Cisco Bug: CSCun71762 - 100-Continue handshake causes KDB
Jun 21, 2020
- Cisco Videoscape Distribution Suite for Television
- Cisco TV Streamer Application
- Cisco Visual Quality Experience (VQE) Channel Provisioning Tools
- Cisco Visual Quality Experience Application
Known Affected Releases
Symptom: Recorder crashes when archiving recorded content, and either reboots with a core file generated, or traps into kernel debugger. Conditions: The recorder uses an HTTP PUT verb to initiate sending data to an archive. The HTTP PUT semantics allows for the client (recorder) to send an "Expect: 100-Continue" header as part of the initial HTTP PUT send by the recorder to server (archive). When using the 100-Continue handshake, the recorder will then wait to start sending the data for the PUT until the archive sends back a 100-Continue message. This 100-Continue handshake gives the archive an opportunity to reject the PUT request before the client starts blasting data. Without using the 100-Continue handshake, the recorder will just start blasting data to the archive immediately after sending the initial HTTP PUT. The 100-Continue handshake is new code in the 3.4.2 branch. This new code has a window of opportunity where if the 100-Continue response from the archive shows up is close proximity of time to a 10 second timeout after having sent the PUT request, the recorder can attempt to dereference a NULL pointer.
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Bug Details Include
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