Bug 1705899 - glibc: Backport libio vtable validation improvements [rhel-7.6.z]
Summary: glibc: Backport libio vtable validation improvements [rhel-7.6.z]
Alias: None
Product: Red Hat Enterprise Linux 7
Classification: Red Hat
Component: glibc
Version: 7.7
Hardware: All
OS: Linux
Target Milestone: rc
: ---
Assignee: Florian Weimer
QA Contact: Sergey Kolosov
Depends On: 1595191
TreeView+ depends on / blocked
Reported: 2019-05-03 07:48 UTC by RAD team bot copy to z-stream
Modified: 2022-03-13 17:05 UTC (History)
15 users (show)

Fixed In Version: glibc-2.17-260.el7_6.6
Doc Type: Bug Fix
Doc Text:
Cause: libio vtable validation is a security hardening technique that aims to make it harder for attackers to injection libio vtables and functions pointers after exploiting a memory corruption vulnerability. However, some old i386 applications do supply their own vtables, so the validation needs to be disabled, and the original implementation did not do this for interposed stdio handles. Consequence: Some old applications would fail with an error message, `Fatal error: glibc detected an invalid stdio handle`. Fix: glibc now detects interposition of stdio handle data structures and disables vtable validation in that case. Result: Old applications which were impacted by this defect work again.
Clone Of: 1595191
Last Closed: 2019-06-04 17:15:54 UTC
Target Upstream Version:

Attachments (Terms of Use)

System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2019:1338 0 None None None 2019-06-04 17:15:55 UTC
Sourceware 23236 0 'P2' 'RESOLVED' 'Harden function pointers in _IO_str_fields' 2019-12-03 11:42:00 UTC
Sourceware 23313 0 'P2' 'RESOLVED' 'libio vtables validation and standard file object interposition' 2019-12-03 11:42:01 UTC

Description RAD team bot copy to z-stream 2019-05-03 07:48:05 UTC
This bug has been copied from bug #1595191 and has been proposed to be backported to 7.6 z-stream (EUS).

Comment 4 Sergey Kolosov 2019-05-17 11:17:43 UTC
Verified by upstream testsuite tests: libio/tst-vtables-interposed, libio/tst-vtables. Also verified with reproducer on x86_64 https://bugzilla.redhat.com/show_bug.cgi?id=1595191#c1

Comment 6 errata-xmlrpc 2019-06-04 17:15:54 UTC
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.


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