pds_core: fix use-after-free on workqueue during remove

Overview

In the Linux kernel, the following vulnerability has been resolved:

pds_core: fix use-after-free on workqueue during remove

In pdsc_remove(), the workqueue is destroyed before pdsc_teardown() is called. This ordering allows two paths to queue work on the destroyed workqueue:

1. If pdsc_teardown() -> pdsc_devcmd_reset() times out, the error path in pdsc_devcmd_locked() queues health_work.

2. A NotifyQ event can trigger the ISR and queue work before free_irq() is called in pdsc_teardown().

Fix by moving destroy_workqueue() after pdsc_teardown() so the workqueue outlives every queuer; destroy_workqueue() then flushes any work still pending.

Draining the queued work also requires ordering the teardown so the resources that work touches are freed last:

• In pdsc_qcq_free(), after freeing the interrupt, cancel_work_sync() the queue's work and only then clear qcq->intx, so pdsc_process_adminq()'s read of qcq->intx for interrupt-credit return cannot race with the clear.

• Free adminqcq before notifyqcq: the shared adminq ISR is released when adminqcq is freed, and the adminq work accesses notifyqcq, so both must be stopped before notifyqcq is freed.

Affected

• Linux >= 01ba61b55b2041a39c54aefb3153c770dd59a0ef < bac237c2aedb8225bfd2317c1361bbfce1e419ca
• Linux >= 01ba61b55b2041a39c54aefb3153c770dd59a0ef < 224214eb4182ff20a665b615a90b66017539dd75
• Linux >= 01ba61b55b2041a39c54aefb3153c770dd59a0ef < 9e0f80fac50ab95dd75537c8ecaf5051d01f19b5
• Linux >= 01ba61b55b2041a39c54aefb3153c770dd59a0ef < ecc7a7d7569ec1d6a61e18372696b9de97635156
• Linux >= 01ba61b55b2041a39c54aefb3153c770dd59a0ef < 0ad134881508c36b65c1a8864f8bec53adbd3327
• Linux 6.4

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.