
 	}