Is PIE randomization breaking klibc binaries?

From: Ulrich Kunitz
Date: Fri Jul 20 2007 - 17:43:52 EST


Since this week new linux-2.6/master kernels don't work with my
initial ram disks. The sleep binary runs repeatingly into
segmentation faults until the Busybox shell starts. My system is a
x86-64 with Kubuntu Feisty Fawn.

By bisecting I found out that the PIE randomization patch (commit 60bfba7e)
appears to cause the segmentation faults.

Digging further into the issue I found out, that the sleep binary
on the initial ramdisk is a klibc binary. /usr/bin/file says it is
statically linked and uses shared libraries. I have no clue about
klibc, but the binaries seem to be statically linked, but load a
shared library; probably at a fixed address. Other klibc binaries are also
running into segmentation faults. Busybox is working, but it is
statically linked and doesn't use a shared library.

It looks like that the PIE randomization patch breaks klibc
binaries on x86-64.

--
Uli Kunitz
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