[TS-1007] SSN Close called before TXN Close

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.1
• Fix Version/s: 6.2.0
• Component/s: TS API
• Labels: incompatible
• Assignee: Susan Hinrichs
• Reporter: Nick Kew
• Created: 01/Nov/11 11:34
• Updated: 15/Jun/16 15:29
• Resolved: 16/Apr/16 16:23

Description

Where a plugin implements both SSN_CLOSE_HOOK and TXN_CLOSE_HOOK, the SSN_CLOSE_HOOK is called first of the two. This messes up normal cleanups!

Details:
Register a SSN_START event globally
In the SSN START, add a TXN_START and a SSN_CLOSE
In the TXN START, add a TXN_CLOSE

Stepping through, I see the order of events actually called, for the simple case of a one-off HTTP request with no keepalive:

SSN_START
TXN_START
SSN_END
TXN_END

Whoops, SSN_END cleaned up the SSN context, leaving dangling pointers in the TXN!

Issue Links

• breaks: TS-3804 ASAN heap-use-after-free in HttpClientSession::destroy
• breaks: TS-3805 ASAN heap-use-after-free in ProxyClientSession::ssn_hook_get
• is related to: TS-4507 It is still possible for SSN_CLOSE hook to be called before TXN_CLOSE hook
• relates to: TS-3612 Restructure Proxy Client Sessions to support transaction oriented Sessions execute transaction hooks and connection oriented Sessions execute session hooks