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| author | Jan Kara <jack@suse.cz> | 2010-08-19 14:13:33 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-20 09:34:55 -0700 |
| commit | d5ed3a4af77b851b6271ad3d9abc4c57fa3ce0f5 (patch) | |
| tree | f06894404e4af25051e8918bfd3fdac95974fc97 /mm/page-writeback.c | |
| parent | f2e41e910320197d55b52e28d99a07130f2ae738 (diff) | |
| download | linux-d5ed3a4af77b851b6271ad3d9abc4c57fa3ce0f5.tar.gz | |
lib/radix-tree.c: fix overflow in radix_tree_range_tag_if_tagged()
When radix_tree_maxindex() is ~0UL, it can happen that scanning overflows index and tree traversal code goes astray reading memory until it hits unreadable memory. Check for overflow and exit in that case. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Christoph Hellwig <hch@lst.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page-writeback.c')
| -rw-r--r-- | mm/page-writeback.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 7262aacea8a2..c09ef5219cbe 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -836,7 +836,8 @@ void tag_pages_for_writeback(struct address_space *mapping, 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); |