FAILED: patch "[PATCH] iommu/qcom: fix device leak on of_xlate()" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

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 <stable@vger.kernel.org>.

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 6a3908ce56e6879920b44ef136252b2f0c954194
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026010520-snowdrop-judgingly-e0c4@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From 6a3908ce56e6879920b44ef136252b2f0c954194 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Mon, 20 Oct 2025 06:53:06 +0200
Subject: [PATCH] iommu/qcom: fix device leak on of_xlate()

Make sure to drop the reference taken to the iommu platform device when
looking up its driver data during of_xlate().

Note that commit e2eae09939a8 ("iommu/qcom: add missing put_device()
call in qcom_iommu_of_xlate()") fixed the leak in a couple of error
paths, but the reference is still leaking on success and late failures.

Fixes: 0ae349a0f33f ("iommu/qcom: Add qcom_iommu")
Cc: stable@vger.kernel.org	# 4.14: e2eae09939a8
Cc: Rob Clark <robin.clark@oss.qualcomm.com>
Cc: Yu Kuai <yukuai3@huawei.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

diff --git a/drivers/iommu/arm/arm-smmu/qcom_iommu.c b/drivers/iommu/arm/arm-smmu/qcom_iommu.c
index 9222a4a48bb3..f69d9276dc55 100644
--- a/drivers/iommu/arm/arm-smmu/qcom_iommu.c
+++ b/drivers/iommu/arm/arm-smmu/qcom_iommu.c
@@ -566,14 +566,14 @@ static int qcom_iommu_of_xlate(struct device *dev,
 
 	qcom_iommu = platform_get_drvdata(iommu_pdev);
 
+	put_device(&iommu_pdev->dev);
+
 	/* make sure the asid specified in dt is valid, so we don't have
 	 * to sanity check this elsewhere:
 	 */
 	if (WARN_ON(asid > qcom_iommu->max_asid) ||
-	    WARN_ON(qcom_iommu->ctxs[asid] == NULL)) {
-		put_device(&iommu_pdev->dev);
+	    WARN_ON(qcom_iommu->ctxs[asid] == NULL))
 		return -EINVAL;
-	}
 
 	if (!dev_iommu_priv_get(dev)) {
 		dev_iommu_priv_set(dev, qcom_iommu);
@@ -582,10 +582,8 @@ static int qcom_iommu_of_xlate(struct device *dev,
 		 * multiple different iommu devices.  Multiple context
 		 * banks are ok, but multiple devices are not:
 		 */
-		if (WARN_ON(qcom_iommu != dev_iommu_priv_get(dev))) {
-			put_device(&iommu_pdev->dev);
+		if (WARN_ON(qcom_iommu != dev_iommu_priv_get(dev)))
 			return -EINVAL;
-		}
 	}
 
 	return iommu_fwspec_add_ids(dev, &asid, 1);