You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@guacamole.apache.org by "Simone Caronni (JIRA)" <ji...@apache.org> on 2019/01/26 13:31:00 UTC
[jira] [Commented] (GUACAMOLE-720) Build failure with GCC 9
[ https://issues.apache.org/jira/browse/GUACAMOLE-720?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16753038#comment-16753038 ]
Simone Caronni commented on GUACAMOLE-720:
------------------------------------------
Originally reported by Jeff Law for Fedora.
> Build failure with GCC 9
> ------------------------
>
> Key: GUACAMOLE-720
> URL: https://issues.apache.org/jira/browse/GUACAMOLE-720
> Project: Guacamole
> Issue Type: Bug
> Components: guacd
> Affects Versions: 1.0.0
> Reporter: Simone Caronni
> Priority: Major
>
> In particular GCC 9 complains about this code:
> {code}
> > BUILDSTDERR: In file included from /usr/include/string.h:494,
> > BUILDSTDERR: from /usr/include/winpr/collections.h:25,
> > BUILDSTDERR: from /usr/include/freerdp/types.h:80,
> > BUILDSTDERR: from /usr/include/freerdp/svc.h:24,
> > BUILDSTDERR: from /usr/include/freerdp/utils/svc_plugin.h:27,
> > BUILDSTDERR: from ./rdp_svc.h:25,
> > BUILDSTDERR: from guac_svc/svc_service.h:24,
> > BUILDSTDERR: from guac_svc/svc_service.c:22:
> > BUILDSTDERR: In function 'strncpy',
> > BUILDSTDERR: inlined from 'VirtualChannelEntry' at guac_svc/svc_service.c:56:5:
> > BUILDSTDERR: /usr/include/bits/string_fortified.h:106:10: error: '__builtin_strncpy' output may be truncated copying 7 bytes from a string of length 7 [-Werror=stringop-truncation]
> > BUILDSTDERR: 106 | return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
> > BUILDSTDERR: | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > BUILDSTDERR: cc1: all warnings being treated as errors
> {code}
> Which stems from this code:
> {code}
> > /* Init channel def */
> > strncpy(svc_plugin->[plugin.channel_def.name|http://plugin.channel_def.name/], svc->name,
> > GUAC_RDP_SVC_MAX_LENGTH);
> {code}
> The compiler is complaining because it can not prove the resulting string has a proper NUL terminator. This can cause runtime faults and even security issues.
> Most folks are fixing this by either NUL terminating the string after the call to strncpy . However, in some cases the string is not guaranteed to be NUL terminated -- in those cases the "nonstring" attribute is more appropriate. Note that using "nonstring" will cause the compiler to analyze use points and warn if you pass a "nonstring" variable to a routine that expects a properly terminated NUL string such as strlen.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)