diff --git a/mm/shmem.c b/mm/shmem.c
index 10365ced5b1f..806741bbe4a6 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -3485,6 +3485,8 @@ static int shmem_parse_one(struct fs_context *fc, struct fs_parameter *param)
 	unsigned long long size;
 	char *rest;
 	int opt;
+	kuid_t kuid;
+	kgid_t kgid;
 
 	opt = fs_parse(fc, shmem_fs_parameters, param, &result);
 	if (opt < 0)
@@ -3520,14 +3522,32 @@ static int shmem_parse_one(struct fs_context *fc, struct fs_parameter *param)
 		ctx->mode = result.uint_32 & 07777;
 		break;
 	case Opt_uid:
-		ctx->uid = make_kuid(current_user_ns(), result.uint_32);
-		if (!uid_valid(ctx->uid))
+		kuid = make_kuid(current_user_ns(), result.uint_32);
+		if (!uid_valid(kuid))
 			goto bad_value;
+
+		/*
+		 * The requested uid must be representable in the
+		 * filesystem's idmapping.
+		 */
+		if (!kuid_has_mapping(fc->user_ns, kuid))
+			goto bad_value;
+
+		ctx->uid = kuid;
 		break;
 	case Opt_gid:
-		ctx->gid = make_kgid(current_user_ns(), result.uint_32);
-		if (!gid_valid(ctx->gid))
+		kgid = make_kgid(current_user_ns(), result.uint_32);
+		if (!gid_valid(kgid))
 			goto bad_value;
+
+		/*
+		 * The requested gid must be representable in the
+		 * filesystem's idmapping.
+		 */
+		if (!kgid_has_mapping(fc->user_ns, kgid))
+			goto bad_value;
+
+		ctx->gid = kgid;
 		break;
 	case Opt_huge:
 		ctx->huge = result.uint_32;