In the Linux kernel, the following vulnerability has been resolved:
RDMA/mana_ib: drain QP references after partial table insertion
mana_table_store_ud_qp() publishes a QP at its send-queue id before
inserting the receive-queue id, dropping the XArray lock between the two
xa_insert_irq() calls. A concurrent completion handler can look up the QP
and take a transient reference. When the second insertion fails, the
rollback erased only the send-queue entry and returned, leaving both the
initial table reference and the transient reference outstanding while RDMA
core frees the QP, causing a use-after-free.
Drain the reference as normal destruction does: drop the initial reference
and wait for qp->free, releasing the QP only after every concurrent lookup
returns its reference.
