Re: [PATCH] net: remove duplicate fetch in sock_getsockopt

[David Miller]

From: JingYi Hou <houjingyi647@xxxxxxxxx>
Date: Mon, 17 Jun 2019 14:56:05 +0800

> In sock_getsockopt(), 'optlen' is fetched the first time from userspace.
> 'len < 0' is then checked. Then in condition 'SO_MEMINFO', 'optlen' is
> fetched the second time from userspace.
> 
> If change it between two fetches may cause security problems or unexpected
> behaivor, and there is no reason to fetch it a second time.
> 
> To fix this, we need to remove the second fetch.
> 
> Signed-off-by: JingYi Hou <houjingyi647@xxxxxxxxx>

Applied and queued up for -stable, thanks.