power: sequencing: pcie-m2: fix serdev controller reference leak

In pwrseq_pcie_m2_create_serdev_one(), if serdev_ctrl->serdev is NULL but
pdev is already tracked in ctx->pci_devices, we return early from the
loop and skip the serdev_controller_put(), leaking the reference.

Initialize ret to 0 and jump directly to the label that ensures the
reference is released.

Cc: stable@vger.kernel.org
Closes: https://sashiko.dev/#/bug/linux-07754192-a8ad-42d6-ab1b-cd6f16bec846
Fixes: c4be520907a4 ("power: sequencing: pcie-m2: Create serdev for PCI devices present before probe")
Link: https://patch.msgid.link/20261105-pwrseq-pcie-m2-serdev-ref-leak-v1-1-e2e022ca17ec@oss.qualcomm.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

1 files changed, 4 insertions, 6 deletions

diff --git a/drivers/power/sequencing/pwrseq-pcie-m2.c b/drivers/power/sequencing/pwrseq-pcie-m2.c
index 4f283af8b014..35a995c7ec17 100644
--- a/drivers/power/sequencing/pwrseq-pcie-m2.c
+++ b/drivers/power/sequencing/pwrseq-pcie-m2.c
@@ -296,7 +296,7 @@ static int pwrseq_pcie_m2_create_serdev_one(struct pwrseq_pcie_m2_ctx *ctx,
 	struct serdev_controller *serdev_ctrl;
 	struct device *dev = ctx->dev;
 	struct pwrseq_pci_dev *pci_dev;
-	int ret;
+	int ret = 0;
 
 	struct device_node *serdev_parent __free(device_node) =
 		of_graph_get_remote_node(dev_of_node(ctx->dev), 3, 0);
@@ -308,16 +308,14 @@ static int pwrseq_pcie_m2_create_serdev_one(struct pwrseq_pcie_m2_ctx *ctx,
 		return 0;
 
 	/* Bail out if the device was already attached to this controller */
-	if (serdev_ctrl->serdev) {
-		serdev_controller_put(serdev_ctrl);
-		return 0;
-	}
+	if (serdev_ctrl->serdev)
+		goto err_put_ctrl;
 
 	/* Bail out if the serdev device was already created for the PCI dev */
 	scoped_guard(mutex, &ctx->list_lock) {
 		list_for_each_entry(pci_dev, &ctx->pci_devices, list) {
 			if (pci_dev->pdev == pdev)
-				return 0;
+				goto err_put_ctrl;
 		}
 	}