[ gpsdrive-Bugs-3457119 ] friendsd.c: 2 * bad strncpy

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Bugs item #3457119, was opened at 2011-12-11 03:31
Message generated for change (Comment added) made by hbowman
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Category: source code
Group: gpsdrive-2.11
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: dcb (dcb314)
Assigned to: Nobody/Anonymous (nobody)
Summary: friendsd.c: 2 * bad strncpy

Initial Comment:
I just tried to compile gpsdrive-2.11 with compiler flag -D_FORTIFY_SOURCE=2.

It noticed

1. 

In function 'strncpy',
    inlined from 'dg_echo' at /home/dcb/rpmbuild/BUILD/gpsdrive-2.11/src/friendsd.c:229:16:
/usr/include/bits/string3.h:121:3: warning: call to __builtin___strncpy_chk will always overflow destination buffer [enabled by default]

The source code is

                            strncpy ((list +
                                  i)->txt,
                                 mesg,
                                 MAXMESG - 1);

Suggest new code
                            strncpy ((list +
                                  i)->txt,
                                 mesg,
                                 1024);

2.

In function 'strncpy',
    inlined from 'dg_echo' at /home/dcb/rpmbuild/BUILD/gpsdrive-2.11/src/friendsd.c:245:15:
/usr/include/bits/string3.h:121:3: warning: call to __builtin___strncpy_chk will always overflow destination buffer [enabled by default]

Source code is

                        strncpy ((list + i)->txt,
                             mesg, MAXMESG - 1);

Suggest new code

                        strncpy ((list + i)->txt,
                             mesg, 1024);




----------------------------------------------------------------------

>Comment By: Hamish B (hbowman)
Date: 2011-12-11 05:02

Message:
how about this solution:

Index: src/friendsd.c
===================================================================
--- src/friendsd.c	(revision 2597)
+++ src/friendsd.c	(working copy)
@@ -170,7 +170,7 @@
 struct
 {
 	char id[31];
-	char txt[1024];
+	char txt[MAXMESG];
 	long int times;
 } *list;
 

?,
Hamish

----------------------------------------------------------------------

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