[TS-4935] Adding same element twice in a row damages DLL's structure silently

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Fix Version/s: 7.1.0
• Component/s: Core
• Backport to Version: 6.2.1, 7.0.0
• Assignee: Gancho Tenev
• Reporter: Gancho Tenev
• Created: 05/Oct/16 13:24
• Updated: 05/Oct/16 22:57

Description

If the DLL list (lib/ts/List.h) is used improperly its internal structure gets damaged silently without any indication to the caller (no assert or return code).

If the the same element is added twice in a row the element's “next” would start pointing to the element itself and all the existing list content would be lost. All further additions will be OK but the next list traversal will be infinite.

Also noticed that when a new element is added to the list the element’s “prev” is not initialized (not a problem in the most common case but should to be fixed).

Issue Links

• relates to: TS-4916 Http2ConnectionState::restart_streams infinite loop causes deadlock