firmware: arm_scpi: Fix device_node reference leak in probe path

A device_node reference obtained from the device tree is not released
on all error paths in the arm_scpi probe path. Specifically, a node
returned by of_parse_phandle() could be leaked when the probe failed
after the node was acquired. The probe function returns early and
the shmem reference is not released.

Use __free(device_node) scope-based cleanup to automatically release
the reference when the variable goes out of scope.

Fixes: ed7ecb883901 ("firmware: arm_scpi: Add compatibility checks for shmem node")
Signed-off-by: Felix Gu <ustc.gu@gmail.com>
Message-Id: <20260121-arm_scpi_2-v2-1-702d7fa84acb@gmail.com>
Signed-off-by: Sudeep Holla <sudeep.holla@kernel.org>

diff --git a/drivers/firmware/arm_scpi.c b/drivers/firmware/arm_scpi.c
index 00e74449ce09e5c012f52fd5b575ebfaa2f6e102..2acad5fa5a2867bccbfaa381510325b503071704 100644 (file)
--- a/drivers/firmware/arm_scpi.c
+++ b/drivers/firmware/arm_scpi.c
@@ -18,6 +18,7 @@
 
 #include <linux/bitmap.h>
 #include <linux/bitfield.h>
+#include <linux/cleanup.h>
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/export.h>
@@ -940,13 +941,13 @@ static int scpi_probe(struct platform_device *pdev)
                int idx = scpi_drvinfo->num_chans;
                struct scpi_chan *pchan = scpi_drvinfo->channels + idx;
                struct mbox_client *cl = &pchan->cl;
-               struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
+               struct device_node *shmem __free(device_node) =
+                       of_parse_phandle(np, "shmem", idx);
 
                if (!of_match_node(shmem_of_match, shmem))
                        return -ENXIO;
 
                ret = of_address_to_resource(shmem, 0, &res);
-               of_node_put(shmem);
                if (ret) {
                        dev_err(dev, "failed to get SCPI payload mem resource\n");
                        return ret;