Wireshark-dev: Re: [Wireshark-dev] [Bug 7775] Wireshark leaks memory when selecting packets

From: Evan Huus <eapache@xxxxxxxxx>
Date: Mon, 8 Oct 2012 16:29:15 -0400
On Mon, Oct 8, 2012 at 3:31 PM, Jakub Zawadzki
<darkjames-ws@xxxxxxxxxxxx> wrote:
> Hi Evan,
>
> On Mon, Oct 08, 2012 at 03:06:29PM -0400, Evan Huus wrote:
>> On Mon, Oct 8, 2012 at 2:58 PM,  <bugzilla-daemon@xxxxxxxxxxxxx> wrote:
>> > https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=7775
>> >
>> > --- Comment #10 from Anatoly <aries.nah@xxxxxxxxx> 2012-10-08 14:58:26 EDT ---
>> > I've tried r45395, nothin is changed except wireshark has crashed:)
>> > But I got one more probably interesting fact: r45380 (w/o your fixes) on Vista
>> > 32 bit - memory consumption increases slightly and sometimes it decreases, but
>> > the same revision of XP 32bit - it always increases by ~2MB.
>>
>> This appears to be an XP-specific bug if anyone still has an XP
>> install to test with (I don't).
>
> It mighe be OOM, for every packet we mmap 10MiB chunk of memory.
> Which is *not* unmaped in emem_free_all() nor ep_free_pool().
> (AFAIR for performance reasons)
>
> Generally it'd be best to save somewhere mem->free_list before
> 1333         g_free(mem);
>
> If it's hard to do than emem_destroy_chunk() is your friend.
>
> [PS: I haven't test it yet, but looking at diff it makes sense,
>      if not please move on ;)]

I think you're right - I did all of my testing of the emem changes
under the valgrind-wireshark.sh script, which disables chunks (and
thus the mmap) so I never noticed it before. I have a patch (attached)
which I believe ought to correctly share the free_list between the
various pools, but for some reason I can't seem to track down it's
causing random canary errors.

Any ideas?

Thanks,
Evan

Attachment: share-free-list.patch
Description: Binary data