+ radix-tree-fix-oops-after-radix_tree_iter_retry.patch added to -mm tree

The patch titled
     Subject: radix-tree: fix oops after radix_tree_iter_retry
has been added to the -mm tree.  Its filename is
     radix-tree-fix-oops-after-radix_tree_iter_retry.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/radix-tree-fix-oops-after-radix_tree_iter_retry.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/radix-tree-fix-oops-after-radix_tree_iter_retry.patch

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------------------------------------------------------
From: Konstantin Khlebnikov <redacted>
Subject: 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 <redacted>
Cc: Matthew Wilcox <redacted>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ohad Ben-Cohen <redacted>
Cc: <redacted>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/radix-tree.h |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff -puN include/linux/radix-tree.h~radix-tree-fix-oops-after-radix_tree_iter_retry include/linux/radix-tree.h

--- a/include/linux/radix-tree.h~radix-tree-fix-oops-after-radix_tree_iter_retry
+++ a/include/linux/radix-tree.h

@@ -400,7 +400,7 @@ void **radix_tree_iter_retry(struct radi
  * @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
 			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))

_

Patches currently in -mm which might be from koct9i@gmail.com are

mm-replace-vma_lock_anon_vma-with-anon_vma_lock_read-write.patch
radix-tree-fix-oops-after-radix_tree_iter_retry.patch