[PATCH v3 0/2] of: phandle_cache, fix refcounts, remove stale entry

[frowand . list]

From: Frank Rowand <frank.rowand@xxxxxxxx>

Non-overlay dynamic devicetree node removal may leave the node in
the phandle cache.  Subsequent calls to of_find_node_by_phandle()
will incorrectly find the stale entry.  This bug exposed the foloowing
phandle cache refcount bug.

The refcount of phandle_cache entries is not incremented while in
the cache, allowing use after free error after kfree() of the
cached entry.

Changes since v2:
  - patch 2/2: add temporary variable np in __of_free_phandle_cache_entry()
    to improve readability
  - patch 2/2: explain reason for WARN_ON() in comment
  - patch 2/2: add Fixes tag in patch comment

Changes since v1:
  - make __of_free_phandle_cache() static
  - add WARN_ON(1) for unexpected condition in of_find_node_by_phandle()
  
Frank Rowand (2):
  of: of_node_get()/of_node_put() nodes held in phandle cache
  of: __of_detach_node() - remove node from phandle cache

 drivers/of/base.c       | 101 ++++++++++++++++++++++++++++++++++++------------
 drivers/of/dynamic.c    |   3 ++
 drivers/of/of_private.h |   4 ++
 3 files changed, 83 insertions(+), 25 deletions(-)

-- 
Frank Rowand <frank.rowand@xxxxxxxx>