Bug 1834816

Summary:	glibc: internal_end*ent in nss_compat may clobber errno, hiding ERANGE
Product:	Red Hat Enterprise Linux 7	Reporter:	Florian Weimer <fweimer>
Component:	glibc	Assignee:	Florian Weimer <fweimer>
Status:	CLOSED ERRATA	QA Contact:	qe-baseos-tools-bugs
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	7.8	CC:	ashankar, atikhono, codonell, dj, fweimer, mnewsome, pfrankli, sipoyare, skolosov, vmukhame
Target Milestone:	rc	Keywords:	Patch
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	glibc-2.17-317.el7	Doc Type:	Bug Fix
Doc Text:	Cause: The nss_compat module overwrites the errno status with other spurious error codes during processing of password and group entries. Consequence: Password and group lookups can fail because the expected buffer resizing does not happen. Fix: nss_compat avoids overwriting critical errno values with other status codes during password and group lookups. Result: Resizing of the response buffer for password and group lookups works, and lookups suceed as expected.	Story Points:	---
Clone Of:
Clones:	1836867 (view as bug list)		Environment:
Last Closed:	2020-09-29 19:20:26 UTC	Type:	Bug
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:
Bug Blocks:	1402403, 1782203, 1838037

Description Florian Weimer 2020-05-12 13:25:15 UTC

The end*ent functions such as internal_endpwent call into the rest of glibc and other NSS modules, without saving errno around those calls. Since successful function calls can clobber errno, a critical ERANGE error can be masked, and the caller will not retry with a larger buffer, reporting a different error instead.

Comment 7 Sergey Kolosov 2020-06-27 13:08:25 UTC

Verified, the bug has been fixed in glibc-2.17-317.el7

Comment 9 errata-xmlrpc 2020-09-29 19:20:26 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 (Low: glibc security, bug fix, and enhancement update), 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-2020:3861