From: Xie Yongji <xieyongji@bytedance.com>
To: mst@redhat.com, jasowang@redhat.com, dan.carpenter@oracle.com
Cc: virtualization@lists.linux-foundation.org, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v2 2/2] vhost: Fix the calculation in vhost_overflow()
Date: Wed, 28 Jul 2021 21:07:56 +0800 [thread overview]
Message-ID: <20210728130756.97-2-xieyongji@bytedance.com> (raw)
In-Reply-To: <20210728130756.97-1-xieyongji@bytedance.com>
This fixes the incorrect calculation for integer overflow
when the last address of iova range is 0xffffffff.
Fixes: ec33d031a14b ("vhost: detect 32 bit integer wrap around“)
Reported-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
drivers/vhost/vhost.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index b9e853e6094d..59edb5a1ffe2 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -735,10 +735,16 @@ static bool log_access_ok(void __user *log_base, u64 addr, unsigned long sz)
(sz + VHOST_PAGE_SIZE * 8 - 1) / VHOST_PAGE_SIZE / 8);
}
+/* Make sure 64 bit math will not overflow. */
static bool vhost_overflow(u64 uaddr, u64 size)
{
- /* Make sure 64 bit math will not overflow. */
- return uaddr > ULONG_MAX || size > ULONG_MAX || uaddr > ULONG_MAX - size;
+ if (uaddr > ULONG_MAX || size > ULONG_MAX)
+ return true;
+
+ if (!size)
+ return false;
+
+ return uaddr > ULONG_MAX - size + 1;
}
/* Caller should have vq mutex and device mutex. */
--
2.11.0
prev parent reply other threads:[~2021-07-28 13:08 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-28 13:07 [PATCH v2 1/2] vhost-vdpa: Fix integer overflow in vhost_vdpa_process_iotlb_update() Xie Yongji
2021-07-28 13:07 ` Xie Yongji [this message]
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