[
https://issues.apache.org/jira/browse/GUACAMOLE-720?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16753042#comment-16753042
]
Nick Couchman commented on GUACAMOLE-720:
-----------------------------------------
Thanks, [~scaronni]. We'll definitely look into it. I wonder if this will be
resolved by GUACAMOLE-637 - I'm not certain, but I know that Mike is working on
some changes to the versions of strn* functions being used. See the following
PR: https://github.com/apache/guacamole-server/pull/209.
> 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: Minor
>
> 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)
