FAILED: patch "[PATCH] scsi: qla2xxx: Quiesce response IRQ before freeing request" failed to apply to 5.15-stable tree

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 505753ec2594c6af09a601f0dd60be7d840c1d2d
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026090925-anointer-haggler-c959@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..'

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 505753ec2594c6af09a601f0dd60be7d840c1d2d Mon Sep 17 00:00:00 2001
From: Nilesh Javali <[email protected]>
Date: Thu, 30 Jul 2026 21:28:22 +0530
Subject: [PATCH] scsi: qla2xxx: Quiesce response IRQ before freeing request
queue

qla2xxx_delete_qpair() deletes the request queue before the response queue. qla25xx_delete_req_que() frees the request queue memory (kfree(req) in qla25xx_free_req_que()), but the response-queue MSI-X is only released later, in qla25xx_free_rsp_que(). In that window the response interrupt can still fire, qla2xxx_msix_rsp_q() queues qpair->q_work, and qla_do_work() -> qla24xx_process_response_queue() dereferences the now-freed rsp->req (LOGINOUT/CT/ELS entries and the status path), a use-after-free.

The cancel_work_sync() added for the qpair teardown lives in the response free path, which runs after the request queue is already freed, so it does not protect rsp->req.

Release the response-queue interrupt and flush qpair->q_work before deleting the request queue, so no late completion can reach the freed request queue. Clearing have_irq makes the subsequent qla25xx_free_rsp_que() skip its free_irq(), and the firmware queue-delete order (request then response) is preserved; the request-delete mailbox completes on the default vector and is unaffected by dropping the qpair response interrupt early.

index fed6dbc3b6ae..e6b499245794 100644
@@ -10695,11 +10695,28 @@ int qla2xxx_delete_qpair(struct scsi_qla_host *vha, struct qla_qpair *qpair)
 {
 	int ret = QLA_FUNCTION_FAILED;
 	struct qla_hw_data *ha = qpair->hw;
+	struct rsp_que *rsp = qpair->rsp;
 
 	qpair->delete_in_progress = 1;
 
 	qla_free_buf_pool(qpair);
 
+	/*
+	 * The response-queue interrupt schedules qla_do_work(), which
+	 * dereferences qpair->rsp->req.  Release the interrupt and flush
+	 * any pending work before the request queue is freed below so a
+	 * late completion cannot touch the freed request queue.  The
+	 * firmware queue-delete order (request then response) is kept.
+	 */
+	if (rsp && rsp->msix && rsp->msix->have_irq) {
+		free_irq(rsp->msix->vector, rsp->msix->handle);
+		rsp->msix->have_irq = 0;
+		rsp->msix->in_use = 0;
+		rsp->msix->handle = NULL;
+	}
+	if (rsp && ha->wq)
+		cancel_work_sync(&qpair->q_work);
+
 	ret = qla25xx_delete_req_que(vha, qpair->req);
 	if (ret != QLA_SUCCESS)
 		goto fail;

From: Nilesh Javali <[email protected]>

[ Upstream commit 505753ec2594c6af09a601f0dd60be7d840c1d2d ]

qla2xxx_delete_qpair() deletes the request queue before the response queue. qla25xx_delete_req_que() frees the request queue memory (kfree(req) in qla25xx_free_req_que()), but the response-queue MSI-X is only released later, in qla25xx_free_rsp_que(). In that window the response interrupt can still fire, qla2xxx_msix_rsp_q() queues qpair->q_work, and qla_do_work() -> qla24xx_process_response_queue() dereferences the now-freed rsp->req (LOGINOUT/CT/ELS entries and the status path), a use-after-free.

The cancel_work_sync() added for the qpair teardown lives in the response free path, which runs after the request queue is already freed, so it does not protect rsp->req.

Release the response-queue interrupt and flush qpair->q_work before deleting the request queue, so no late completion can reach the freed request queue. Clearing have_irq makes the subsequent qla25xx_free_rsp_que() skip its free_irq(), and the firmware queue-delete order (request then response) is preserved; the request-delete mailbox completes on the default vector and is unaffected by dropping the qpair response interrupt early.

---
 drivers/scsi/qla2xxx/qla_init.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

index 177b71fae2f89..3804024793c70 100644
@@ -9904,9 +9904,26 @@ int qla2xxx_delete_qpair(struct scsi_qla_host *vha, struct qla_qpair *qpair)
 {
 	int ret = QLA_FUNCTION_FAILED;
 	struct qla_hw_data *ha = qpair->hw;
+	struct rsp_que *rsp = qpair->rsp;
 
 	qpair->delete_in_progress = 1;
 
+	/*
+	 * The response-queue interrupt schedules qla_do_work(), which
+	 * dereferences qpair->rsp->req.  Release the interrupt and flush
+	 * any pending work before the request queue is freed below so a
+	 * late completion cannot touch the freed request queue.  The
+	 * firmware queue-delete order (request then response) is kept.
+	 */
+	if (rsp && rsp->msix && rsp->msix->have_irq) {
+		free_irq(rsp->msix->vector, rsp->msix->handle);
+		rsp->msix->have_irq = 0;
+		rsp->msix->in_use = 0;
+		rsp->msix->handle = NULL;
+	}
+	if (rsp && ha->wq)
+		cancel_work_sync(&qpair->q_work);
+
 	ret = qla25xx_delete_req_que(vha, qpair->req);
 	if (ret != QLA_SUCCESS)
 		goto fail;

2.53.0