GNU bug report logs - #19567
"segmentation fault" for long patterns ...

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Roméo Capulet <p-pioneer-q <at> gmx.fr>
To: bug-grep <at> gnu.org
Subject: "segmentation fault" for long patterns ...
Date: Sun, 11 Jan 2015 17:28:37 +0100

[Message part 1 (text/plain, inline)]

hi

I got a segmentation fault when I try to match a very long pattern on a 
file:
$ grep -Po 'jQuery\.extend\(Drupal\.settings,[ 
\t]*\{((?!\}\}\)).)+\}\}\);' /tmp/pattern-exemple.txt
Erreur de segmentation


the grep version : grep (GNU grep) 2.16


the gdb backtrace:
#0  0xb7f7d01a in ?? () from /lib/i386-linux-gnu/libpcre.so.3
#1  0xb7f8b090 in ?? () from /lib/i386-linux-gnu/libpcre.so.3
#2  0xb7f8b3e3 in ?? () from /lib/i386-linux-gnu/libpcre.so.3
#3  0xb7f8b090 in ?? () from /lib/i386-linux-gnu/libpcre.so.3
#4  0xb7f8b3e3 in ?? () from /lib/i386-linux-gnu/libpcre.so.3
(...)
#13099 0xb7f8b090 in ?? () from /lib/i386-linux-gnu/libpcre.so.3
#13100 0xb7f88ab3 in ?? () from /lib/i386-linux-gnu/libpcre.so.3
#13101 0xb7f8e9f3 in pcre_exec () from /lib/i386-linux-gnu/libpcre.so.3
#13102 0x0804c8a2 in ?? ()
#13103 0x0804e191 in ?? ()
#13104 0x0804f3de in ?? ()
#13105 0x0804a630 in ?? ()
#13106 0xb7dc7905 in __libc_start_main (main=0x804a150, argc=4, 
ubp_av=0xbffff8a4, init=0x806bfd0, fini=0x806c040, rtld_fini=0xb7fed5f0 
<_dl_fini>, stack_end=0xbffff89c) at libc-start.c:260
#13107 0x0804b16d in ?? ()

[pattern-exemple.txt (text/plain, attachment)]

Message #10 received at 19567-done <at> debbugs.gnu.org (full text, mbox):

From: Jim Meyering <jim <at> meyering.net>
To: Roméo Capulet <p-pioneer-q <at> gmx.fr>
Cc: 19567-done <at> debbugs.gnu.org
Subject: Re: bug#19567: "segmentation fault" for long patterns ...
Date: Sun, 11 Jan 2015 09:25:00 -0800

On Sun, Jan 11, 2015 at 8:28 AM, Roméo Capulet <p-pioneer-q <at> gmx.fr> wrote:
> I got a segmentation fault when I try to match a very long pattern on a
> file:
> $ grep -Po 'jQuery\.extend\(Drupal\.settings,[ \t]*\{((?!\}\}\)).)+\}\}\);'
> /tmp/pattern-exemple.txt
> Erreur de segmentation
>
> the grep version : grep (GNU grep) 2.16

Thank you for the complete bug report.
That appears to be due to a bug in the version of libpcre that your
version of grep uses.
Using the latest release, grep-2.21 with newer pcre, that example no
longer causes trouble.

Since this issue appears not to affect the latest version, I'm marking
this ticket as "done".

Message #13 received at 19567 <at> debbugs.gnu.org (full text, mbox):

From: Norihiro Tanaka <noritnk <at> kcn.ne.jp>
To: Romeo Capulet <p-pioneer-q <at> gmx.fr>
Cc: 19567 <at> debbugs.gnu.org
Subject: Re: bug#19567: "segmentation fault" for long patterns ...
Date: Mon, 12 Jan 2015 09:53:59 +0900

On Sun, 11 Jan 2015 17:28:37 +0100
Romeo Capulet <p-pioneer-q <at> gmx.fr> wrote:

> hi
> 
> I got a segmentation fault when I try to match a very long pattern on a file:
> $ grep -Po 'jQuery\.extend\(Drupal\.settings,[ \t]*\{((?!\}\}\)).)+\}\}\);' /tmp/pattern-exemple.txt
> Erreur de segmentation
> 
> 
> the grep version : grep (GNU grep) 2.16
> 
> 
> the gdb backtrace:
> #0  0xb7f7d01a in ?? () from /lib/i386-linux-gnu/libpcre.so.3
> #1  0xb7f8b090 in ?? () from /lib/i386-linux-gnu/libpcre.so.3
> #2  0xb7f8b3e3 in ?? () from /lib/i386-linux-gnu/libpcre.so.3
> #3  0xb7f8b090 in ?? () from /lib/i386-linux-gnu/libpcre.so.3
> #4  0xb7f8b3e3 in ?? () from /lib/i386-linux-gnu/libpcre.so.3
> (...)
> #13099 0xb7f8b090 in ?? () from /lib/i386-linux-gnu/libpcre.so.3
> #13100 0xb7f88ab3 in ?? () from /lib/i386-linux-gnu/libpcre.so.3
> #13101 0xb7f8e9f3 in pcre_exec () from /lib/i386-linux-gnu/libpcre.so.3
> #13102 0x0804c8a2 in ?? ()
> #13103 0x0804e191 in ?? ()
> #13104 0x0804f3de in ?? ()
> #13105 0x0804a630 in ?? ()
> #13106 0xb7dc7905 in __libc_start_main (main=0x804a150, argc=4,
> ubp_av=0xbffff8a4, init=0x806bfd0, fini=0x806c040,
> rtld_fini=0xb7fed5f0 <_dl_fini>, stack_end=0xbffff89c) at libc-start.c:260
> #13107 0x0804b16d in ?? ()
> 

Perhaps, this bug may be duplication of bug#19420.  If we search a
pattern with "?!" for a long line, we can cause stack overflow.

Can you avoid the bug by increasing of stack size?

Message #16 received at 19567 <at> debbugs.gnu.org (full text, mbox):

From: Roméo Capulet <p-pioneer-q <at> gmx.fr>
To: 19567 <at> debbugs.gnu.org
Subject: Re: bug#19567: closed (Re: bug#19567: "segmentation fault" for long
 patterns ...)
Date: Mon, 12 Jan 2015 07:32:09 +0100

Le 11/01/2015 18:26, GNU bug Tracking System a écrit :
> Your bug report
>
> #19567: "segmentation fault" for long patterns ...
>
> which was filed against the grep package, has been closed.
>
> The explanation is attached below, along with your original report.
> If you require more details, please reply to 19567 <at> debbugs.gnu.org.
>
Ok so i've downloaded, compiled and installed grep-2.21 and pcre2-10.00 
and the bug does not occur any more so seem to be fixed.

thanks.

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