Wireshark-dev: Re: [Wireshark-dev] New packet list - out of memory?

From: Jeff Morriss <jeff.morriss.ws@xxxxxxxxx>
Date: Thu, 08 Oct 2009 09:58:04 -0400
didier wrote:
But are canaries used at all? In my understanding without
DEBUG_INTENSE_CANARY_CHECKS they are never checked and it's unset by
default.

Erm, emem_free_all() checks that the canaries haven't been corrupted:

 if (memcmp(npc->canary_info->canary[i], canary, npc->canary_info->cmp_len[i]) != 0)
     g_error("Memory corrupted");

I fixed a bug a while ago where a dissector was writing past the end of its se_alloc()'d memory:

https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=1513

I don't think we can/should turn off canaries in se_ allocations. Instead we should create a new canary-less allocator. (Not sure what such a thing should be named, of course...)