[GUACAMOLE-1259] Son of immediate double-free upon connecting to Windows RDP

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.3.0
• Fix Version/s: 1.4.0
• Component/s: RDP
• Assignee: Mike Jumper
• Reporter: Mike Jumper
• Created: 10/Jan/21 05:13
• Updated: 08/Apr/21 18:40
• Resolved: 11/Jan/21 07:43

Description

From GUACAMOLE-1241:

Regression testing against staging/1.3.0 using the Docker image, I am seeing an immediate disconnect due to a double-free when attempting to connect to Windows RDP:

...
guacd[24698]: INFO:	Loading keymap "base"
guacd[24698]: INFO:	Loading keymap "en-us-qwerty"
guacd[24698]: INFO:	Connected to RDPDR 1.13 as client 0x0005
free(): double free detected in tcache 2
guacd[6]: INFO:	Connection "$e6955582-c6f2-4912-a4bd-a3ffee002cd1" removed.

With there being a few memory-related RDP changes in the upcoming release (and with no such issues in 1.2.0), I suspect this is a regression.

This is still happening when building against FreeRDP 2.0.0-rc4, not because things are incorrectly detected at build time, but because the config.h header containing the macro resulting from that detection is not included in the relevant file. The call to Stream_Free() therefore always occurs, even if FreeRDP was detected as doing this automatically.

Issue Links

• is caused by: GUACAMOLE-1181 Memory allocated for outbound SVC PDUs may not be freed
• is duplicated by: GUACAMOLE-1324 Guacamole v1.3.0 RDP Sessions disconnects after seconds after upgrading from v1.2.0
• relates to: GUACAMOLE-1241 Immediate double-free upon connecting to Windows RDP