grsecurity forums

Hey everyone.

I'm still new to this grsecurity stuff, so pardon my ignorance if this is an easy one.

I have grsecurity 1.9.4-2.4.18, with pretty much everything enabled, and for most
of my Slackware 8.0 systems, this has been fine.

However, one of my latest is having problems when I try to have Perl use the CPAN
archive to install packages. The problem is I'm not sure which grsecurity feature is
killing it. I just get a Segmentation Fault, and a

grsec: signal 11 send to (perl:5046) UID(0) EUID(0), parent (bash:29939) UID(0) EUID(0)"

in my logs. This happens right after Zlib (yes, I upgraded to 1.1.4) loads after a
"install" command.

Looking at a strace shows these events leading to the segfault:

old_mmap(NULL,4096, PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANONYMOUS,-1,0)=0x2da000
read(6,"\37\213\10\0\0027\237<\2\3\244\375\331\222\343J\226-\200"..., 16384)=16384
_llseek(6,0,[16384],SEEK_CUR)=0
--- SIGSEGV ---

I'm really not sure what would be tripping grsec, but it's probably obvious to everyone else.

Any help would be appreciated.

are you sure it's related to grsecurity? if grsecurity was stopping your program from doing something, it would notify you in a log. The signal log that you see is just showing you that the program caused a segmentation fault, which is due to an error in the programming of the application you were trying to run.

Hmmm.... I just compiled a new kernel with no GRSecurity, and it still doesn't work...

I guess you're off the hook.

I manage about 25 different boxes, all Slack-based but they all are roughly the same
code. This one has three twins, but the one difference was 2.4.18/GRSec 1.9.4 without
SYSCTL... the others are 2.4.17/GRSec 1.9.3a with SYSCTL. The CPAN/Perl script
works fine on the others, and since GRSec logged the signal 11 line, I thought it was the cause.

Barking up the wrong tree... of course, I'm not sure which tree to try next.

Well, thanks anyway. And thanks for the most kick-ass kernel mod I've ever seen.
GRSec RULES!

sysctl? I recently trapped on sysctl defaulting to disable all grsec-options... :-)