Jason Wang
2021-Jul-19 03:30 UTC
[PATCH 2/2] vhost: Fix the calculation in vhost_overflow()
? 2021/7/16 ??6:22, Xie Yongji ??:> 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 at redhat.com> > Signed-off-by: Xie Yongji <xieyongji at 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 at redhat.com>> > /* Caller should have vq mutex and device mutex. */