[lkml]   [2019]   [Jun]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] fix double-fetch bug in sock_getsockopt()
From: JingYi Hou <>
Date: Thu, 13 Jun 2019 18:44:57 +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 without check.
> if a malicious user can change it between two fetches may cause security
> problems or unexpected behaivor.
> To fix this, we need to recheck it in the second fetch.
> Signed-off-by: JingYi Hou <>

THere is no reason to fetch len a second time, so please just remove
the get_user() call here instead.

Also, please format your Subject line properly with appropriate subsystem
prefixes etc.

 \ /
  Last update: 2019-06-15 22:33    [W:0.070 / U:1.728 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site