Messages in this thread Patch in this message | | | From | Xie Yongji <> | Subject | [PATCH 2/2] vhost: Fix the calculation in vhost_overflow() | Date | Fri, 16 Jul 2021 18:22:39 +0800 |
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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; } /* Caller should have vq mutex and device mutex. */ -- 2.11.0
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