Re: [PATCH net] net/sched: sch_teql: move rcu_read_lock()/spin_lock() from _bh variants

[Paolo Abeni <pabeni@redhat.com>]

On 6/30/26 5:09 PM, Jamal Hadi Salim wrote:
> This is a followup based on sashiko comments [1] on commit e5b811fe7931
> ("net/sched: sch_teql: Introduce slaves_lock to avoid race condition and UAF")
> 
> Use plain rcu_read_lock()/spin_lock() in teql_master_xmit() instead of the
> _bh variants, since ndo_start_xmit is already invoked with BH disabled
> by the core stack and the _bh primitives can warn in_hardirq() when xmit
> is reached through netpoll or a softirq xmit path with hard IRQs disabled.
> 
> Moves rcu_read_lock() after restart: label + adds rcu_read_unlock() before
> goto restart (fixes the unbounded RCU hold across retries)
> 
> [1] https://sashiko.dev/#/patchset/20260628111229.669751-1-jhs%40mojatatu.com

I'm adding a formal:

Fixes: commit e5b811fe7931 ("net/sched: sch_teql: Introduce slaves_lock to avoid race condition and UAF")

to try to avoid backports of the latter without this one.

/P