Bug 2062648

Summary: libcap: Incorrect use of prctl in various functions
Product: Red Hat Enterprise Linux 8 Reporter: Florian Weimer <fweimer>
Component: libcapAssignee: Anderson Sasaki <ansasaki>
Status: CLOSED ERRATA QA Contact: Martin Zelený <mzeleny>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 8.6CC: mzeleny, rsroka
Target Milestone: rcKeywords: Triaged
Target Release: ---Flags: pm-rhel: mirror+
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: libcap-2.48-3.el8 Doc Type: No Doc Update
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2022-11-08 10:48:38 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:

Description Florian Weimer 2022-03-10 10:08:13 UTC
cap_proc.c contains this:

268	int cap_get_bound(cap_value_t cap)
269	{
270	    int result;
271	
272	    result = prctl(PR_CAPBSET_READ, pr_arg(cap), pr_arg(0));
273	    if (result < 0) {
274		errno = -result;
275		return -1;
276	    }
277	    return result;
278	}

However, prctl is the glibc wrapper here, and it returns -1 on failure and sets errno.  As a result, all errors are reported as EPERM (which is 1).

I found this while looking at bug 2061727, but it s actually unrelated to it. It just confuses debugging because EPERM does not show up in strace.

Comment 6 errata-xmlrpc 2022-11-08 10:48:38 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 (libcap 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/RHBA-2022:7722