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.

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.

kernel-devel-7.2.8-1.1 on GA media

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 126 more

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.