[Bug build/15017] New: potential buffer overflow uncovered by compiling with -O3 and FORTIFY_SOURCE

[Bug build/15017] New: potential buffer overflow uncovered by compiling with -O3 and FORTIFY_SOURCE

[matt at use dot net]

http://sourceware.org/bugzilla/show_bug.cgi?id=15017

             Bug #: 15017
           Summary: potential buffer overflow uncovered by compiling with
                    -O3 and FORTIFY_SOURCE
           Product: gdb
           Version: 7.5
            Status: NEW
          Severity: critical
          Priority: P2
         Component: build
        AssignedTo: unassigned@sourceware.org
        ReportedBy: matt@use.net
    Classification: Unclassified


I got this when compiling the latest Fedora source RPM (7.5.1-32). My default
CFLAGS is -O3 instead of the default -O2:

In function 'strncat',
    inlined from 'svr4_create_solib_event_breakpoints' at
../../gdb/solib-svr4.c:2076:
/usr/include/bits/string3.h:152: error: call to __builtin___strncat_chk might
overflow destination buffer


this correctly fails the build. The fix was simple, as the correct use of
strncat for the same data is one line below:
              if (with_prefix)
                strncat (name, "rtld_", sizeof (name));

              strncat (name, probe_info[i].name, sizeof (name) - sizeof
("rtld_"));

becomes

              if (with_prefix)
                strncat (name, "rtld_", sizeof (name) - sizeof("rtld_"));

              strncat (name, probe_info[i].name, sizeof (name) - sizeof
("rtld_"));


and this eliminates the warning/error.

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[Bug build/15017] potential buffer overflow uncovered by compiling with -O3 and FORTIFY_SOURCE

[sergiodj at redhat dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=15017

Sergio Durigan Junior <sergiodj at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |sergiodj at redhat dot com
         Resolution|                            |INVALID

--- Comment #1 from Sergio Durigan Junior <sergiodj at redhat dot com> 2013-01-14 23:04:24 UTC ---
Thanks for the report, but this bug has to be opened against Fedora's GDB. 
Closing as INVALID.  I have contacted the reporter and asked him to do so.

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[Bug build/15017] potential buffer overflow uncovered by compiling with -O3 and FORTIFY_SOURCE

[gbenson at redhat dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=15017

Gary Benson <gbenson at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |gbenson at redhat dot com

--- Comment #2 from Gary Benson <gbenson at redhat dot com> 2013-01-15 13:20:07 UTC ---
I filed this as https://bugzilla.redhat.com/show_bug.cgi?id=895527

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