In the Linux kernel, the following vulnerability has been resolved: scsi: qedi: Fix use after...

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

scsi: qedi: Fix use after free bug in qedi_remove()

In qedi_probe() we call __qedi_probe() which initializes &qedi->recovery_work with qedi_recovery_handler() and &qedi->board_disable_work with qedi_board_disable_work().

When qedi_schedule_recovery_handler() is called, schedule_delayed_work() will finally start the work.

In qedi_remove(), which is called to remove the driver, the following sequence may be observed:

Fix this by finishing the work before cleanup in qedi_remove().

CPU0 CPU1

                 |qedi_recovery_handler

qedi_remove | __qedi_remove | iscsi_host_free | scsi_host_put | //free shost | |iscsi_host_for_each_session |//use qedi->shost

Cancel recovery_work and board_disable_work in __qedi_remove().