Note: This bug is displayed in read-only format because the product is no longer active in Red Hat Bugzilla.

RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.

Running
valgrind /bin/sh
or just valgrind on a simple:
#include <stdio.h>
#include <unistd.h>

int 
main (void)
{
  printf ("%ld\n", sysconf (_SC_PHYS_PAGES));
  return 0;
}
results in errors like:
==13654== Invalid read of size 8
==13654==    at 0x802A9BB824: _IO_vfscanf@@GLIBC_2.4 (in /lib64/libc-2.12.so)
==13654==    by 0x802A9C696B: sscanf@@GLIBC_2.4 (in /lib64/libc-2.12.so)
==13654==    by 0x802AA57B4B: phys_pages_info (in /lib64/libc-2.12.so)
==13654==    by 0x802AA17E1B: sysconf (in /lib64/libc-2.12.so)
==13654==    by 0x100005C3: main (in /tmp/z)
==13654==  Address 0x7ff00cb20 is just below the stack ptr.  To suppress, use: --workaround-gcc296-bugs=yes

Could be a valgrind bug or glibc bug or gcc bug.
In any case, valgrind should be tested on several common programs on each of the RHEL6 arches where valgrind is included to make sure there aren't similar problems in RHEL6 GA.

Seems this isn't a bug in valgrind.

   0x802a9bb81c <._IO_vfscanf+732>:	std     r10,592(r31)
   0x802a9bb820 <._IO_vfscanf+736>:	addi    r1,r31,960
=> 0x802a9bb824 <._IO_vfscanf+740>:	ld      r3,592(r31)

As can be clearly seen, the stack pointer is first incremented and $r31+592 is below the 288 bytes long red zone.  So, very likely a gcc bug, going to build glibc now and see if I can reproduce it.

Ok, it is really a gcc bug, tracking it in http://gcc.gnu.org/PR44199.
Once gcc is fixed, glibc will need to be rebuilt.

Note the fixed gcc is already in SNapshot 5, so all that is needed to fix this bug is rebuild glibc.

Reproduced on ppc with old glibc, disappeared with new glibc. Moving to VERIFIED.

Red Hat Enterprise Linux 6.0 is now available and should resolve
the problem described in this bug report. This report is therefore being closed
with a resolution of CURRENTRELEASE. You may reopen this bug report if the
solution does not work for you.