curl / Mailing Lists / curl-library / Single Mail
Buy commercial curl support from WolfSSL. We help you work out your issues, debug your libcurl applications, use the API, port to new platforms, add new features and more. With a team lead by the curl founder himself.

Re: Crash when libcurl invokes prune_dead_connections

From: Henrik Holst via curl-library <curl-library_at_lists.haxx.se>
Date: Tue, 8 Feb 2022 15:52:35 +0100

From what you submit it looks like data->state.conn_cache is NULL (or
pointing to recently freed memory). I would recommend that you run your
application under valgrind and try to trigger the error and see what
valgrind finds. If this is a use after free, valgrind will point out where
it was freed which would give a better indication on where the problem lies.

/HH

Den tis 8 feb. 2022 kl 13:10 skrev Marius via curl-library <
curl-library_at_lists.haxx.se>:

> Hello everyone,
>
> Some time ago I have developed a small C application which uses
> libcurl to send data to some APIs. (It's very basic)
>
> Since about mid-December my application started to crash when invoking
> libcurl.
>
> After doing some debugging it looks like the prune_dead_connections call
> tries to access some freed memory when doing: Curl_timediff[1].
>
> My application the multi interface to libcurl and libevent2 events.
> A link to the project is here[2].
>
> I have a dump of the crash[3], from a binary compiled against libevent2
> version 2.1.12, and libcurl version curl+7_81_0-1.
>
> Unfortunately I am not sure if the problem is with curl or, more
> likely, I had a bug in my integration with it that got exposed by an
> update.
>
> If anyone can give me any suggestions about how to investigate this
> better, I would appreciate it. Also please let me know what other
> type of information I need to provide for others to make sense of
> this issue.
>
> Thank you,
> /Marius Orcsik
>
> [1]
>
> https://github.com/curl/curl/blob/2610142139d14265ed9acf9ed83cdf73d6bb4d05/lib/url.c#L1084
> [2] https://github.com/mariusor/mpris-scrobbler
> [3] https://habarnam.ro/mpris-scrobbler.dump.tgz
> --
> Unsubscribe: https://lists.haxx.se/listinfo/curl-library
> Etiquette: https://curl.haxx.se/mail/etiquette.html
>


-- 
Unsubscribe: https://lists.haxx.se/listinfo/curl-library
Etiquette:   https://curl.haxx.se/mail/etiquette.html
Received on 2022-02-08