target/linux/generic/backport-5.15/808-v6.2-0013-nvmem-core-fix-device-node-refcounting.patch

   1 From edcf2fb660526b5ed29f93bd17328a2b4835c8b2 Mon Sep 17 00:00:00 2001
   2 From: Michael Walle <michael@walle.cc>
   3 Date: Fri, 27 Jan 2023 10:40:12 +0000
   4 Subject: [PATCH] nvmem: core: fix device node refcounting
   5
   6 In of_nvmem_cell_get(), of_get_next_parent() is used on cell_np. This
   7 will decrement the refcount on cell_np, but cell_np is still used later
   8 in the code. Use of_get_parent() instead and of_node_put() in the
   9 appropriate places.
  10
  11 Fixes: 69aba7948cbe ("nvmem: Add a simple NVMEM framework for consumers")
  12 Fixes: 7ae6478b304b ("nvmem: core: rework nvmem cell instance creation")
  13 Cc: stable@vger.kernel.org
  14 Signed-off-by: Michael Walle <michael@walle.cc>
  15 Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
  16 Link: https://lore.kernel.org/r/20230127104015.23839-8-srinivas.kandagatla@linaro.org
  17 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  18 ---
  19  drivers/nvmem/core.c | 11 ++++++++---
  20  1 file changed, 8 insertions(+), 3 deletions(-)
  21
  22 --- a/drivers/nvmem/core.c
  23 +++ b/drivers/nvmem/core.c
  24 @@ -1237,16 +1237,21 @@ struct nvmem_cell *of_nvmem_cell_get(str
  25         if (!cell_np)
  26                 return ERR_PTR(-ENOENT);
  27
  28 -       nvmem_np = of_get_next_parent(cell_np);
  29 -       if (!nvmem_np)
  30 +       nvmem_np = of_get_parent(cell_np);
  31 +       if (!nvmem_np) {
  32 +               of_node_put(cell_np);
  33                 return ERR_PTR(-EINVAL);
  34 +       }
  35
  36         nvmem = __nvmem_device_get(nvmem_np, device_match_of_node);
  37         of_node_put(nvmem_np);
  38 -       if (IS_ERR(nvmem))
  39 +       if (IS_ERR(nvmem)) {
  40 +               of_node_put(cell_np);
  41                 return ERR_CAST(nvmem);
  42 +       }
  43
  44         cell_entry = nvmem_find_cell_entry_by_node(nvmem, cell_np);
  45 +       of_node_put(cell_np);
  46         if (!cell_entry) {
  47                 __nvmem_device_put(nvmem);
  48                 return ERR_PTR(-ENOENT);