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Author: Song Baohua
Source: wechat official account Linux Reading Code Field (ID: Linuxdev)
The principle of
Here’s a quick video. What happens if kernel access users don’t do access_OK?
https://v.qq.com/x/page/i1342goaqn3.html
Next, do your homework in depth!
case
For example, the following commit in the kernel introduces a serious security vulnerability (cVE-2017-5123) :
harm
An example of an attack is as follows:
http://www.freebuf.com/vuls/152412.html
Analysis and Utilization of Linux Kernel Waitid System Call Local Entitlement Vulnerability (CVE-2017-5123)
repair
The kernel commit fixes this:
Obviously, it just adds a call to access_OK.
More exciting updates… Welcome to wechat official account: Linux Reading Code Field (ID: Linuxdev)