ExecShield In C6 Or C7 Kernels?

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I’m trying to figure out if the stock kernels for CentOS-6 and/or CentOS-7
have ExecShield compiled in, and if so, if it is turned on by default.

On my local C7 box I’ve been looking at/for indicators without a lot of success:

/usr/lib/sysctl.d/00-system.conf. does not mention ExecShield at all.
/proc/sys/kernel has no entries for exec_shield no mention of execshield in any of the files in /etc/grub.d

So, as far as I can see, there are no settings that I would expect to force ExecShield to an ON setting.

I DO see, in /proc/sys/kernel, a file named randomize_va_space, and it contains a value of “2”.

I’ve been googling (well, actually DuckDuckGo-ing) and most of the articles I find regarding ExecShield are 3-10 years old.

I’d appreciate pointers/guides/info on ExecShield in C6 or C7.

thanks in advance!

Fred

3 thoughts on - ExecShield In C6 Or C7 Kernels?

  • According to what I’ve read, Exec Shield is enabled in CentOS-6 and -7
    by default. In CentOS-6, you can see it by:

    sysctl -a | grep -i shield

    The sysctl command also allows you to disable it. But in CentOS-7 you cannot change it any more.

    Akemi

  • I’ve also realized if you have No Execute(NX) or Execute Disable(XD)
    protection enabled in your BIOS, you can’t access kernel.exec-shield sysctl parameter.

    [root@CentOS7 ~]# dmesg | grep ‘[NX|DX]*protection’
    [ 0.000000] NX (Execute Disable) protection: active

    [root@CentOS7 ~]# sysctl kernel.exec-shield sysctl: cannot stat /proc/sys/kernel/exec-shield: No such file or directory

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