bpf: Use correct permission flag for mixed signed bounds arithmetic

We forbid adding unknown scalars with mixed signed bounds due to the spectre v1 masking mitigation. Hence this also needs bypass_spec_v1 flag instead of allow_ptr_leaks. Fixes: 2c78ee8 ("bpf: Implement CAP_BPF") Signed-off-by: Daniel Borkmann <[email protected]> Reviewed-by: John Fastabend <[email protected]> Acked-by: Alexei Starovoitov <[email protected]>
congwang · Apr 16, 2021 · 9601148 · 9601148
1 parent afd0be7
commit 9601148
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
@@ -6085,7 +6085,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 			dst, reg_type_str[ptr_reg->type]);
 		return -EACCES;
 	case PTR_TO_MAP_VALUE:
-		if (!env->allow_ptr_leaks && !known && (smin_val < 0) != (smax_val < 0)) {
+		if (!env->env->bypass_spec_v1 && !known && (smin_val < 0) != (smax_val < 0)) {
 			verbose(env, "R%d has unknown scalar with mixed signed bounds, pointer arithmetic with it prohibited for !root\n",
 				off_reg == dst_reg ? dst : src);
 			return -EACCES;