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authorMatthew Wilcox <willy@infradead.org>2018-08-18 07:05:50 -0400
committerMatthew Wilcox <willy@infradead.org>2018-08-21 23:49:31 -0400
commit76f070b4135563165c523ab560056b7a9353e2f2 (patch)
tree7b4d6288ab637779a59d325f1cc1acaca8b904f9
parentd1c0d5e3c63d61226a75f24d5c35fe20755f0180 (diff)
downloadlinux-76f070b4135563165c523ab560056b7a9353e2f2.tar.bz2
radix-tree: Fix UBSAN warning
get_slot_offset() can be called with a NULL 'parent' argument. In this case, the calculated value will not be used, but calculating it is undefined. Rather than fixing the caller (__radix_tree_delete) to not call get_slot_offset(), make get_slot_offset() robust against being called with a NULL parent. Signed-off-by: Matthew Wilcox <willy@infradead.org>
-rw-r--r--lib/radix-tree.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index a9e41aed6de4..cc6096b97afb 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -120,7 +120,7 @@ bool is_sibling_entry(const struct radix_tree_node *parent, void *node)
static inline unsigned long
get_slot_offset(const struct radix_tree_node *parent, void __rcu **slot)
{
- return slot - parent->slots;
+ return parent ? slot - parent->slots : 0;
}
static unsigned int radix_tree_descend(const struct radix_tree_node *parent,