Mailing List Archive: denied marking stack executable

Hi!

I've just tried to run one game which works several months ago and get
segfault with this message in kernel log:

2014-07-15_21:38:42.73335 kern.alert: grsec: denied marking stack executable as requested by PT_GNU_STACK marking in /mnt/storage/games/DungeonDefenders/UDKGame/Binaries/DungeonDefenders-x86 by /lib32/ld-2.17.so[ld-linux.so.2:2818] uid/euid:1000/1000 gid/egid:1000/1000, parent /usr/bin/ldd[ldd:2817] uid/euid:1000/1000 gid/egid:1000/1000
2014-07-15_21:38:42.73338 kern.alert: grsec: denied RWX mprotect of <stack> by /lib32/ld-2.17.so[ld-linux.so.2:2818] uid/euid:1000/1000 gid/egid:1000/1000, parent /usr/bin/ldd[ldd:2817] uid/euid:1000/1000 gid/egid:1000/1000

Looks like it can't be fixed using paxctl-ng, so how to work around it?

Also, looks like when I try to execute it in most cases it segfault
without any messages in kernel log, not sure why.

--
WBR, Alex.

On 16 Jul 2014 at 0:47, Alex Efros wrote:

> 2014-07-15_21:38:42.73335 kern.alert: grsec: denied marking stack executable as requested by PT_GNU_STACK marking in /mnt/storage/games/DungeonDefenders/UDKGame/Binaries/DungeonDefenders-x86 by /lib32/ld-2.17.so[ld-linux.so.2:2818] uid/euid:1000/1000 gid/egid:1000/1000, parent /usr/bin/ldd[ldd:2817] uid/euid:1000/1000 gid/egid:1000/1000
> 2014-07-15_21:38:42.73338 kern.alert: grsec: denied RWX mprotect of <stack> by /lib32/ld-2.17.so[ld-linux.so.2:2818] uid/euid:1000/1000 gid/egid:1000/1000, parent /usr/bin/ldd[ldd:2817] uid/euid:1000/1000 gid/egid:1000/1000
>
> Looks like it can't be fixed using paxctl-ng, so how to work around it?

it could be fixed with disabling MPROTECT but this program probably just
has the usual buggy GNU_STACK marking so try execstack -c on it. if it has
self-checking logic however you'll need to resort to setting the PaX flags.