render / rpms / libvirt

Forked from rpms/libvirt 9 months ago
Clone
99cbc7
From f7a3585a8bee3d91b1cd57dabd4c2b506afef596 Mon Sep 17 00:00:00 2001
99cbc7
Message-Id: <f7a3585a8bee3d91b1cd57dabd4c2b506afef596@dist-git>
99cbc7
From: Michal Privoznik <mprivozn@redhat.com>
99cbc7
Date: Mon, 21 Jan 2019 09:04:10 -0500
99cbc7
Subject: [PATCH] util: Don't overflow in virRandomBits
99cbc7
MIME-Version: 1.0
99cbc7
Content-Type: text/plain; charset=UTF-8
99cbc7
Content-Transfer-Encoding: 8bit
99cbc7
99cbc7
https://bugzilla.redhat.com/show_bug.cgi?id=1667329 (RHEL 7.6.z)
99cbc7
https://bugzilla.redhat.com/show_bug.cgi?id=1652894 (RHEL 7.7)
99cbc7
99cbc7
The function is supposed to return up to 64bit long integer. In
99cbc7
order to do that it calls virRandomBytes() to fill the integer
99cbc7
with random bytes and then masks out everything but requested
99cbc7
bits. However, when doing that it shifts 1U and not 1ULL. So
99cbc7
effectively, requesting 32 random bis or more always return 0
99cbc7
which is not random enough.
99cbc7
99cbc7
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
99cbc7
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
99cbc7
Reviewed-by: Pino Toscano <ptoscano@redhat.com>
99cbc7
(cherry picked from commit 78c47a92ecb450c9f8bcabd35da7006dc2547882)
99cbc7
Signed-off-by: John Ferlan <jferlan@redhat.com>
99cbc7
Message-Id: <20190121140412.27804-2-jferlan@redhat.com>
99cbc7
Reviewed-by: Erik Skultety <eskultet@redhat.com>
99cbc7
---
99cbc7
 src/util/virrandom.c | 2 +-
99cbc7
 1 file changed, 1 insertion(+), 1 deletion(-)
99cbc7
99cbc7
diff --git a/src/util/virrandom.c b/src/util/virrandom.c
99cbc7
index 01cc82a052..3c011a8615 100644
99cbc7
--- a/src/util/virrandom.c
99cbc7
+++ b/src/util/virrandom.c
99cbc7
@@ -68,7 +68,7 @@ uint64_t virRandomBits(int nbits)
99cbc7
         return 0;
99cbc7
     }
99cbc7
 
99cbc7
-    ret &= (1U << nbits) - 1;
99cbc7
+    ret &= (1ULL << nbits) - 1;
99cbc7
     return ret;
99cbc7
 }
99cbc7
 
99cbc7
-- 
99cbc7
2.21.0
99cbc7