Thread: another ecpg crash
Hi,
I found another bug when using 'exec sql include filename'. If you use a
filename that doesn't exist, ecpg crashes while trying to close a null
pointer. The above test case shows it. A possible fix is attached.
#include <stdio.h>
/* foo.h doesn't exist */
exec sql include foo;
int main(void)
{
return 0;
}
(gdb) bt
#0 0xb7a746fd in fclose@@GLIBC_2.1 () from /lib/libc.so.6
#1 0x080496e1 in mmerror (error_code=2, type=ET_FATAL, error=0xb7eeb0cc
<Address 0xb7eeb0cc out of bounds>)
at /a/pgsql/dev/pgsql/src/interfaces/ecpg/preproc/preproc.y:93
#2 0x08069d07 in parse_include () at
/a/pgsql/dev/pgsql/src/interfaces/ecpg/preproc/pgc.l:1270
#3 0x08067fa7 in base_yylex () at
/a/pgsql/dev/pgsql/src/interfaces/ecpg/preproc/pgc.l:1080
#4 0x0806d4ce in filtered_base_yylex () at
/a/pgsql/dev/pgsql/src/interfaces/ecpg/preproc/parser.c:64
#5 0x0804a8a8 in base_yyparse () at y.tab.c:20322
#6 0x0806ca35 in main (argc=2, argv=0xbff0ea94) at
/a/pgsql/dev/pgsql/src/interfaces/ecpg/preproc/ecpg.c:462
(gdb) print yyin
$1 = (FILE *) 0x0
--
Euler Taveira de Oliveira
http://www.timbira.com/
*** ./src/interfaces/ecpg/preproc/preproc.y.orig 2008-05-11 01:28:52.000000000 -0300
--- ./src/interfaces/ecpg/preproc/preproc.y 2008-05-11 01:43:24.000000000 -0300
***************
*** 90,96 ****
ret_value = error_code;
break;
case ET_FATAL:
! fclose(yyin);
fclose(yyout);
if (unlink(output_filename) != 0 && *output_filename != '-')
fprintf(stderr, _("could not remove output file \"%s\"\n"), output_filename);
--- 90,98 ----
ret_value = error_code;
break;
case ET_FATAL:
! /* there are some cases (i.e. file not found) that the input is not available */
! if (!yyin)
! fclose(yyin);
fclose(yyout);
if (unlink(output_filename) != 0 && *output_filename != '-')
fprintf(stderr, _("could not remove output file \"%s\"\n"), output_filename);
Euler Taveira de Oliveira wrote:
> Hi,
>
> I found another bug when using 'exec sql include filename'. If you use a
> filename that doesn't exist, ecpg crashes while trying to close a null
> pointer. The above test case shows it. A possible fix is attached.
Huh, isn't the test backwards?
> --- 90,98 ----
> ret_value = error_code;
> break;
> case ET_FATAL:
> ! /* there are some cases (i.e. file not found) that the input is not available */
> ! if (!yyin)
> ! fclose(yyin);
> fclose(yyout);
> if (unlink(output_filename) != 0 && *output_filename != '-')
> fprintf(stderr, _("could not remove output file \"%s\"\n"), output_filename);
--
Alvaro Herrera http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support
Alvaro Herrera wrote: > Huh, isn't the test backwards? > In which way? I use a simple one but whatever test that uses 'exec sql include foo' and foo.h doesn't exist, it will crash. -- Euler Taveira de Oliveira http://www.timbira.com/
On Sun, May 11, 2008 at 02:19:05AM -0300, Euler Taveira de Oliveira wrote: > Alvaro Herrera wrote: > > >Huh, isn't the test backwards? > > > In which way? I use a simple one but whatever test that uses 'exec sql > include foo' and foo.h doesn't exist, it will crash. I think he means specifically this line in the diff: > ! /* there are some cases (i.e. file not found) > ! * that the input is not available */ > ! if (!yyin) > ! fclose(yyin); This will close the file *only* if yyin is NULL, which probably isn't what is meant. Have a nice day, -- Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/ > Please line up in a tree and maintain the heap invariant while > boarding. Thank you for flying nlogn airlines.
Martijn van Oosterhout wrote: > This will close the file *only* if yyin is NULL, which probably isn't > what is meant. > Ops... you're right. :-) -- Euler Taveira de Oliveira http://www.timbira.com/
On Sun, May 11, 2008 at 01:50:22AM -0300, Euler Taveira de Oliveira wrote: > I found another bug when using 'exec sql include filename'. If you use a > filename that doesn't exist, ecpg crashes while trying to close a null > pointer. The above test case shows it. A possible fix is attached. Thanks again, I just committed the fix. Michael -- Michael Meskes Email: Michael at Fam-Meskes dot De, Michael at Meskes dot (De|Com|Net|Org) ICQ: 179140304, AIM/Yahoo: michaelmeskes, Jabber: meskes@jabber.org Go VfL Borussia! Go SF 49ers! Use Debian GNU/Linux! Use PostgreSQL!