[PATCH v3 08/17] tools/xenstore: don't allow creating too many nodes in a transaction

[Juergen Gross <jgross@suse.com>]

The accounting for the number of nodes of a domain in an active
transaction is not working correctly, as it allows to create arbitrary
number of nodes. The transaction will finally fail due to exceeding
the number of nodes quota, but before closing the transaction an
unprivileged guest could cause Xenstore to use a lot of memory.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
 tools/xenstore/xenstored_domain.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/tools/xenstore/xenstored_domain.c b/tools/xenstore/xenstored_domain.c
index edfe5809be..07d91eb50c 100644
--- a/tools/xenstore/xenstored_domain.c
+++ b/tools/xenstore/xenstored_domain.c
@@ -1129,9 +1129,8 @@ int domain_nbentry_fix(unsigned int domid, int num, bool update)
 
 int domain_nbentry(struct connection *conn)
 {
-	return (domain_is_unprivileged(conn))
-		? conn->domain->nbentry
-		: 0;
+	return domain_is_unprivileged(conn)
+	       ? domain_nbentry_add(conn, conn->id, 0, true) : 0;
 }
 
 static bool domain_chk_quota(struct domain *domain, int mem)
-- 
2.35.3