[bug report] Potential atomicity bug in drivers/target/sbp/sbp_target.c, between tgt_agent_fetch_work() and tgt_agent_rw_orb_pointer()

Dear Linux kernel maintainers,

My research-based static analyzer found a potential atomicity bug
within the 'drivers/target/sbp' subsystem, more specifically, in
'drivers/target/sbp/sbp_target.c'.

This potential issue is present as of git commit
eb3f4b7426cfd2b79d65b7d37155480b32259a11 of the mainline kernel.

Potential concurrent triggering executions:
T0:
tgt_agent_fetch_work
     --> spin_lock_bh(&agent->lock);
     --> agent->doorbell = false;
     --> agent->orb_pointer = next_orb;
     --> spin_unlock_bh(&agent->lock)

T1:
tgt_agent_rw_orb_pointer
    --> spin_unlock_bh(&agent->lock);
    --> agent->orb_pointer = sbp2_pointer_to_addr(ptr);
    --> agent->doorbell = false;

The writes to 'agent->orb_pointer' and 'agent->doorbell' are outside
of the critical section of 'agent->lock'.
This does align with the lock's critical section in T0 as
'agent->lock' seems to be responsible for 'agent->orb_pointer'.

Please kindly check at your convenience. Thank you for your time and
consideration.

Best regards,
Ginger