Subject: grep critical local DoS from userspace

From: [email-masked]
Date: Thu, 23 Mar 2017 20:11:58 +0100

Hello,

Today I searched some files and... my server goes to hell (crash).

replication:

0. log into root or user account (whatever)
1. make a huge empty file (eg. 10 GB of zeros)
(my is: -rw-r--r-- 1 root root 10485760000 Feb 28 18:14 testfile.out)
2. grep -Hi "\/tmp\/" * 2>/dev/null
3. crash (probably due to out of memory)

... damn...

greetz,
-- 
Tomasz 'BloodMan' Tomkowiak