Processing out-of-order commands or finishing commands based on invalid
server responses resulted in inconsistent analyzer state, potentially
triggering null pointer references for crafted traffic.
This commit reworks cf9fe91705 such that
too many pending commands are simply discarded, rather than any attempt
being made to process them. Further, invalid server responses do not
result in command completion anymore.
Test PCAP was crafted based on traffic produced by the OSS-Fuzz reproducer.
Closes#215
The cmds list may grow unbounded due to the POP3 analyzer being in
multiLine mode after seeing `AUTH` in a Redis connection, but never
a `.` terminator. This can easily be provoked by the Redis ping
command.
This adds two heuristics: 1) Forcefully process the oldest commands in
the cmds list and cap it at max_pending_commands. 2) Start raising
analyzer violations if the client has been using more than
max_unknown_client_commands commands (default 10).
Closes#3936
