[PATCH 5.15 207/356] dmaengine: idxd: Fix possible Use-After-Free in irq_process_work_list

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

5.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Li RongQing <lirongqing@baidu.com>

[ Upstream commit e3215deca4520773cd2b155bed164c12365149a7 ]

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: 16e19e11228b ("dmaengine: idxd: Fix list corruption in description completion")
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20240603012444.11902-1-lirongqing@baidu.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/dma/idxd/irq.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/idxd/irq.c b/drivers/dma/idxd/irq.c
index 6d6af0dc3c0ec..1296076ea217c 100644
--- a/drivers/dma/idxd/irq.c
+++ b/drivers/dma/idxd/irq.c
@@ -233,11 +233,13 @@ 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)) {
 			complete_desc(desc, IDXD_COMPLETE_ABORT);
 			continue;
-- 
2.43.0