[nico@ngolde.de: some code issues]

[nico@ngolde.de: some code issues]

[Richard Stallman]

Would someone please fix these in Emacs 22, then ack?

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Date: Sat, 5 Jan 2008 18:59:08 +0100
From: Nico Golde <nico@ngolde.de>
To: bug-gnu-emacs@gnu.org
Message-ID: <20080105175908.GA31673@ngolde.de>
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Subject: some code issues


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Hi,
I had a quick look at the pop.c code today and found some=20
issues.

In pop_stat:

365   if (strncmp (fromserver, "+OK ", 4))
366     {
367       if (0 =3D=3D strncmp (fromserver, "-ERR", 4))
368    {
369      strncpy (pop_error, fromserver, ERROR_MAX);
370    }
371      else
372    {
373      strcpy (pop_error,
374    >=B7=B7=B7  "Unexpected response from POP server in pop_stat");
375      pop_trash (server);
376    }
377       return (-1);
378     }

380   *count =3D atoi (&fromserver[4]);
381=20
382   fromserver =3D index (&fromserver[4], ' ');
383   if (! fromserver)
384     {
385       strcpy (pop_error,
386 >=B7=B7=B7      "Badly formatted response from server in pop_stat");
387       pop_trash (server);
388       return (-1);
389     }

If I don't miss anything the atoi call in 380 is not save as it is not=20
save because it is not ensure that &fromserver[4] is not NULL. A crafted
pop3 server could thus crash emacs. This is of course not a real issue but
wouldn't be nice. Same for the pop_last function.

In pop_list:

440=20
441   *IDs =3D (int *) malloc ((how_many + 1) * sizeof (int));
442   *sizes =3D (int *) malloc ((how_many + 1) * sizeof (int));
443   if (! (*IDs && *sizes))
444     {
445       strcpy (pop_error, "Out of memory in pop_list");
446       return (-1);
447     }
448=20

in 441 and 442 there should be some check for how_many to prevent an integer
overflow here.
Same problem for the xnew macro in etags.c

What do you think about this?
Kind regards
Nico
- --=20
Nico Golde - http://www.ngolde.de - nion@jabber.ccc.de - GPG: 0x73647CFF
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Re: [nico@ngolde.de: some code issues]

[Chong Yidong]

> In pop_stat:
> If I don't miss anything the atoi call in 380 is not save as it is not
> save because it is not ensure that &fromserver[4] is not NULL. A crafted
> pop3 server could thus crash emacs. This is of course not a real issue but
> wouldn't be nice. Same for the pop_last function.
>
> In pop_list:
> in 441 and 442 there should be some check for how_many to prevent an integer
> overflow here.

Fixed, thanks.

> Same problem for the xnew macro in etags.c

I don't think this is a problem considering how xnew is called. Unless
you can point out a specific problem.

Re: [nico@ngolde.de: some code issues]

[Chong Yidong]

> I had a quick look at the pop.c code today and found some
> issues.
>
> In pop_stat:
>
> If I don't miss anything the atoi call in 380 is not save as it is not
> save because it is not ensure that &fromserver[4] is not NULL. A crafted
> pop3 server could thus crash emacs. This is of course not a real issue but
> wouldn't be nice. Same for the pop_last function.
>
> In pop_list:
>
> in 441 and 442 there should be some check for how_many to prevent an integer
> overflow here.

Fixed.  Thanks for pointing these out.

> Same problem for the xnew macro in etags.c

I don't think this is a problem, considering the way the xnew macro is
called in etags.c --- unless you can point to a specific problem.

Re: [nico@ngolde.de: some code issues]

[Nico Golde]

[-- Attachment #1.1: Type: text/plain, Size: 870 bytes --]

Hi Chong,
* Chong Yidong <cyd@stupidchicken.com> [2008-01-10 16:29]:
> > I had a quick look at the pop.c code today and found some
> > issues.
> >
> > In pop_stat:
> >
> > If I don't miss anything the atoi call in 380 is not save as it is not
> > save because it is not ensure that &fromserver[4] is not NULL. A crafted
> > pop3 server could thus crash emacs. This is of course not a real issue but
> > wouldn't be nice. Same for the pop_last function.
> >
> > In pop_list:
> >
> > in 441 and 442 there should be some check for how_many to prevent an integer
> > overflow here.
> 
> Fixed.  Thanks for pointing these out.

What do you think about requesting a CVE id for this?

Kind regards
Nico
-- 
Nico Golde - http://www.ngolde.de - nion@jabber.ccc.de - GPG: 0x73647CFF
For security reasons, all text in this mail is double-rot13 encrypted.

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