FAILED: patch "[PATCH] mmc: hsq: Fix use-after-free in retry work" failed to apply to 6.1-stable tree

The patch below does not apply to the 6.1-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-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 5d132990475f02cfa1debe03d50b479432864ebd
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026092256-daytime-musty-b7f1@gregkh' --subject-prefix 'PATCH 6.1.y' 'HEAD^..'

Possible dependencies:

thanks,

greg k-h

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

From 5d132990475f02cfa1debe03d50b479432864ebd Mon Sep 17 00:00:00 2001
From: Fan Wu <[email protected]>
Date: Fri, 14 Aug 2026 08:23:54 +0000
Subject: [PATCH] mmc: hsq: Fix use-after-free in retry work

mmc_hsq_pump_requests() queues retry_work when request_atomic() returns -EBUSY; today sdhci-sprd is the only consumer that implements request_atomic(). The work is embedded in a devm-allocated mmc_hsq, but is never cancelled during driver removal. Work still pending at unbind can therefore run after the devm allocation has been released and dereference hsq->mmc and hsq->mrq.

Use devm_work_autocancel() to cancel and drain retry_work before the devm allocation is released. By the time devres cleanup begins, mmc_remove_host() has already stopped the host, so no new requests can arm the work.

This issue was found by an in-house static analysis tool.

index 79836705c176..57e172bd3487 100644
@@ -7,6 +7,7 @@
  * Author: Baolin Wang <[email protected]>
  */
 
+#include <linux/devm-helpers.h>
 #include <linux/mmc/card.h>
 #include <linux/mmc/host.h>
 #include <linux/module.h>

@@ -345,6 +346,7 @@ static const struct mmc_cqe_ops mmc_hsq_ops = {
 
 int mmc_hsq_init(struct mmc_hsq *hsq, struct mmc_host *mmc)
 {
+	int ret;
 	int i;
 	hsq->num_slots = HSQ_NUM_SLOTS;
 	hsq->next_tag = HSQ_INVALID_TAG;

@@ -363,7 +365,11 @@ int mmc_hsq_init(struct mmc_hsq *hsq, struct mmc_host *mmc)
 	for (i = 0; i < HSQ_NUM_SLOTS; i++)
 		hsq->tag_slot[i] = HSQ_INVALID_TAG;
 
-	INIT_WORK(&hsq->retry_work, mmc_hsq_retry_handler);
+	ret = devm_work_autocancel(mmc_dev(mmc), &hsq->retry_work,
+				   mmc_hsq_retry_handler);
+	if (ret)
+		return ret;
+
 	spin_lock_init(&hsq->lock);
 	init_waitqueue_head(&hsq->wait_queue);
 

From: Fan Wu <[email protected]>

[ Upstream commit 5d132990475f02cfa1debe03d50b479432864ebd ]

mmc_hsq_pump_requests() queues retry_work when request_atomic() returns -EBUSY; today sdhci-sprd is the only consumer that implements request_atomic(). The work is embedded in a devm-allocated mmc_hsq, but is never cancelled during driver removal. Work still pending at unbind can therefore run after the devm allocation has been released and dereference hsq->mmc and hsq->mrq.

Use devm_work_autocancel() to cancel and drain retry_work before the devm allocation is released. By the time devres cleanup begins, mmc_remove_host() has already stopped the host, so no new requests can arm the work.

This issue was found by an in-house static analysis tool.

---
 drivers/mmc/host/mmc_hsq.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

index 9d35453e7371b..929cdb496cdd7 100644
@@ -7,6 +7,7 @@
  * Author: Baolin Wang <[email protected]>
  */
 
+#include <linux/devm-helpers.h>
 #include <linux/mmc/card.h>
 #include <linux/mmc/host.h>
 #include <linux/module.h>

@@ -339,6 +340,8 @@ static const struct mmc_cqe_ops mmc_hsq_ops = {
 
 int mmc_hsq_init(struct mmc_hsq *hsq, struct mmc_host *mmc)
 {
+	int ret;
+
 	hsq->num_slots = HSQ_NUM_SLOTS;
 	hsq->next_tag = HSQ_INVALID_TAG;
 

@@ -351,7 +354,11 @@ int mmc_hsq_init(struct mmc_hsq *hsq, struct mmc_host *mmc)
 	hsq->mmc->cqe_private = hsq;
 	mmc->cqe_ops = &mmc_hsq_ops;
 
-	INIT_WORK(&hsq->retry_work, mmc_hsq_retry_handler);
+	ret = devm_work_autocancel(mmc_dev(mmc), &hsq->retry_work,
+				   mmc_hsq_retry_handler);
+	if (ret)
+		return ret;
+
 	spin_lock_init(&hsq->lock);
 	init_waitqueue_head(&hsq->wait_queue);
 

2.53.0