Messages in this thread | | | From | frowand.list@gmail ... | Subject | [PATCH v3 0/2] of: phandle_cache, fix refcounts, remove stale entry | Date | Tue, 18 Dec 2018 11:40:01 -0800 |
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From: Frank Rowand <frank.rowand@sony.com>
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@sony.com>
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