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Re: crash seen in multi_socket

From: Kunal Ekawde via curl-library <>
Date: Sun, 12 May 2019 22:17:43 +0530

Thanks Daniel for checking this over weekend.

Ok, I shall try to update to 7.64.1 but that would take sometime to
integrate, sanitize and load run.

A break would be same consequence as continue in this flow I think. The
'continue' fixed trap #1,
which I could reproduce, but using this patch resulted in trap #2. Based on
trap #2 backtrace,
I've update the patch to 'return result;' //CURLM_OK instead of continue. I
m yet to verify the minimal
load run with the server abruptly terminating case, which most likely
resulted in trap #2. Do you think
'result result;' is not correct there ? One thing missing there would be
updating running_handles.
Please let me know if updating running_handles and return CURLM_OK would be
good or if that is
not correct.


On Sun, May 12, 2019 at 2:32 AM Daniel Stenberg <> wrote:

> On Sat, 11 May 2019, Kunal Ekawde via curl-library wrote:
> > I'm using libcurl - 7.64.0 with nghttp2 for http2 call flow. For
> http/1.1
> > this crash is not seen.
> I recommend using 7.64.1!
> > I tried with following fix:
> > /* the socket can be shared by many transfers, iterate */
> > for(e = list->head; e; e = e->next) {
> > data = (struct Curl_easy *)e->ptr;
> > // crash fix - temp
> > if (!data)
> > continue;
> I think this should do a 'break' instead of a 'continue'. After all, this
> happens because the connection died so there is no more transfers on the
> same
> connection.
> > While this would just be defensive fix, the root cause fix could be
> > elsewhere also, request to please check / comment.
> This is a bit tricky to reproduce so I haven't managed to do this myself
> yet.
> I'm just reading your description and the code and thinking.
> If you add the break like this in there, does this fix the problem for
> you?
> Does it have any other flaws? I'm thinking we might want to terminate
> those
> remaining transfers on the same socket in a more immediate way...
> What do you do to reproduce this case?
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Received on 2019-05-12