[sr-dev] [kamailio/kamailio] http_async_client: fixed crash on curl callback (PR #4020)

<!-- Kamailio Pull Request Template --> <!-- IMPORTANT: - for detailed contributing guidelines, read: https://github.com/kamailio/kamailio/blob/master/.github/CONTRIBUTING.md - pull requests must be done to master branch, unless they are backports of fixes from master branch to a stable branch - backports to stable branches must be done with 'git cherry-pick -x ...' - code is contributed under BSD for core and main components (tm, sl, auth, tls) - code is contributed GPLv2 or a compatible license for the other components - GPL code is contributed with OpenSSL licensing exception --> #### Pre-Submission Checklist <!-- Go over all points below, and after creating the PR, tick all the checkboxes that apply --> <!-- All points should be verified, otherwise, read the CONTRIBUTING guidelines from above--> <!-- If you're unsure about any of these, don't hesitate to ask on sr-dev mailing list --> - [x] Commit message has the format required by CONTRIBUTING guide - [x] Commits are split per component (core, individual modules, libs, utils, ...) - [x] Each component has a single commit (if not, squash them into one commit) - [x] No commits to README files for modules (changes must be done to docbook files in `doc/` subfolder, the README file is autogenerated) #### Type Of Change - [x] Small bug fix (non-breaking change which fixes an issue) - [ ] New feature (non-breaking change which adds new functionality) - [ ] Breaking change (fix or feature that would change existing functionality) #### Checklist: <!-- Go over all points below, and after creating the PR, tick the checkboxes that apply --> - [ ] PR should be backported to stable branches - [x] Tested changes locally - [x] Related to issue #4019 #### Description I assume that the crash #4019 happens, because of an issue in libcurl, namely in the `event_cb` function ([in this line](https://github.com/kamailio/kamailio/blob/master/src/modules/http_asy…) kamailio removes the pointer to the `cell` object (which was attached to this `g->multi` curl descriptor earlier), and the `cell` object memory is released [at this line](https://github.com/kamailio/kamailio/blob/master/src/modules/http_asy…. However, the crash happens when `event_cb` is called when `curl_multi_remove_handle` is called [at this line](https://github.com/kamailio/kamailio/blob/master/src/modules/http_asy…. In this fix `cell` object is retrieved from the corresponding CURL descriptor and then it's compared with the `cell` object passed to this callback. With this change when this issue happens the `cell` object, which is retrieved from the corresponding CURL descriptor, is NULL pointer, because it was removed earlier [in this line](https://github.com/kamailio/kamailio/blob/master/src/modules/http_asy…, so the crash should not appear. However it might be fixed in other way, namely we may not to pass `cell` to the `event_cb` callback and always retrieve it from CURL descriptor. I would appreciate if developers comment that. You can view, comment on, or merge this pull request online at: https://github.com/kamailio/kamailio/pull/4020 -- Commit Summary -- * http_async_client: fixed crash on curl callback -- File Changes -- M src/modules/http_async_client/http_multi.c (18) -- Patch Links -- https://github.com/kamailio/kamailio/pull/4020.patch https://github.com/kamailio/kamailio/pull/4020.diff -- Reply to this email directly or view it on GitHub: https://github.com/kamailio/kamailio/pull/4020 You are receiving this because you are subscribed to this thread. Message ID: <kamailio/kamailio/pull/4020(a)github.com>