nvmem: core: fix device node refcounting

commit edcf2fb660526b5ed29f93bd17328a2b4835c8b2 upstream.

In of_nvmem_cell_get(), of_get_next_parent() is used on cell_np. This
will decrement the refcount on cell_np, but cell_np is still used later
in the code. Use of_get_parent() instead and of_node_put() in the
appropriate places.

Fixes: 0f00205455f5 ("nvmem: Add a simple NVMEM framework for consumers")
Fixes: 13ec7127ad5a ("nvmem: core: rework nvmem cell instance creation")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230127104015.23839-8-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index e92c6f1aadbbeead752bfb85677bff92cc57bc16..cbe5df99db82333bdcb116279c841a8234db985e 100644 (file)
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -1237,16 +1237,21 @@ struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, const char *id)
        if (!cell_np)
                return ERR_PTR(-ENOENT);
 
-       nvmem_np = of_get_next_parent(cell_np);
-       if (!nvmem_np)
+       nvmem_np = of_get_parent(cell_np);
+       if (!nvmem_np) {
+               of_node_put(cell_np);
                return ERR_PTR(-EINVAL);
+       }
 
        nvmem = __nvmem_device_get(nvmem_np, device_match_of_node);
        of_node_put(nvmem_np);
-       if (IS_ERR(nvmem))
+       if (IS_ERR(nvmem)) {
+               of_node_put(cell_np);
                return ERR_CAST(nvmem);
+       }
 
        cell_entry = nvmem_find_cell_entry_by_node(nvmem, cell_np);
+       of_node_put(cell_np);
        if (!cell_entry) {
                __nvmem_device_put(nvmem);
                return ERR_PTR(-ENOENT);