Re: [gentoo-user] Maybe bug? (glibc related?)

[lee]

Elias Diem <lists@×××××××××.ch> writes:

> Hi lee
>
> On 2015-12-29, lee wrote:
>
>> Elias Diem <lists@×××××××××.ch> writes:
>>
>> > Hi
>> >
>> > I just got the following while running Vim's testsuite.
>> >
>> > <output>
>> > *** buffer overflow detected ***: vim terminated; report to <http://bugs.gentoo.org/>
>> > Makefile:151: recipe for target 'af.ck' failed
>> > make[2]: *** [af.ck] Killed
>> > </output>
>> >
>> > The compiler gave me the following warning.
>> >
>> > [...]
>> > /usr/include/bits/string3.h:110:3: warning: call to __builtin___strcpy_chk will always overflow destination buffer
>> >    return __builtin___strcpy_chk (__dest, __src, __bos (__dest));
>> >
>> > [...]
>> >
>> > Should I file a bug?
>>
>> The test was successful because the buffer overflow was detected?
>
> I think I don't quite understand your question.
>
> `make test` failed. Therefore I'd say the test was not
> successful.
>
> I run a hardened profile. I guess that's why the overflow
> was detected and vim terminated.

When you perform a strcpy() and overflow the destination buffer, you are
supposed to experience a segmentation fault.  It shouldn't matter
whether you run a hardened profile or not for detecting these.

I imagine it was discovered that a segmentation fault did occur, and
that it inevitably would occur --- since gcc tells you that one will
occur when using __builtin___strcpy_chk() --- and the application was
terminated.  Otherwise, the test would have been unsuccessful.

Whether this is a bug or not depends on what you're supposed to expect,
which I don't know.  If someone would run the test suite on a
non-hardened profile and got the same warning from gcc, but vim wouldn't
be terminated when the segmentation fault occurs, then I'd be worried.