Uploaded image for project: 'ZABBIX BUGS AND ISSUES'
  1. ZABBIX BUGS AND ISSUES
  2. ZBX-15685

zabbix_sender may report successful sending of data while actually there is an error

    Details

    • Type: Incident report
    • Status: Open
    • Priority: Trivial
    • Resolution: Unresolved
    • Affects Version/s: 3.0.25, 4.0.5rc1
    • Fix Version/s: None
    • Component/s: Agent (G)
    • Environment:
      GNU/Linux
    • Story Points:
      1

      Description

      If Zabbix server or proxy closes connection during TLS handshake then zabbix_sender may receive SIGPIPE signal.
      Although there is a signal handler in data sending thread of zabbix_sender the SIGPIPE is not handled.
      zabbix_sender returns 0 (success), but server/proxy has accepted no data at all.

      This issue was noticed when working on support of LibreSSL and OpenSSL with no PSK.

      Steps to reproduce:

      1. Compile OpenSSL 1.1.1a with no PSK support.
      2. Compile Zabbix server to work with this special OpenSSL. As changes are not yet merged you need to take svn://svn.zabbix.com/branches/dev/ZBX-15552-30 branch which can handle OpenSSL with no PSK support.
      3. Run server with this special OpenSSL.
      4. Run standard zabbix_sender from a machine where zabbix_sender uses usual OpenSSL 1.1.1a (with PSK support enabled). Use connecting with PSK.
      5. Run zabbix_sender multiple times. Results are varying from time to time:
        $ zabbix_sender -z 192.168.1.2 -s "host1" --tls-connect psk --tls-psk-identity=testid --tls-psk-file=/home/andris/zabbix_agentd.psk -k trapper_test -o abc
        Sending failed. Use option -vv for more detailed output.
        $ zabbix_sender -z 192.168.1.2 -s "host1" --tls-connect psk --tls-psk-identity=testid --tls-psk-file=/home/andris/zabbix_agentd.psk -k trapper_test -o abc
        sent: 1; skipped: 0; total: 1
        

      Expected:
      zabbix_sender always reports error.

      Could be OpenSSL-specific. It works as expected if zabbix sender uses GnuTLS 3.6.6. Also works if zabbix_sender sends to proxy which uses LibreSSL 2.8.2 (no PSK support).

        Attachments

          Activity

            People

            • Assignee:
              zabbix.dev Zabbix Development Team
              Reporter:
              andris Andris Mednis
            • Votes:
              0 Vote for this issue
              Watchers:
              2 Start watching this issue

              Dates

              • Created:
                Updated: