scsi: qla2xxx: Fix FCE trace use-after-free during firmware dump

In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Fix FCE trace use-after-free during firmware dump qla2x00_free_fce_trace() freed and cleared ha->fce while holding only fce_mutex. The firmware-dump consumers qla27xx_fwdt_entry_t264() and qla25xx_copy_fce() read ha->fce (NULL check followed by a copy of the buffer) under hardware_lock and never take fce_mutex. A debugfs FCE disable could therefore free the DMA buffer between a dump's NULL check and its copy, resulting in a use-after-free. Unpublish ha->fce under hardware_lock, then release the lock and free the DMA buffer (dma_free_coherent() may sleep). A concurrent dump either completes its check and copy with the buffer still valid, or observes ha->fce == NULL and skips it.

Where it's fixed