1 files changed, 31 insertions, 8 deletions

diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 23ab31b967a1..735abf426a06 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -751,6 +751,8 @@ static int fuse_parse_param(struct fs_context *fsc, struct fs_parameter *param)
 	struct fs_parse_result result;
 	struct fuse_fs_context *ctx = fsc->fs_private;
 	int opt;
+	kuid_t kuid;
+	kgid_t kgid;
 
 	if (fsc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
 		/*
@@ -795,16 +797,30 @@ static int fuse_parse_param(struct fs_context *fsc, struct fs_parameter *param)
 		break;
 
 	case OPT_USER_ID:
-		ctx->user_id = make_kuid(fsc->user_ns, result.uint_32);
-		if (!uid_valid(ctx->user_id))
+		kuid =  make_kuid(fsc->user_ns, result.uint_32);
+		if (!uid_valid(kuid))
 			return invalfc(fsc, "Invalid user_id");
+		/*
+		 * The requested uid must be representable in the
+		 * filesystem's idmapping.
+		 */
+		if (!kuid_has_mapping(fsc->user_ns, kuid))
+			return invalfc(fsc, "Invalid user_id");
+		ctx->user_id = kuid;
 		ctx->user_id_present = true;
 		break;
 
 	case OPT_GROUP_ID:
-		ctx->group_id = make_kgid(fsc->user_ns, result.uint_32);
-		if (!gid_valid(ctx->group_id))
+		kgid = make_kgid(fsc->user_ns, result.uint_32);;
+		if (!gid_valid(kgid))
+			return invalfc(fsc, "Invalid group_id");
+		/*
+		 * The requested gid must be representable in the
+		 * filesystem's idmapping.
+		 */
+		if (!kgid_has_mapping(fsc->user_ns, kgid))
 			return invalfc(fsc, "Invalid group_id");
+		ctx->group_id = kgid;
 		ctx->group_id_present = true;
 		break;
 
@@ -936,6 +952,14 @@ void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm,
 }
 EXPORT_SYMBOL_GPL(fuse_conn_init);
 
+static void delayed_release(struct rcu_head *p)
+{
+	struct fuse_conn *fc = container_of(p, struct fuse_conn, rcu);
+
+	put_user_ns(fc->user_ns);
+	fc->release(fc);
+}
+
 void fuse_conn_put(struct fuse_conn *fc)
 {
 	if (refcount_dec_and_test(&fc->count)) {
@@ -947,13 +971,12 @@ void fuse_conn_put(struct fuse_conn *fc)
 		if (fiq->ops->release)
 			fiq->ops->release(fiq);
 		put_pid_ns(fc->pid_ns);
-		put_user_ns(fc->user_ns);
 		bucket = rcu_dereference_protected(fc->curr_bucket, 1);
 		if (bucket) {
 			WARN_ON(atomic_read(&bucket->count) != 1);
 			kfree(bucket);
 		}
-		fc->release(fc);
+		call_rcu(&fc->rcu, delayed_release);
 	}
 }
 EXPORT_SYMBOL_GPL(fuse_conn_put);
@@ -1371,7 +1394,7 @@ EXPORT_SYMBOL_GPL(fuse_send_init);
 void fuse_free_conn(struct fuse_conn *fc)
 {
 	WARN_ON(!list_empty(&fc->devices));
-	kfree_rcu(fc, rcu);
+	kfree(fc);
 }
 EXPORT_SYMBOL_GPL(fuse_free_conn);
 
@@ -1905,7 +1928,7 @@ static void fuse_sb_destroy(struct super_block *sb)
 void fuse_mount_destroy(struct fuse_mount *fm)
 {
 	fuse_conn_put(fm->fc);
-	kfree(fm);
+	kfree_rcu(fm, rcu);
 }
 EXPORT_SYMBOL(fuse_mount_destroy);