Re: [PATCH v2] powerpc: kernel: fix refcount leak in format_show()

[Hangyu Hua]

Any further suggestions for this patch? guys.

Thanks.

On 2022/3/2 10:19, Hangyu Hua wrote:

Refcount leak will happen when format_show returns failure in multiple
cases. Unified management of of_node_put can fix this problem.

Signed-off-by: Hangyu Hua <hbh...@gmail.com>
---

v2:
1. change the title and description information.
2. fix all possible refcount leak.

  arch/powerpc/kernel/secvar-sysfs.c | 9 ++++++---
  1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/secvar-sysfs.c 
b/arch/powerpc/kernel/secvar-sysfs.c
index a0a78aba2083..1ee4640a2641 100644
--- a/arch/powerpc/kernel/secvar-sysfs.c
+++ b/arch/powerpc/kernel/secvar-sysfs.c
@@ -26,15 +26,18 @@ static ssize_t format_show(struct kobject *kobj, struct 
kobj_attribute *attr,
        const char *format;

node = of_find_compatible_node(NULL, NULL, "ibm,secvar-backend");

-       if (!of_device_is_available(node))
-               return -ENODEV;
+       if (!of_device_is_available(node)) {
+               rc = -ENODEV;
+               goto out;
+       }

rc = of_property_read_string(node, "format", &format);

        if (rc)
-               return rc;
+               goto out;

rc = sprintf(buf, "%s\n", format); +out:

        of_node_put(node);

return rc;