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.

As reported by covscan:

expr_evaluate_concat() calls concat_subtype_lookup(type, --off), the signed 'off' might become negative as far as I can tell. The latter function in turn calls concat_subtype_id(type, n) where 'n' is '--off' converted to unsigned. In concat_subtype_id(), 'n' is used in the following expression:

return (type >> TYPE_BITS * n) & TYPE_MASK;

So 'TYPE_BITS * n' might exceed the number of bits in 'type' and therefore lead to undefined behaviour.

This is the upstream fix to backport:

commit 83e52f7a7f5eaa893e146d23ff2e9292179f9485
Author: Phil Sutter <phil>
Date:   Tue Aug 30 19:39:52 2016 +0200

    evaluate: Avoid undefined behaviour in concat_subtype_id()
    
    For the left side of a concat expression, dtype is NULL and therefore
    off is 0. In that case the code expects to get a datatype of
    TYPE_INVALID, but this is fragile as the output of concat_subtype_id()
    is undefined for n > 32 / TYPE_BITS.
    
    To fix this, call datatype_lookup() directly passing the expected
    TYPE_INVALID as argument if off is 0.
    
    Signed-off-by: Phil Sutter <phil>
    Signed-off-by: Pablo Neira Ayuso <pablo>

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2017:2047