* [PATCH v2 1/2] vhost-vdpa: Fix integer overflow in vhost_vdpa_process_iotlb_update()
@ 2021-07-28 13:07 Xie Yongji
2021-07-28 13:07 ` [PATCH v2 2/2] vhost: Fix the calculation in vhost_overflow() Xie Yongji
0 siblings, 1 reply; 2+ messages in thread
From: Xie Yongji @ 2021-07-28 13:07 UTC (permalink / raw)
To: mst, jasowang, dan.carpenter; +Cc: virtualization, kvm, linux-kernel
The "msg->iova + msg->size" addition can have an integer overflow
if the iotlb message is from a malicious user space application.
So let's fix it.
Fixes: 1b48dc03e575 ("vhost: vdpa: report iova range")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
drivers/vhost/vdpa.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 210ab35a7ebf..9479f7f79217 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -614,7 +614,8 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
long pinned;
int ret = 0;
- if (msg->iova < v->range.first ||
+ if (msg->iova < v->range.first || !msg->size ||
+ msg->iova > U64_MAX - msg->size + 1 ||
msg->iova + msg->size - 1 > v->range.last)
return -EINVAL;
--
2.11.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH v2 2/2] vhost: Fix the calculation in vhost_overflow()
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
0 siblings, 0 replies; 2+ messages in thread
From: Xie Yongji @ 2021-07-28 13:07 UTC (permalink / raw)
To: mst, jasowang, dan.carpenter; +Cc: virtualization, kvm, linux-kernel
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
^ permalink raw reply related [flat|nested] 2+ messages in thread
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