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@xxxxxxxxxx>
Signed-off-by: Xie Yongji <xieyongji@xxxxxxxxxxxxx>
---
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;
}
/* Caller should have vq mutex and device mutex. */
--
2.11.0
