radix_tree_iter_resume: Fix out of bounds error

The address sanitizer occasionally finds an out of bounds error while
running the test-suite.  It turned out to be a read of the pointer
immediately next to the tree root, but this out of bounds error could
have occurred elsewhere.  This happens because radix_tree_iter_resume()
dereferences 'slot' before checking whether we've come to the end of
the chunk.  We can just delete this line; the value was never used.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>

diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index dcb9a2329e65adc02406344c6f03fa297b8827f1..c1c079ffadcd320b7e28d2e7b8853ed18acc5c49 100644 (file)
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -1685,7 +1685,6 @@ void **radix_tree_iter_resume(void **slot, struct radix_tree_iter *iter)
 
        slot++;
        iter->index = __radix_tree_iter_add(iter, 1);
-       node = rcu_dereference_raw(*slot);
        skip_siblings(&node, slot, iter);
        iter->next_index = iter->index;
        iter->tags = 0;