Hello Guacamole Community, We are experiencing a crash in guacd in our production environment and would appreciate any insights you might have. The crash appears to be related to the RDP protocol, specifically when loading a Dynamic Virtual Channel (DVC).
*Summary of the Issue:* The guacd process crashes during an RDP connection. The last log message from the crashing process indicates it was attempting to load the disp DVC. The backtrace confirms the crash occurs within the FreeRDP library's drdynvc handling thread. *Logs:* Here is the relevant log snippet from guacd just before it crashed. The process ID is 1432425. plaintext Sep 16 12:47:23 guacd[1432425]: 2025-09-16 12:47:23.368484 guacd[1432425]: DEBUG:#011Loading Dynamic Virtual Channel disp Sep 16 12:47:26 guacd[1565]: 2025-09-16 12:47:26.274395 guacd[1565]: DEBUG:#011shutdown is sent successfully [1432425] *Backtrace:* The backtrace of the crashing thread (LWP 1432468) points directly to drdynvc_virtual_channel_client_thread. plaintext #0 0x00007ff54031da31 in StreamPool_Take () from /opt/zscaler/lib64/libwinpr2.so.2 #1 0x00007ff54041be5c in drdynvc_virtual_channel_client_thread () from /opt/zscaler/lib64/libfreerdp-client2.so.2 #2 0x00007ff54034aa75 in thread_launcher () from /opt/zscaler/lib64/libwinpr2.so.2 #3 0x00007ff544e8a19a in start_thread () from /usr/lib64/libc.so.6 #4 0x00007ff544f0f240 in clone3 () from /usr/lib64/libc.so.6 *Our Analysis:* The crash seems to stem from a bug or race condition within the FreeRDP library (libfreerdp-client2.so.2) when it handles the drdynvc plugin, which is responsible for DVCs like disp. Our guacd is using FreeRDP libraries from a standard path. Has anyone in the community encountered similar crashes with drdynvc? Any suggestions on how to further debug this or potential workarounds would be greatly appreciated. Thank you for your time and help. Thanks, Dilip -- This communication (including any attachments) is intended for the sole use of the intended recipient and may contain confidential, non-public, and/or privileged material. Use, distribution, or reproduction of this communication by unintended recipients is not authorized. If you received this communication in error, please immediately notify the sender and then delete all copies of this communication from your system.
