Bug 2217726
| Summary: | Concurrent DELETE and PROPFIND breaks PROPFIND | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 9 | Reporter: | Hisanobu Okuda <hokuda> |
| Component: | httpd | Assignee: | Luboš Uhliarik <luhliari> |
| Status: | CLOSED ERRATA | QA Contact: | Branislav Náter <bnater> |
| Severity: | unspecified | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 9.2 | CC: | jorton, luhliari, mschwabe |
| Target Milestone: | rc | Keywords: | AutoVerified, Triaged |
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | httpd-2.4.57-5.el9 | Doc Type: | If docs needed, set a value |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2023-11-07 08:30:29 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
Thanks for the detailed report! The problem is the stat() here is failing after reading the directory. https://github.com/apache/httpd/blob/66254273e22a5b4051d15d7423b86a5d884b4ee5/modules/dav/fs/repos.c#L1613 We might be able to skip aborting the connection in the case of an ENOENT error here which seems reasonably harmless. Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (Moderate: httpd and mod_http2 security, bug fix, and enhancement update), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHSA-2023:6403 |
Description of problem: Concurrent DELETE and PROPFIND breaks PROPFIND. When executing DELETE and PROPFIND at the same time, PROPFIND may return an empty response. Version-Release number of selected component (if applicable): httpd-2.4.53-11.el9_2.5.x86_64 How reproducible: Steps to Reproduce: 1. provide a container and install httpd: $ sudo subscription-manager register --force --username <red hat customer portal account name> $ podman rm -f rhel9test $ podman login registry.redhat.io $ podman run -it --privileged --cap-add=SYS_PTRACE --name rhel9test registry.redhat.io/ubi9/ubi # dnf install -y --enablerepo rhel-9-for-x86_64-appstream-rpms gdb httpd iproute procps-ng vim # dnf debuginfo-install -y glibc httpd 2. create config files: # vim /etc/httpd/conf.d/dav.conf DavLockDB /var/www/davlock/db Alias /dav /var/www/dav <Directory /var/www/dav> LogLevel trace8 Dav On DirectoryIndex disabled </Directory> # vim /etc/httpd/conf.d/mpm.conf ServerLimit 4 StartServers 1 MinSpareThreads 1 MaxSpareThreads 4 ThreadsPerChild 4 MaxRequestWorkers 1000 3. create dav contents: # mkdir /var/www/dav # mkdir /var/www/davlock # chmod 777 /var/www/dav /var/www/davlock # for i in x y z; do touch /var/www/dav/$i; chown apache:apache /var/www/dav/$i; done 4. start httpd: # nohup /usr/sbin/httpd -DFOREGROUND & 5. attach gdb: # ps -ef | grep httpd # gdb -p <largest PID of httpd processes> 6. set break points: (gdb) b unlink (gdb) b lstat 7. run PROPFIND on another shell: $ podman exec -it rhel9test /bin/bash curl "http://localhost/dav/" -X PROPFIND -i -H 'Depth:1' -d '<?xml version="1.0" encoding="utf-8"?><D:propfind xmlns:D="DAV:"><D:allprop/></D:propfind>' 8. run DELETE on another shell: $ podman exec -it rhel9test /bin/bash curl -v "http://localhost/dav/z" -X DELETE 9. enter 'c' to gdb prompt several times: (gdb) c (gdb) c (gdb) c (gdb) c (gdb) c (gdb) c (gdb) c (gdb) c (gdb) c Then, you can observe the empty response and the error message in error_log: # curl "http://localhost/dav/" -X PROPFIND -i -H 'Depth:1' -d '<?xml version="1.0" encoding="utf-8"?><D:propfind xmlns:D="DAV:"><D:allprop/></D:propfind>' curl: (52) Empty reply from server error_log: [Wed Jun 07 08:04:32.922724 2023] [dav:error] [pid 354:tid 380] [client ::1:46944] Provider encountered an error while streaming a multistatus PROPFIND response. [404, #0] Actual results: Expected results: Additional info: