dmaengine: idxd: Fix possible Use-After-Free in irq_process_work_list

Use list_for_each_entry_safe() to allow iterating through the list and
deleting the entry in the iteration process. The descriptor is freed via
idxd_desc_complete() and there's a slight chance may cause issue for
the list iterator when the descriptor is reused by another thread
without it being deleted from the list.

Fixes: 16e19e1 ("dmaengine: idxd: Fix list corruption in description completion")
Signed-off-by: Li RongQing <[email protected]>
Reviewed-by: Dave Jiang <[email protected]>
Reviewed-by: Fenghua Yu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Vinod Koul <[email protected]>

Author: lrq-max

drivers/dma/idxd/irq.c

@@ -611,11 +611,13 @@ static void irq_process_work_list(struct idxd_irq_entry *irq_entry)
 
 	spin_unlock(&irq_entry->list_lock);
 
-	list_for_each_entry(desc, &flist, list) {
+	list_for_each_entry_safe(desc, n, &flist, list) {
 		/*
 		 * Check against the original status as ABORT is software defined
 		 * and 0xff, which DSA_COMP_STATUS_MASK can mask out.
 		 */
+		list_del(&desc->list);
+
 		if (unlikely(desc->completion->status == IDXD_COMP_DESC_ABORT)) {
 			idxd_desc_complete(desc, IDXD_COMPLETE_ABORT, true);
 			continue;