Bug 1226400

Summary:	nwfilter_dhcpsnoop.c:1962: 2 * off by one error ?
Product:	[Community] Virtualization Tools	Reporter:	David Binderman <dcb314>
Component:	libvirt	Assignee:	Erik Skultety <eskultet>
Status:	CLOSED NEXTRELEASE	QA Contact:
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	unspecified	CC:	eskultet, rbalakri
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Last Closed:	2015-06-02 12:08:56 UTC	Type:	Bug
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
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Description David Binderman 2015-05-29 16:25:31 UTC

Description of problem:

[nwfilter/nwfilter_dhcpsnoop.c:1962]: (error) Width 16 given in format string (no. 3) is larger than destination buffer 'ipstr[16]', use %15s to prevent overflowing it.

[nwfilter/nwfilter_dhcpsnoop.c:1962]: (error) Width 16 given in format string (no. 4) is larger than destination buffer 'srvstr[16]', use %15s to prevent overflowing it.

Source code is

        if (sscanf(line, "%u %55s %16s %16s", &ipl.timeout,
                   ifkey, ipstr, srvstr) < 4) {




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Comment 1 Erik Skultety 2015-06-02 12:02:55 UTC

Fixed in:

commit 152e315433f2ff69a5e91a2269812918da2ce091
Author: Erik Skultety <eskultet>
Date:   Tue Jun 2 09:25:04 2015 +0200

    nwfilter: Fix sscanf off-by-one error in virNWFilterSnoopLeaseFileLoad
    
    We allocate 16 bytes for IPv4 address and 55 bytes for interface
    key, therefore we should read up to 15/54 bytes and let the last byte
    reserved for terminating null byte in sscanf.

v1.2.16-11-g152e315