diff mbox series

[2/2] vhost: Fix the calculation in vhost_overflow()

Message ID 20210716102239.96-2-xieyongji@bytedance.com (mailing list archive)
State New, archived
Headers show
Series [1/2] vhost-vdpa: Fix integer overflow in vhost_vdpa_process_iotlb_update() | expand

Commit Message

Xie Yongji July 16, 2021, 10:22 a.m. UTC
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>
---
 drivers/vhost/vhost.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Jason Wang July 19, 2021, 3:30 a.m. UTC | #1
在 2021/7/16 下午6:22, Xie Yongji 写道:
> 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>
> ---
>   drivers/vhost/vhost.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index b9e853e6094d..a9fd1b311d2f 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -738,7 +738,8 @@ static bool log_access_ok(void __user *log_base, u64 addr, unsigned long sz)
>   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;
> +	return uaddr > ULONG_MAX || size > ULONG_MAX ||
> +	       uaddr - 1 > ULONG_MAX - size;
>   }


Acked-by: Jason Wang <jasowang@redhat.com>


>   
>   /* Caller should have vq mutex and device mutex. */
diff mbox series

Patch

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index b9e853e6094d..a9fd1b311d2f 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -738,7 +738,8 @@  static bool log_access_ok(void __user *log_base, u64 addr, unsigned long sz)
 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;
+	return uaddr > ULONG_MAX || size > ULONG_MAX ||
+	       uaddr - 1 > ULONG_MAX - size;
 }
 
 /* Caller should have vq mutex and device mutex. */