[PATCH v8 net 0/6] netem: bug fixes

[Stephen Hemminger <stephen@networkplumber.org>]

These bugs were found when doing AI-assisted review of sch_netem.c
during investigation of the packet duplication recursion problem
addressed in Jamal's series.

The fixes cover:

 - probability gaps in the 4-state Markov loss model
 - queue limit not accounting for reordered packets
 - PRNG reseeded on every tc change, breaking reproducibility
 - slot configuration not validated (inverted ranges, negative
   delays, negative limits)
 - slot delay arithmetic overflow for ranges above ~2.1 seconds
 - negative latency and jitter wrapping to huge time_to_send
   values via u64 arithmetic

v8 - added check for negative TCA_NETEM_LATENCY64 and TCA_NETEM_JITTER64
   - extended slot validation to cover dist_delay, dist_jitter,
     max_packets and max_bytes

Stephen Hemminger (6):
  net/sched: netem: fix probability gaps in 4-state loss model
  net/sched: netem: fix queue limit check to include reordered packets
  net/sched: netem: only reseed PRNG when seed is explicitly provided
  net/sched: netem: validate slot configuration
  net/sched: netem: fix slot delay calculation overflow
  net/sched: netem: check for negative latency and jitter

 net/sched/sch_netem.c | 76 ++++++++++++++++++++++++++++++++++++-------
 1 file changed, 64 insertions(+), 12 deletions(-)

-- 
2.53.0