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| author |   Konstantin Khlebnikov <koct9i@gmail.com> | 2016-02-05 15:37:01 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2016-02-05 18:10:40 -0800 |
| commit | 732042821cfa106b3c20b9780e4c60fee9d68900 (patch) | |
| tree | 9e825128f3807b51449536a3301984857db5e412 | |
| parent | MAINTAINERS: trim the file triggers for ABI/API (diff) | |
| download | linux-dev-732042821cfa106b3c20b9780e4c60fee9d68900.tar.xz linux-dev-732042821cfa106b3c20b9780e4c60fee9d68900.zip | |
radix-tree: fix oops after radix_tree_iter_retry
Helper radix_tree_iter_retry() resets next_index to the current index.
In following radix_tree_next_slot current chunk size becomes zero. This
isn't checked and it tries to dereference null pointer in slot.
Tagged iterator is fine because retry happens only at slot 0 where tag
bitmask in iter->tags is filled with single bit.
Fixes: 46437f9a554f ("radix-tree: fix race in gang lookup")
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Jeremiah Mahler <jmmahler@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/radix-tree.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h index 00b17c526c1f..f54be7082207 100644 --- a/include/linux/radix-tree.h +++ b/include/linux/radix-tree.h @@ -400,7 +400,7 @@ void **radix_tree_iter_retry(struct radix_tree_iter *iter) * @iter: pointer to radix tree iterator * Returns: current chunk size */ -static __always_inline unsigned +static __always_inline long radix_tree_chunk_size(struct radix_tree_iter *iter) { return iter->next_index - iter->index; @@ -434,9 +434,9 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags) return slot + offset + 1; } } else { - unsigned size = radix_tree_chunk_size(iter) - 1; + long size = radix_tree_chunk_size(iter); - while (size--) { + while (--size > 0) { slot++; iter->index++; if (likely(*slot)) |