The patch titled
lib-radix-treec-fix-overflow-in-radix_tree_range_tag_if_tagged-update
has been added to the -mm tree. Its filename is
lib-radix-treec-fix-overflow-in-radix_tree_range_tag_if_tagged-update.patch
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------------------------------------------------------
Subject: lib-radix-treec-fix-overflow-in-radix_tree_range_tag_if_tagged-update
From: Jan Kara <jack@xxxxxxx>
below is an updated version of the fix. The core of the fix is the same,
it just includes a few more comments updates and a check in
tag_pages_for_writeback() to avoid cycling indefinitely.
Signed-off-by: Jan Kara <jack@xxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Nick Piggin <nickpiggin@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/radix-tree.c | 2 ++
mm/page-writeback.c | 3 ++-
2 files changed, 4 insertions(+), 1 deletion(-)
diff -puN lib/radix-tree.c~lib-radix-treec-fix-overflow-in-radix_tree_range_tag_if_tagged-update lib/radix-tree.c
--- a/lib/radix-tree.c~lib-radix-treec-fix-overflow-in-radix_tree_range_tag_if_tagged-update
+++ a/lib/radix-tree.c
@@ -625,6 +625,8 @@ EXPORT_SYMBOL(radix_tree_tag_get);
*
* The function returns number of leaves where the tag was set and sets
* *first_indexp to the first unscanned index.
+ * WARNING! *first_indexp can wrap if last_index is ULONG_MAX. Caller must
+ * be prepared to handle that.
*/
unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root,
unsigned long *first_indexp, unsigned long last_index,
diff -puN mm/page-writeback.c~lib-radix-treec-fix-overflow-in-radix_tree_range_tag_if_tagged-update mm/page-writeback.c
--- a/mm/page-writeback.c~lib-radix-treec-fix-overflow-in-radix_tree_range_tag_if_tagged-update
+++ a/mm/page-writeback.c
@@ -836,7 +836,8 @@ void tag_pages_for_writeback(struct addr
spin_unlock_irq(&mapping->tree_lock);
WARN_ON_ONCE(tagged > WRITEBACK_TAG_BATCH);
cond_resched();
- } while (tagged >= WRITEBACK_TAG_BATCH);
+ /* We check 'start' to handle wrapping when end == ~0UL */
+ } while (tagged >= WRITEBACK_TAG_BATCH && start);
}
EXPORT_SYMBOL(tag_pages_for_writeback);
_
Patches currently in -mm which might be from jack@xxxxxxx are
origin.patch
lib-radix-treec-fix-overflow-in-radix_tree_range_tag_if_tagged.patch
lib-radix-treec-fix-overflow-in-radix_tree_range_tag_if_tagged-update.patch
linux-next.patch
aio-do-not-return-erestartsys-and-friends-from-aio.patch
reiser4.patch
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