Bug 1662842

Summary: glibc: realloc ncopies integer overflow [rhel-7]
Product: Red Hat Enterprise Linux 7 Reporter: Florian Weimer <fweimer>
Component: glibcAssignee: DJ Delorie <dj>
Status: CLOSED ERRATA QA Contact: Sergey Kolosov <skolosov>
Severity: urgent Docs Contact:
Priority: urgent    
Version: 7.6CC: ashankar, codonell, dj, fweimer, hannsj_uhl, mcermak, mnewsome, pfrankli
Target Milestone: rcKeywords: Patch
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: glibc-2.17-287.el7 Doc Type: No Doc Update
Doc Text:
Story Points: ---
Clone Of: 1662841 Environment:
Last Closed: 2019-08-06 12:49:40 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 1662841    
Bug Blocks: 1655768, 1657582    

Description Florian Weimer 2019-01-02 07:44:51 UTC 
+++ This bug was initially created as a clone of Bug #1662841 +++

Under rare circumstances, the realloc implementation in glibc may not copy the entire allocation.  We need to backport this upstream commit:

commit b50dd3bc8cbb1efe85399b03d7e6c0310c2ead84
Author: Florian Weimer <fw.de>
Date:   Mon Dec 31 22:04:36 2018 +0100

    malloc: Always call memcpy in _int_realloc [BZ #24027]
    
    This commit removes the custom memcpy implementation from _int_realloc
    for small chunk sizes.  The ncopies variable has the wrong type, and
    an integer wraparound could cause the existing code to copy too few
    elements (leaving the new memory region mostly uninitialized).
    Therefore, removing this code fixes bug 24027.
Comment 8 errata-xmlrpc 2019-08-06 12:49:40 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.

https://access.redhat.com/errata/RHSA-2019:2118