gai_cancel()

[Phil Blundell]

On Fri, 2017-06-16 at 17:52 +0200, Florian Weimer wrote:
> On 06/16/2017 05:46 PM, Phil Blundell wrote:
> > Opinions?
> 
> Is this related to bug 20874?
> 
> Â  https://sourceware.org/bugzilla/show_bug.cgi?id=20874
> 

No, I don't think it's related.  I poked at that bug a bit and I am
fairly sure that the problem there is specifically in gai_suspend(). 
Under conditions that I don't entirely understand yet, we seem to be
somehow returning from gai_suspend while its waitlist[] entry is still
linked into requestlist->waiting.  Since gai_suspend() allocated its
waitlist[] on the stack, this leads rapidly to disaster when gai_notify
subsequently tries to traverse the linked list.

p.