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Posted to issues@stdcxx.apache.org by "Travis Vitek (JIRA)" <ji...@apache.org> on 2008/07/10 22:36:31 UTC

[jira] Commented: (STDCXX-989) [EDG C++ 3.9] definition of jmp_buf causes buffer overflow

    [ https://issues.apache.org/jira/browse/STDCXX-989?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12612634#action_12612634 ] 

Travis Vitek commented on STDCXX-989:
-------------------------------------

The definition of {{jmp_buf}} in {{/usr/include/bits/setjmp.h}} is

{noformat}
# if __WORDSIZE == 64
typedef long int __jmp_buf[8];
# else
typedef int __jmp_buf[6];
# endif
{noformat}

Should this value be hard-coded, or should there be a config test to determine the correct value at configuration time?

> [EDG C++ 3.9] definition of jmp_buf causes buffer overflow
> ----------------------------------------------------------
>
>                 Key: STDCXX-989
>                 URL: https://issues.apache.org/jira/browse/STDCXX-989
>             Project: C++ Standard Library
>          Issue Type: Bug
>          Components: 18. Language Support
>    Affects Versions: 4.2.x
>         Environment: Linux/EDG C++ 3.9
>            Reporter: Travis Vitek
>             Fix For: 4.2.x
>
>   Original Estimate: 1h
>  Remaining Estimate: 1h
>
> The {{jmp_buf}} definition provided in {{include/ansi/\_csetjmp.h}} is not as large as {{setjmp()}} is expecting. This causes a buffer overflow when running tests that use the test driver ({{rw_test}}), which results in data corruption. If you run the tests with {{--trace}}, you will see that the _clause_ field of the output is always corrupt after the first use.
> The following shows the expected size for us...
> {noformat}
> $ cat u.cpp; eccp u.cpp && ./a.out
> #include <setjmp.h>
> #include <stdio.h>
> int main ()
> {
>     printf ("%u\n", sizeof (jmp_buf));
>     return 0;
> }
> 156
> {noformat}
> The definition of {{jmp_buf}} in {{include/rw/_csetjmp.h}} is a buffer of 8 bytes.

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